75 LJet will not fire, finishing restoration Options

[timothy_nd28]

Okay, with one meter lead on pin 10 (ECU connector) put the other meter lead on pin 5, then 16, then 17. You should have 12volts reading on your meter on all. (ignition switch turn to on while checking)

After that, check the resistance of pin 13 to ground.

[malcolm2]

Okay, with one meter lead on pin 10 (ECU connector) put the other meter lead on pin 5, then 16, then 17. You should have 12volts reading on your meter on all. (ignition switch turn to on while checking)

After that, check the resistance of pin 13 to ground.

SOmething different this time.

10 & 5 = 12v
10 & 16 = 7v and rising 7.01...7.04...7.1...
10 & 17 =5.6v

13 to ground meter on 2k = 1.78

[timothy_nd28]

Pin 5, 16 and 17 should all be grounds. This could be the problem. The resistance check was for the CHT, which proves that you have it installed

[malcolm2]

Pin 5, 16 and 17 should all be grounds. This could be the problem. The resistance check was for the CHT, which proves that you have it installed

Crazy voltage does seem to be a problem. So I should have gotten 12 volts between 10 and any ground? what does that mean? Ground wire in the FI harness pinched, torn, broken?

[timothy_nd28]

You should of had 12 volts from pin 10 to 5,,pin 10 to 16 and pin 10 to 17. Being that you don't have 12volts from 2 of the 3, indicates a faulty ground somewhere. I'm not sure if those 3 (pin 5,16,17) are the same wires that goes to the tin? The schematic just tells me that they all tie to ground. In your case, it's not. Maybe Jeff can chime in and enlighten us to where these 3 wires tie to ground.

[malcolm2]

You should of had 12 volts from pin 10 to 5, pin 10 to 16 and pin 10 to 17. Being that you don't have 12volts from 2 of the 3, indicates a faulty ground somewhere. I'm not sure if those 3 (pin 5,16,17) are the same wires that goes to the tin? The schematic just tells me that they all tie to ground. In your case, it's not. Maybe Jeff can chime in and enlighten us to where these 3 wires tie to ground.

We shall see. I would expect somewhere to be IN THE HARNESS, right? I would hate to tear into my new harness, but it is seeming that is needed, or send it back and let Jeff do it. He can probably check his records and see if he put new wires in, or if not, maybe an old one broke.

Thanks.... (SO FAR anyway)

Clark

[timothy_nd28]

Yah, don't tear into your fresh harness. Do you have the 3 wires coming from the harness to the engine tin ground connection? If so, consider running a temp jumper from that to the negative battery terminal, then recheck to see if your voltages came back on the ECU connector

[timothy_nd28]

Is it possible to remove the black plastic ECU connector cover, so the wires can be exposed? If this is possible, you could jump pin 16 and 17 to ground, then try starting your car.

[malcolm2]

Yah, don't tear into your fresh harness. Do you have the 3 wires coming from the harness to the engine tin ground connection? If so, consider running a temp jumper from that to the negative battery terminal, then recheck to see if your voltages came back on the ECU connector

Yes the ground wires are present and connected to the top of the engine. I'll try some jumping.

Clark

[malcolm2]

Yah, don't tear into your fresh harness. Do you have the 3 wires coming from the harness to the engine tin ground connection? If so, consider running a temp jumper from that to the negative battery terminal, then recheck to see if your voltages came back on the ECU connector

Yes the ground wires are present and connected to the top of the engine. I'll try some jumping.

Clark

TAKE THAT BACK. One had popped off. The new female connector on the FI harness was a bit too wide to stay on the blade. I closed the gap and installed. Then checked the voltages again and now I have 12 volts between
10 and 5,
10 and 16 and
10 and 17.

The car still did not start.

[timothy_nd28]

Good, but we are running out of things to check. Let's double check the continuity between pin one on the ECU plug to the neg terminal on the ignition coil. You are certain that you have spark at one of the plugs?

[malcolm2]

Good, but we are running out of things to check. Let's double check the continuity between pin one on the ECU plug to the neg terminal on the ignition coil. You are certain that you have spark at one of the plugs?

Pin 1 and negative had good continuity between them.

I have checked the spark via several methods over the past 2 days. I bought a spark tester... It lit up, I cranked and a buddy ground the plug, it sparked.

Just to be sure I just pulled a plug and laid it down to ground it and watched thru the back window as I started... It also sparked: click, click click and I saw the spark jumping.

