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Groosh
Hi. I recently bought a '74 1.8 and am looking for help to get it running. It has the original fuel injection and ran late last year according the previous owner.

Here's what I know after reading many posts in the forum and working on it. Thanks to everybody who contributes, I couldn't have gotten this far without your help.

- The dual relay is bad I believe. After wiring it all back up, there is power from the ignition to both the start wire and run wire but no power to the fuel pump. I'm jumping the pump currently to test
- All relays in the board work
- Fuel pressure gauge shows 35psi on startup. I didn't install this gauge but seems to work ok
- Will fire with starting fluid

I'm thinking I must be pretty close and suspect the car isn't getting fuel but the gauge shows pressure?
TheCabinetmaker
An inline pressure gauge will show pressure in the system, but that doesn't mean fuel is getting past the injectors.
Groosh
QUOTE(The Cabinetmaker @ Jun 5 2016, 11:28 AM) *

An inline pressure gauge will show pressure in the system, but that doesn't mean fuel is getting past the injectors.

Thanks. So if it firing on fluid the injectors are working but somehow I need to figure out if they are getting fuel. The fuel pressure gauge is off the right side rail. Any ideas on what to try next?
r_towle
Stick a pencil in the round intake end of the air-fuel meter.
Open the flapper door
You use the pencil to hold the door open, not to run the car, just to test
Turn on key to run
Do you hear the fuel pump?
Groosh
QUOTE(r_towle @ Jun 5 2016, 11:35 AM) *

Stick a pencil in the round intake end of the air-fuel meter.
Open the flapper door
You use the pencil to hold the door open, not to run the car, just to test
Turn on key to run
Do you hear the fuel pump?

Can there be pressure in the fuel system but no fuel? Maybe the filter or something is clogged before the gauge?

- Fuel pump works
timothy_nd28
Rich's test is a good one, it's testing if your fuel pump turns on and it's also testing if part of the dual relay is working.
jim_hoyland
And the 6 pin connector is plugged into the AFM ?
Groosh
QUOTE(timothy_nd28 @ Jun 5 2016, 11:59 AM) *

Rich's test is a good one, it's testing if your fuel pump turns on and it's also testing if part of the dual relay is working.

The relay isn't working as far as I know but I'm jumping the fuel pump right now. Power is getting to the relay properly from the ignition but not turning on the pump. Will that alter something else?

So if it fires under starting fluid, has fuel pressure but apparently no fuel, maybe it's as simple as a clogged filter?
timothy_nd28
QUOTE(Groosh @ Jun 5 2016, 11:24 AM) *

Hi. I recently bought a '74 1.8 and am looking for help to get it running. It has the original fuel injection and ran late last year according the previous owner.

Here's what I know after reading many posts in the forum and working on it. Thanks to everybody who contributes, I couldn't have gotten this far without your help.

- The dual relay is bad I believe. After wiring it all back up, there is power from the ignition to both the start wire and run wire but no power to the fuel pump. I'm jumping the pump currently to test
- All relays in the board work
- Fuel pressure gauge shows 35psi on startup. I didn't install this gauge but seems to work ok
- Will fire with starting fluid

I'm thinking I must be pretty close and suspect the car isn't getting fuel but the gauge shows pressure?



This comment has me concerned, what was de-wired? The dual relay does many things, one being the fuel pump but more importantly it turns on the Ljet computer.
emoze
NO - if it fires on start fluid but won't run

- the injectors are either stuck or not pulsing - put a NOID Light on the injector plugs to narrow it down

QUOTE(Groosh @ Jun 5 2016, 12:30 PM) *

if it firing on fluid the injectors are working but somehow I need to figure out if they are getting fuel. The fuel pressure gauge is off the right side rail. Any ideas on what to try next?
Groosh
QUOTE(timothy_nd28 @ Jun 5 2016, 12:16 PM) *

QUOTE(Groosh @ Jun 5 2016, 11:24 AM) *

Hi. I recently bought a '74 1.8 and am looking for help to get it running. It has the original fuel injection and ran late last year according the previous owner.

