Help needed.

[Cobra]

People,

I am at my wits end. My car won't start.

Sorry, it starts, runs for about 2 seconds and then stops. I can start it again and it does the same thing.

I have tried all the usual, I even borrowed another ECU from Zuffen but still the prob persists.

Has anybody got any ideas?

Please I need inspiration.

 

[Peewee]

Sounds like the AFM signal to the fuel pump isn't working.

The pump turns on when the key is "START" and when the AFM senses air.
Test that circuit.
Try a different AFM, and check the fuel pump is working.
Hotwire the fuel pump is a quick way to test.


btw, did it only just start happening? or is this the first time you have tried?

 

[Lextreme II]

check your alternator...... and charging system....

 

[Cobra]

It has 2 fuel pumps and they both are working perfectly. One for the surge tank and the other is high pressure.

Battery is holding a full charge and alternator charges at 13.8

Being an ICV, there may be a possibility of an earth breakdown. What are your thoughts on what connections I should check first given the symptoms I have detailed?

Brett

 

[Peewee]

Is this the first time it has run?
Or did it just start happening?

 

[Cobra]

The car has been running very well for a while now. I was at traffic lights one day and it just stopped. It started again and drove well for a while and then just stopped again.
That is when the problem reared its ugly head. I had it towed home on a flat bed and it has been in the garage ever since. About 3 weeks.

 

[Peewee]

Ah k.
So its either going to be a faulty sensor, faulty piece of equipment, or broken wire.

Start with the basics.
Check you have +12v at both ignitors, and both coils.
Check block to -ve terminal resistance.
Check body to -ve terminal resistance.
Swap AFM's if you can get another one, same for ignitors.
Check you have spark on at least 4 plugs.
Check you have fuel.

 

[sleeperz]

are you losing injector pulse?

 

[Cobra]

One thing I have noticed is when I put a test lamp across the injector contacts and turn the ignition to on the test lamp illuminates. To my way of thinking this is incorrect.
Not knowing alot about the mechanics of the ECU, I would have thought this is not the way it should work. I would have thought the injectors would have become active once the ignition is turned to start. What controls the pulse of the injectors?

 

[Peewee]

Injectors are earthed through the ecu.
They have constant 12v while key is on.

 

[Lextreme II]

If AFM is the problem. The engine still runs, but it would shake like an earth quake.

 

[Peewee]

AFM turns on the fuel pump
If the fuel pump doesn't get its signal from the AFM, the fuel pump doesn't run
No fuel pump = dead car after 2 seconds

 

[Lextreme II]

I have few times run the engine with the AFM or MAF plug off. I forgot to plug it back when i start the engine. The engine ran but very rough and cant accelerate.

 

[Zuffen]

My car had the same symptoms lat time I wired the ECu in. The pump speed resistor was dead but I know Cobra doesn't run one.

I think Peewee is on the right track. AFM and associated wiring.

As for checking earths just check ever brown wire you can find with a multimeter . If one comes up with any unusual resistance clean it's earth point.

Brett if you need to borrow my AFM, igniters etc let me know. You may end up with my entire wiring loom! It's too cold to drive my car now so we may as well get yours going. I know your car is just as cold as mine to drive.

 

[Peewee]

I have few times run the engine with the AFM or MAF plug off. I forgot to plug it back when i start the engine. The engine ran but very rough and cant accelerate.

Hmmm, so obviously there must be enough pressure in the fuel lines to keep the motor running for more than a few seconds.
I dare say its running as lean as f*ck without the fuel pump going.

 

[sleeperz]

you can hook a 12v test lamp to batt positive/ point the neg side of injector with light/ crank to see if you get a pulse or flicker. if no signal from ecu (no pulse) the injectors will not open.

 

[Cobra]

I may of found the solution. After much trial and error over the weekend and after draining the battery from trying to start the car, I had to charge the battery.
Once the battery was charged the motor started straight away and ran for about 5 minutes and then stopped again.
Is it possible that the battery has a dodgy cell?
It is deceptive because the motor cranks over no problems.
The volts gauge is reading a good charging rate of 13.8.

 

[Peewee]

Simple test is to change battery with one from a good car.
Its unusual for a battery to drop a cell yet still be able to crank over 8 pistons @ 10:1 compression and turn 4 cams.

 

[Cobra]

10 PISTONS? Is there something your not telling us?