Hi everyone,

sorry for basically posting the same problem I've been chasing for 3months...

1972 1.7 with Djet

I've Done nearly everything... honestly.. tested and re-tested... This weekend I even changed the FI harness completely..... So I guess I'm going to start over from scratch and give it one more go around.

The good news is that my problem has gotten worse and now its to the point of not starting, so it should be easier to find than when it was intermittent.

The symptoms.
when the car is cold (or sits for 30 minutes) it will start and then run for 30-60 seconds. During this running time it is smooth, hitting on all cylinders, and sounds good....

However, after 30 seconds it dies and will not restart until it has sat for 30 minutes.

During the "dying" it shows spark at the timing light and Fuel Pressure on a guage... During its no start period, it continues to have spark at each plug wire, and continues to have 29.6psi of fuel pressure at the guage...

So I've got to think its FI related. I swear, I've tested everything except for the cold start sensor, and TPS....
but I guess I had better start over...

Is there something with this type of symptom I should check first?

I thought FI points, but have tried 3 sets yesterday to no avail. I also ohm tested the 25 pins on the ECU and they were all fine.

Is there something in the regulator board that would cause this problem, other than the power to the Fuel pump (since I have pressure still).

thanks everyone.
brant

Sounds like CHT. Or... does it start when cold and the cold start injector is unplugged?

Throw another brain in it.. Dont subscribe to the old school threory of: "they work or they dont work"

You could also have a weak relay... not holding in.


B

Is it not starting because its a really rich fuel mix? Check by smelling the tailpipe after trying to start it. It should smell like gas but not flooded with gas. A bad CHT will flood the engine. As Brad stated "try another ECU "because there could be something wonky with the one you have.

Geoff

with the CHT problem

A quote from Brad Ander's site:

"Warm-Up Transition: When the engine is below its normal operating temperature, more fuel is needed to account for condensation and incomplete mixing until the engine is fully warmed up. The TS2 sensor is a negative-temperature-coefficient resistor (resistance goes down as temperature goes up), mounted on the cylinder head. The ECU has a warm-up enrichment circuit that senses the resistance of the TS2 sensor and corrects the mixture for the engine temperature."

VERY helpful website, I'd bookmark it if you already haven't.

http://members.rennlist.com/pbanders/

Don't rule out the relay board. Mine drove me crazy, thinking it was the FI system,. After going through everything twice, I was pushing on a relay when it started to die and that made it recover. (fuel pump was dying when relay got warm-but I thought it was getting too rich) Stripped/resoldered board, and away I went. Ran better, too, after checking/recalibrating stuff! (new CHT didn't hurt, I'm sure)

Hang in there...

Eric '72 D-Jet

He is correct. I run my hand under the relay board and feel for imperfections.. while I'm trying to make something run I push up on the bottom and down from the top on the relay's.


B

The asumption is that the other parts/systems of the car are in good working shape. If the relay board is cracked or a POS you will never solve the problem, you are just chasing your tail.
Good grounds are another must! A oily grimy engine means problems with the electrical system/FI.
Careful checking of each part is a must, making sure its clean and has good grounding and electrical contact.
I re-installed my Djet tossing the carbs 5 years ago and didn't the info we do now. Stay with it and you will solve the problem.

Geoff

I promised myself I wouldn't say..."already tried that" and I would be open minded... but I think I've got the CHT covered.... my old one tested good, but I bought and installed a new one which also tested good...

doesn't seam rich when its not starting.. no fuel smell..
and 30 seconds of running doesn't hugely affect the reading on the CHT anyways... its readings are more effected by ambient (60F versus 95F) depending upon the temp on the day I'm working on it...

I HAVE NOT changed out the regulator board...
I thought it only controlled the fuel pump..
but since its about the only thing I haven't changed, It could well be affecting something else.....

SO... I will push/wiggle on it..
Does anyone have a spare they want to sell to me?

I switched the ECU once, but since then the symptom has changed.. I'll switch it again and have a spare of the same number....

Thanks everyone.... thanks a ton...
brant

Marc,

yep.. electrical to cold start injector has no effect.
and yesterday I bypassed the injector completely by removing the fuel lines to it and still it would not start.

everyone,

Remind me.. besides the fuel pump.. what else does the regulator board control that would cause a no start condition....?