Here's what I know after reading many posts in the forum and working on it. Thanks to everybody who contributes, I couldn't have gotten this far without your help.

- The dual relay is bad I believe. After wiring it all back up, there is power from the ignition to both the start wire and run wire but no power to the fuel pump. I'm jumping the pump currently to test
- All relays in the board work
- Fuel pressure gauge shows 35psi on startup. I didn't install this gauge but seems to work ok
- Will fire with starting fluid

I'm thinking I must be pretty close and suspect the car isn't getting fuel but the gauge shows pressure?


This comment has me concerned, what was de-wired? The dual relay does many things, one being the fuel pump but more importantly it turns on the Ljet computer.


The owner pulled apart the dual relay - fuel pump/injector side - which I had to wire back together because he said there was a "fuel pump issue" which I think is the relay. Everything else seems to be intact relating to the engine and the other half of the dual relay. The lights, radio and gauges are another story.

Oh. There is one black with green stripe wire that is not connected. Not sure where that goes? Please don't judge the wire connectors. I'm just getting it together so it runs and will clean this up later.

ejm
QUOTE(Groosh @ Jun 5 2016, 07:23 PM) *

- Will fire with starting fluid

Oh. There is one black with green stripe wire that is not connected. Not sure where that goes?

The wire is for an oil temp gauge if your car has one. Did you drain the tank and put some fresh fuel in?
timothy_nd28
I'm not sure if I can see the jumper from 88Y to 88Z, other than that it looks wired correctly.

With the ignition set to on and the ECU connector unplugged, do you get 12vdc at pin 10 to ground?

What was the results with Rich's test with the pencil in the AFM?
Twonicks001
I know this sounds overly simplistic but it had me going for a week or so. Do you have 12v at the fuel pump plug? My plug was bad. When I cut it off and spliced in my own clips to the pump, I was in business. Just a thought.

Good luck.
motorvated
If the injectors are not firing, you might want to confirm that the ground wire from the fuel injection harness is connected to a good clean spot on the engine block (not on the fan housing), and be sure the injector resistor pack is installed and the connector is clean. If it's there, carefully pull the connector apart a few times for a better connection. Injectors don't get any power without the resistor pack installed and therefore won't fire. Wires can break off of the resistor pack too, so be careful with it.
Groosh
QUOTE(r_towle @ Jun 5 2016, 11:35 AM) *

Stick a pencil in the round intake end of the air-fuel meter.
Open the flapper door
You use the pencil to hold the door open, not to run the car, just to test
Turn on key to run
Do you hear the fuel pump?

So I put a pencil in the door and did not hear the pump run. Not sure if I'm doing things right. I'm still jumping the fuel pump to run it but not getting injectors to fire.
Groosh
QUOTE(motorvated @ Jun 6 2016, 04:33 AM) *

If the injectors are not firing, you might want to confirm that the ground wire from the fuel injection harness is connected to a good clean spot on the engine block (not on the fan housing), and be sure the injector resistor pack is installed and the connector is clean. If it's there, carefully pull the connector apart a few times for a better connection. Injectors don't get any power without the resistor pack installed and therefore won't fire. Wires can break off of the resistor pack too, so be careful with it.

The ground looks clean and the resistor pack looks good. The wires are not frayed and took it apart several times to hopefully get a clean connection.
Groosh
QUOTE(timothy_nd28 @ Jun 5 2016, 04:24 PM) *

I'm not sure if I can see the jumper from 88Y to 88Z, other than that it looks wired correctly.

With the ignition set to on and the ECU connector unplugged, do you get 12vdc at pin 10 to ground?

What was the results with Rich's test with the pencil in the AFM?


The jump is there. I tried to unplug the ECU and test for 12vdc from any pin and did not seem to get any.

I also bought a new relay which came today. It didn't help. I did notice that the fuel ground from the relay is hot. I traced it to the motor where it is grounded and get a volts from it.
r_towle
Without more accurate testing I would strongly suggest your AFM may need to be replaced, and your wiring needs to be redone properly.
timothy_nd28
Adding new parts just confounds the problem. Remove the fuel pump jumper and re-install the old dual relay.