There is ZERO fuel on that plug. The injectors don't seem to be opening up. I have heard about starting cars with starting fluid in the intake. We tried that last night too, but no luck. Any other tricks to at least burn some fuel?

[timothy_nd28]

The car will run off ether, pull off the AFM and squirt it directly in the rubber boot. You should also verify that the injectors are not firing, by pulling one and placing it into a glass jar. It is exceedingly rare, but the ECU could be at fault here.

You have spark, and fuel pressure. You also have power going to the ECU on pin 10, and all the grounds pins 5, 16,17 fixed. We checked the continuity of all injectors and resistor pack by verifying voltage on pins 14,15,32 and 33. The CHT is present and within spec as well as the continuity of pin 1 to the ignition coil. I'm speculating that you have a bad brain unit. But before you order a new one, pull a injector and make sure it's not spraying fuel.

[malcolm2]

The car will run off ether, pull off the AFM and squirt it directly in the rubber boot. You should also verify that the injectors are not firing, by pulling one and placing it into a glass jar. It is exceedingly rare, but the ECU could be at fault here.

You have spark, and fuel pressure. You also have power going to the ECU on pin 10, and all the grounds pins 5, 16,17 fixed. We checked the continuity of all injectors and resistor pack by verifying voltage on pins 14,15,32 and 33. The CHT is present and within spec as well as the continuity of pin 1 to the ignition coil. I'm speculating that you have a bad brain unit. But before you order a new one, pull a injector and make sure it's not spraying fuel.

Done, pulled an injector and NO FUEL in the cup. I'll give the spray thing a try too.

I bought a grab bag of FI stuff some time back. I needed 1 piece but the guy wanted to get rid of everything. So I have a 2nd Brain, no idea of the condition, but it is covered with TAR. I have put that in and still no start. I understand it is rare to have a bad ECU, but I figured it was even less probable to have 2 bad ones. Anyway, same result.

Guess I'll start searching for one.

You never made mention of the timing. I have not really set the timing to anything past build setting of 0TDC. I figured I could at least get something out of it. And with no fuel, I guess that is not an issue yet, thoughts?

Thanks so much for all your suggestions. If you get a wild idea, let me know, I'm open.

Clark

[timothy_nd28]

I have little faith with parts laying in some box. Just to make me feel better, pull a injector and insert it into a jar. Pull the ECU connector off, and with one end of the jumper tied to ground, touch the other side to either 14,15,32 or 33. One of those pins will cause that injector to fire. (ignition switch in the on position)

[malcolm2]

I have little faith with parts laying in some box. Just to make me feel better, pull a injector and insert it into a jar. Pull the ECU connector off, and with one end of the jumper tied to ground, touch the other side to either 14,15,32 or 33. One of those pins will cause that injector to fire. (ignition switch in the on position)

I was hopeful, but NO SQUIRT. I did get alittle spark at each connector. I pulled #4 which I have checked continuity back to the ECU connector as 33. For kicks I did touch the other connections, 14, 15, and 32, but nothing but a small spark at the connector but no squirt.

Does this lead us to the injectors? ALL 4? I will have to check my records, but I sent them off for testing, etc... and have the document, somewhere.

[timothy_nd28]

How fancy is your meter, does it check dc amps? You have 30 some psi behind each injector. They should spray like holy hell when you ground them out at the ECU connector. So maybe your ECU is okay, I'm glad we did this last ditch effort type of test! lol

[malcolm2]

How fancy is your meter, does it check dc amps? You have 30 some psi behind each injector. They should spray like holy hell when you ground them out at the ECU connector. So maybe your ECU is okay, I'm glad we did this last ditch effort type of test! lol

No amps on this meter. There may be one in the neighborhood to borrow. I almost snagged an amp meter from work for this weekend testing. I will go get it, if I can't round one up down the street.

Fuel pressure has dropped to about 10. Should I pump it up and try again? 10 seems like enough to test. Shouldn't I have heard a click, even if no fuel pressure was there?

Clark

[timothy_nd28]

Yah, you should hear a slight click, but I think the pintle shaft thingys are seized. Do you have a spare one in that box of yours?

Go ahead and pump up the system again, it shouldn't matter but the added pressure may help free the seized FI's.

[malcolm2]

Yah, you should hear a slight click, but I think the pintle shaft thingys are seized. Do you have a spare one in that box of yours?

Go ahead and pump up the system again, it shouldn't matter but the added pressure may help free the seized FI's.

Pressure up to 30 but still no squirt.

I have no extra injectors in my grab bag box of tar covered FI stuff.