(there is that 4-pin connector on the board [I,II,III,IV] that feeds power to the ECU, and power to the cold start)

b

If it were me I'd put a pressure gauge on the fuel system, check for correct pressure when cranking. I would then jumper the fuel pump relay for the following stuff. Then I would pull all 4 injectors and put each in a container and crank the engine to see if they squirt when cranking. I would also check the TPS to see if opening the throttle causes the injectors to fire. Then I would check the MPS connector and hose to make sure it is okay. On our 1974 2l if it comes unplugged the engine stops immediately. On our 1974 the vac hose split once and the engine would not run. I would also check the second temp connection under the plenum to make sure it is connected okay and has correct resistance as ours came unplugged once and when the wire grounded, the engine stopped. I would also check spark at each plug since the points could be affected by a slight amount of heat. The only other thing I could think of is the FI points and the brain and you've covered those.

John or anyone,

one thing I haven't tested yet is the TPS...
Will a bad TPS case a no start condition?
will it cause a no start irrelevant of throttle position?

(when I tested the 25pin ECU connector I was able to get all 10 different continuities from the TPS, and if memory serves there was a pin for TPS idle that measured correctly also)

regarding the cold start sensor... I removed it once and tested it... thought it was bad, but found out my ohm meter was bad.... So your right, I do not know if this part is good/bad...

Question, If I unplug the wire to this sensor it is supposed to slightly enrichen the mixture... unless if was shorting somehow, I didn't suspect that it would cause a no start.. in fact it is not even directly tied to the ECU, but rather gets its power from the starter circuit in the regulator board... What are your thoughts on this?
It seems like unplugging it would solve any possible short, so maybe I'll try that.

brant

The car will start and run without the TPS hooked up.

I agree with JR. By pass the relay for the fuel pump and make damn sure it runs all the time.

How about the fuel lines ?? Do you have them connected to the engine/regulator correctly ?? Backwards fuel lines cause all kinds of issues.

What kind of ignition ??


B

Brad,

first let me thank you for your time...
I'll next jump/bypass the Fuel pump relay....

I can hear the pump when key is in (before motor running).. and I have fuel pressure on the guage even when cranking it and it doesn't start... so I thought I was safe on the fuel pressure side of the equation...

I'll double check the routing of the lines too... but before the problem became a no-start it used to be intermittent...

and 2 seperate weekends I put 500miles on the car each, with this as an infrequent intermittent problem... so I thought I had the fuel lines working then.... but can't hurt to double check...

hey if you don't tow me out a roller in october, maybe I should try Jenny's Idea and pay you to stop and fix this sucker....ha...

oh.. almost forgot.. ignition.. I had put a crane in it, and was suspecting that so I sent it back to the factory in FLA.. they said it was fine. I put the points back in... I have FLASH on the timing light at all 4 plug wires when I'm turning it over and it won't re-start.

I'm liking the regulator board Idea... I know there are the 4 white wires (5 actually) on the board in the 4prong pin... Is there any other wires on the regulator board that control/feed the FI?

have a good night
brant

I didnt know this car ran in the past.. so the fuel pump lines are more than likely correct.

Have you done a compression check ?? Are the valves tight ??

Are the plugs gas fouled now that you have pumped raw fuel all over them each time you crank the car and it doesnt start ?

Yank the injectors like the guy above said and fire them into a container while cranking the car (coil + wire OFF)


B

Brad,

Yeah.. I think I tested every single thing (well maybe not the TPS, relay board, and cold start sensor)... but dang near everysingle thing...

so I'll pull the injectors again and check for spray patterns...

I highly suspect that when I'm in a no start mode that there will be Zero spray pattern and that the no start is being caused by no fuel..... (why there is no fuel, I'm not sure as the pressure is good and the spark is good)..

Sunday I tried 2 distributors and 3 sets of FI points....
but tonight I'll pull them and double check that.
I said I'd start at square one, so I will...
good idea and I need to verify the fuel issue

thanks again
brant

OK.. I have seen 3 cars this year with trigger point connectors that push out when you push down on them. Buy a noid light from FLAPS and find out if you have injectors that are firing.

B