When you tested for voltage on pin 10 of the ECU connector, was the ignition switch to on?

If so, let's do one thing before continuing with further tests. On the ignition coil, there should be a single wire on the (+) side terminal. Remove this wire, and tape it off. It's bad for the ignition coil and points when doing tests with the ignition key set for on, but the engine not running.

After the wire has been removed, we need to measure some voltages at the dual relay. With the meter set to DC, put the black lead on the negative battery post. Now with the red meter lead, probe pin 88z, then 88a and 88b. Report back what you see. This above test is done with the ignition key set to the "on or run" position.
timothy_nd28
Also if you don't already own these, run to RadioShack and pick this up
Click to view attachment
Groosh
QUOTE(timothy_nd28 @ Jun 9 2016, 11:01 AM) *

Adding new parts just confounds the problem. Remove the fuel pump jumper and re-install the old dual relay.

When you tested for voltage on pin 10 of the ECU connector, was the ignition switch to on?

If so, let's do one thing before continuing with further tests. On the ignition coil, there should be a single wire on the (+) side terminal. Remove this wire, and tape it off. It's bad for the ignition coil and points when doing tests with the ignition key set for on, but the engine not running.

After the wire has been removed, we need to measure some voltages at the dual relay. With the meter set to DC, put the black lead on the negative battery post. Now with the red meter lead, probe pin 88z, then 88a and 88b. Report back what you see. This above test is done with the ignition key set to the "on or run" position.


Ok. I tried pin 10 again with the switch on but did not read any volts.

After taping off the positive lead to the coil, I tested the following with the ignition switch on:

88z - 12 volts
88a - nothing
88b - nothing

timothy_nd28
Okay, use one of the jumper wires you just bought from Radio Shack and jump pin 86C on the dual relay to the positive battery terminal. Then recheck for voltages as I described in the earlier step.
Groosh
QUOTE(timothy_nd28 @ Jun 10 2016, 02:05 PM) *

Okay, use one of the jumper wires you just bought from Radio Shack and jump pin 86C on the dual relay to the positive battery terminal. Then recheck for voltages as I described in the earlier step.


86c was already getting proper volts from the ignition switch in the "on" position so I didn't jump it. However I still get no other readings on 88a or 88b.
timothy_nd28
Okay, jump pin 85 at the dual relay to the negative battery post. Redo same test as above.
Groosh
QUOTE(timothy_nd28 @ Jun 11 2016, 05:15 AM) *

Okay, jump pin 85 at the dual relay to the negative battery post. Redo same test as above.

Heard the relay click for the first time and got 12 volts on 88a and 88b.
timothy_nd28
What about pin 10 at the ECU?
Groosh
QUOTE(timothy_nd28 @ Jun 11 2016, 09:54 AM) *

What about pin 10 at the ECU?

I'm not getting any power off of the ECU at pin 10.
timothy_nd28
We need to make sure that you are indeed probing pin 10 of the ECU connector. So, put your meter on a low resistance setting. Then put one meter lead on the negative (-) terminal of the ignition coil, put the other lead on what you think is pin 1 of the ECU connector, you should get 0 ohms
Groosh
QUOTE(timothy_nd28 @ Jun 11 2016, 11:30 AM) *

We need to make sure that you are indeed probing pin 10 of the ECU connector. So, put your meter on a low resistance setting. Then put one meter lead on the negative (-) terminal of the ignition coil, put the other lead on what you think is pin 1 of the ECU connector, you should get 0 ohms

Well, I did get 0 ohms. As far as me doing it right? I hope so.
timothy_nd28
We might as well check some other wires, I'm starting to doubt your wiring harness.

Key on, wire still off (and taped) the ignition coil, jumper wire still on pin 85 (dual relay) to negative battery terminal, meter set for DC volts, put one meter lead on the negative battery post. Now, make sure you still have 12vdc on pins 88a and 88b of the dual relay, if so you can continue.
Leave one meter lead on the negative battery post. Put the other meter lead on pin 14 of the ECU connector, you should get 12vdc. If so, move the meter lead from pin 14 and place it on pin 15, again you should see 12vdc. Move the meter lead from pin 15, and place it on pin 32, you should see 12vdc. Finally, move the meter lead from pin 32 and move it to pin 33, you should see 12vdc.

This tests the continuity of the wiring to the fuel injector, continuity of the injector itself, continuity of the wires leaving the injector to the resistor pack, continuity of the resistors. This is a good test, kinda checks everything.

After all that, put one meter lead on the positive battery post. With the other meter lead, probe pins: 5,16, and 17 on the ecu connector. You should have 12volts on each pin.

If all that passes, recheck pin 10 on the ecu connector for 12vdc. Pin 10 is a very important pin. This pin supplies power to the ECU, no power to this pin will keep the computer off.
Groosh
QUOTE(timothy_nd28 @ Jun 11 2016, 12:22 PM) *

We might as well check some other wires, I'm starting to doubt your wiring harness.

Key on, wire still off (and taped) the ignition coil, jumper wire still on pin 85 (dual relay) to negative battery terminal, meter set for DC volts, put one meter lead on the negative battery post. Now, make sure you still have 12vdc on pins 88a and 88b of the dual relay, if so you can continue.
Leave one meter lead on the negative battery post. Put the other meter lead on pin 14 of the ECU connector, you should get 12vdc. If so, move the meter lead from pin 14 and place it on pin 15, again you should see 12vdc. Move the meter lead from pin 15, and place it on pin 32, you should see 12vdc. Finally, move the meter lead from pin 32 and move it to pin 33, you should see 12vdc.

This tests the continuity of the wiring to the fuel injector, continuity of the injector itself, continuity of the wires leaving the injector to the resistor pack, continuity of the resistors. This is a good test, kinda checks everything.

After all that, put one meter lead on the positive battery post. With the other meter lead, probe pins: 5,16, and 17 on the ecu connector. You should have 12volts on each pin.

If all that passes, recheck pin 10 on the ecu connector for 12vdc. Pin 10 is a very important pin. This pin supplies power to the ECU, no power to this pin will keep the computer off.


Shoot. I was doing it wrong before and now have myself straightened out. Here is where I'm getting 12vdc with the key "on"

- 10 pin
- 15 pin
- 32 pin
- 5, 16, 17

Not getting volts on:
- 14, 33



timothy_nd28
Pin 14 and 33 are two of the four injectors. Disconnect the resistor pack and post a picture
timothy_nd28
The resistor pack should look similar to this:
Click to view attachment

Once you disconnect the connector to this device, set your meter for resistance and put one meter lead at the center pin (on the connector leading to the resistor pack). Probe the outside pins with the other meter lead. You should get a pretty low resistance on those four pins.

These wires are frail and tend to break. It would be nice to rule this out before diving into a more complicated test procedure.
Groosh
QUOTE(timothy_nd28 @ Jun 12 2016, 05:43 PM) *

The resistor pack should look similar to this:
Click to view attachment

Once you disconnect the connector to this device, set your meter for resistance and put one meter lead at the center pin (on the connector leading to the resistor pack). Probe the outside pins with the other meter lead. You should get a pretty low resistance on those four pins.

These wires are frail and tend to break. It would be nice to rule this out before diving into a more complicated test procedure.

The wires look good. The resistance is even across all four pins. Yes, I kick it old school with my father's old meter.
timothy_nd28
Old meters like that are awesome! Go ahead and reinstall the resistor pack, then try re-seating each fuel injector connector. So, remove the 2 pin electrical connector from a fuel injector, then push it back on. Do this 13 times for each fuel injectors' connector. After all this is done, and assuming that jumper is still on pin 85 of the dual relay and the ignition key is on,,put one meter lead on the negative battery post. With the other meter lead, probe pins 14,15,32,33 to see if they have 12volts, more importantly does pin 14 and 33 now have voltage after reseating the fuel injector connectors?

If the above instructions fail to remedy pins 14 and 33 then lets continue.

We need to know what injectors correlate to pins 14 and 33. To find this out, we can use the injectors that do work, pins 15 and 32. Put your meter lead on pin 15 and with the same test conditions as the paragraph above, you should get 12volts. Start by unplugging one fuel injector at a time while watching your meter. If the 12volts drops out when unplugging, then that injector matches up with pin 15. If 12volts is still present after unplugging one fuel injector, simply plug that connector back in and move onto the next fuel injector connector. Rinse and repeat till you find that one injector that makes pin 15 go dead. Repeat the same test but put the meter lead in pin 32, find that other good injector.

Once you find the two good injectors, we now know the two problem injectors.

With the offending fuel injectors, go ahead and remove the connectors for those two. It will be hard to probe these pins with your meter, you may need to fashion a paperclip at the end of your meter lead.

Ok, with the ignition switch set to on and your jumper still on the dual relay, put one meter lead on the negative battery post. We are measuring for 12volts. Probe both pins of each injector harness connector. Of the two pins, only one will show 12volts while the other pin will read nothing, do this for both bad injectors.

Groosh
QUOTE(timothy_nd28 @ Jun 13 2016, 08:13 AM) *

Old meters like that are awesome! Go ahead and reinstall the resistor pack, then try re-seating each fuel injector connector. So, remove the 2 pin electrical connector from a fuel injector, then push it back on. Do this 13 times for each fuel injectors' connector. After all this is done, and assuming that jumper is still on pin 85 of the dual relay and the ignition key is on,,put one meter lead on the negative battery post. With the other meter lead, probe pins 14,15,32,33 to see if they have 12volts, more importantly does pin 14 and 33 now have voltage after reseating the fuel injector connectors?

If the above instructions fail to remedy pins 14 and 33 then lets continue.

We need to know what injectors correlate to pins 14 and 33. To find this out, we can use the injectors that do work, pins 15 and 32. Put your meter lead on pin 15 and with the same test conditions as the paragraph above, you should get 12volts. Start by unplugging one fuel injector at a time while watching your meter. If the 12volts drops out when unplugging, then that injector matches up with pin 15. If 12volts is still present after unplugging one fuel injector, simply plug that connector back in and move onto the next fuel injector connector. Rinse and repeat till you find that one injector that makes pin 15 go dead. Repeat the same test but put the meter lead in pin 32, find that other good injector.

Once you find the two good injectors, we now know the two problem injectors.

With the offending fuel injectors, go ahead and remove the connectors for those two. It will be hard to probe these pins with your meter, you may need to fashion a paperclip at the end of your meter lead.

Ok, with the ignition switch set to on and your jumper still on the dual relay, put one meter lead on the negative battery post. We are measuring for 12volts. Probe both pins of each injector harness connector. Of the two pins, only one will show 12volts while the other pin will read nothing, do this for both bad injectors.


Well go figure. After the car sat for almost a week things tested out differently. I did the pull reset 13x on the fuel injectors:

- 32 is cylinder 2 and gets volts at the 32 pin
- 33 is cylinder 3 and gets volts at the 33 pin
- 14 no volts at pin - injector harness gets 12 volts
- 15 no volts at pin - injector harness gets 12 volts




timothy_nd28
For injectors 4 and 1, is this 12volts at the fuel injector connector? If so, test the resistance across the two pins on the fuel injector itself.
Groosh
QUOTE(timothy_nd28 @ Jun 20 2016, 06:18 AM) *

For injectors 4 and 1, is this 12volts at the fuel injector connector? If so, test the resistance across the two pins on the fuel injector itself.

Yes. Injectors 1 and 4 get 12 volts at the injector connector.

The resistance across all four injectos tests even.
timothy_nd28
Since the injectors all have continuity, the problem lies in a short wire run from the injector's connector to the ECU connector. I highlighted a red box that illustrates the problem area
Click to view attachment

Since you already tested the FI connector of the two failed injectors, and confirmed that you have 12 volts sitting at one of the two pins, confirms that the dual relay is sending voltage thru the resistor pack and is making its way to the fuel injector. Missing voltage at the ECU pins 14 and 15 tells me that there is a break in a wire or a bad connection at one of the connectors.

You can remove the fuel injector connector and reconfirm that you do indeed have 12 volts present on one of the two pins. The other dead pin, you can check the resistance of that pin to the ECU connector, which will be either pin 14 or 15. You should read 0 ohms, but since you are not getting voltage on pins 14 or 15, you may read a high resistance. I bet if you were to jiggle the harness while measuring resistance, you may see things change with your meter.

Be extra observant at the two failed injectors, look at the wires and pins at the injector connector. Same thing for pins 14 and 15 at the ECU connector.

After all that, you have 3 options.

Send your injection harness off to Jeff Bowlsby for repair, or buy a known good used one, or if you are up for it; get a razor blade and split the outer casing of the injection harness and find pin 14/15 wires and repair it yourself.
Groosh
QUOTE(timothy_nd28 @ Jun 20 2016, 07:54 AM) *

Since the injectors all have continuity, the problem lies in a short wire run from the injector's connector to the ECU connector. I highlighted a red box that illustrates the problem area
Click to view attachment

Since you already tested the FI connector of the two failed injectors, and confirmed that you have 12 volts sitting at one of the two pins, confirms that the dual relay is sending voltage thru the resistor pack and is making its way to the fuel injector. Missing voltage at the ECU pins 14 and 15 tells me that there is a break in a wire or a bad connection at one of the connectors.

You can remove the fuel injector connector and reconfirm that you do indeed have 12 volts present on one of the two pins. The other dead pin, you can check the resistance of that pin to the ECU connector, which will be either pin 14 or 15. You should read 0 ohms, but since you are not getting voltage on pins 14 or 15, you may read a high resistance. I bet if you were to jiggle the harness while measuring resistance, you may see things change with your meter.

Be extra observant at the two failed injectors, look at the wires and pins at the injector connector. Same thing for pins 14 and 15 at the ECU connector.

After all that, you have 3 options.

Send your injection harness off to Jeff Bowlsby for repair, or buy a known good used one, or if you are up for it; get a razor blade and split the outer casing of the injection harness and find pin 14/15 wires and repair it yourself.


Hmmmm... I have the injector harness off. I notice a pin on one injector pushed in but all the injector wiring tests good when I connect from the injector plug back to the ECU connector. I also test good from the restistor pack plug to the injector plug.

That being said, there are bad wires. But I'm not sure what to make of it all before I go slicing and dicing.
timothy_nd28
So you have 12volts on pins 14,15,32&33?
Groosh
Thanks to all of Tim's work, I have a repaired fuel injector harness back in the car. Thanks Tim!

The last we left it, I was at the following trying to test the ground.

QUOTE(Groosh @ Jun 11 2016, 08:08 AM) *

QUOTE(timothy_nd28 @ Jun 11 2016, 05:15 AM) *

Okay, jump pin 85 at the dual relay to the negative battery post. Redo same test as above.

Heard the relay click for the first time and got 12 volts on 88a and 88b.

Groosh
Well, I started back at the beginning of our testing.

After taping off the positive lead to the coil, I tested as follows:

- Ignition switch on
- Negative lead from multi meter on battery
- Positive lead touching the following:

88z - 12 volts
88a - 12 volts
88b - 12 volts

88d - will run fuel pump with 12 volts jump wire from positive terminal
86c - will get 12 volts with jump wire from negative battery terminal

timothy_nd28
Try deflecting the air flow meter flap with the ignition switch on, does the fuel pump engage?

Also, measure pins 14,15,32 and 33 by having the ignition switch on, and the meter set for DC volts. Put one meter lead on the negative battery post, and the other meter lead in the ECU sockets 14,15,32,33.
Groosh
QUOTE(timothy_nd28 @ Oct 18 2016, 01:59 PM) *

Try deflecting the air flow meter flap with the ignition switch on, does the fuel pump engage?

Also, measure pins 14,15,32 and 33 by having the ignition switch on, and the meter set for DC volts. Put one meter lead on the negative battery post, and the other meter lead in the ECU sockets 14,15,32,33.


Yes, fuel pump engages with deflected air flow meter and key switched on.

With the meter set to DC 50 and key on, I'm reading 12 volts at ECU sockets 14,15,32,33.

timothy_nd28
Cool, much better results than last time.
timothy_nd28
Car is almost ready to run. I would do one more test to verify the injectors do still work and are spraying fuel. Unclamp all injectors from the manifold, leave the fuel lines attached and electrical connectors plugged in. Find a way to put mason jars under each fuel injector. Set the ignition switch to on and temporarily open the airflow meter flap or jamb a screwdriver inside to keep the flap open.

With a wire, attach one side to the negative battery post. Take the other side of this wire and probe pins 14,15,32,33 at the ecu connector. Watch the fuel injectors as you do this. It should be a mist of fuel spraying, make sure all spray patterns look the same.

Next, take your voltmeter and set it for resistance. Probe pin 13 at the ecu connector while the other lead is on the negative battery post.

Finally, reassemble and prepare the car to start. Make sure you reattach the power wire back on the ignition coil and you remove the screw driver from the airflow meter.
Groosh
QUOTE(timothy_nd28 @ Oct 19 2016, 08:48 PM) *

Car is almost ready to run. I would do one more test to verify the injectors do still work and are spraying fuel. Unclamp all injectors from the manifold, leave the fuel lines attached and electrical connectors plugged in. Find a way to put mason jars under each fuel injector. Set the ignition switch to on and temporarily open the airflow meter flap or jamb a screwdriver inside to keep the flap open.

With a wire, attach one side to the negative battery post. Take the other side of this wire and probe pins 14,15,32,33 at the ecu connector. Watch the fuel injectors as you do this. It should be a mist of fuel spraying, make sure all spray patterns look the same.

Next, take your voltmeter and set it for resistance. Probe pin 13 at the ecu connector while the other lead is on the negative battery post.

Finally, reassemble and prepare the car to start. Make sure you reattach the power wire back on the ignition coil and you remove the screw driver from the airflow meter.


Well, I'm not seeing any fuel come out at all. I first tested this by cranking the car over with little jars under each injector. Only cylinder #2 had a little fuel mist and then it didn't do it again. I tried again by jumping the negative battery post and probing the pins and did not hear or see any sign of fuel coming from the injectors. The fuel pump was running.
timothy_nd28
Ok, I'm very glad that you did this test. First, we must rule out the simple, do you have fuel? What is the fuel pressure at the fuel rail?

A few tests ago you measured 12 volts from pins 14,15,32 and 33 to battery ground. This test proves that you have continuity from the ECU connector thru the wiring harness, the fuel injector itself has continuity, the wiring harness to the dropping resistors has continuity, and finally, the harness to the dual relay has continuity. All of this is a very good thing.

Even though each fuel injector show's continuity, this does not prove that they will work. Mechanically, these injectors could be seized or plugged full of stromberg.gif . Let's do one more test just to prove that these injectors are working electrically.

These injectors are low impedance, I'm pretty sure they are around 2.5 ohms (correct me if I'm wrong). You also have a 6 ohm dropping resistor in series of each fuel injector (resistor pack). Using a simple equation I=E/R, we can solve for current on each injector circuit. Total resistance is around 8.5 ohms, voltage is 13, so we should see something around 1.5 amps.

Many meters will measure amperage's for DC circuits. The meter will usually have something that will say DC A, and they typically measure up to 10 amps. Make sure you don't have your meter set to DC milliamps, as this will blow the meter's internal fuse. Make sure the red meter lead is plugged into the correct port on the meter, DC amp setting usually has its own port.

Now, same test as before. Remove the power wire from the ignition coil, set the ignition switch to on, temporarily deflect the air flow meter flap or jump pin 88d at the dual relay to the positive battery post. Next, insert the red meter lead into socket 14 of the ECU connector, while the black meter lead is touching the negative battery post. You should hear a click at the fuel injector, should also see fuel spraying too. As all of this is going on, observe what your meter is saying, should be somewhere of 1.5 amps.

Repeat this for pins 15, 32 and 33.

If you are seeing 1.5 amps at each injector, and you have verified fuel pressure at the fuel rail, then you send off your injectors to WitchHunters for cleaning.



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