GhostRider_fr

Hi there !

My 1988 Iroc had been workin' fine for the past few months, but I have a problem right now.

When I turn the ingition key to the on position, I can hear all the relays working fine, but I can also hear another strange noise, which reminds me about the noise that fuel injectors make when they're operating.

So I did put my hand on the fuel rail, and I could feel through my hand that the injectors were working erraticaly.

If I try to crank the engine, I have to be at full throttle in order to clear what seems to be a huge amount of fuel in the intake (and there is a heavy gasoline smell at the same time) in order to make the engine start... when it starts...

If it starts, it will run on 6 or 7 cylinders for one or two minutes (in the best case), and then it shuts down by itself...

The fact that I could hear the injectors working BEFORE i did crank the engine make me think about a defective ECM, but as you know these cars better than we do in Europe, I wanted an "Over The Pond" advice

Thanks for your help, and sorry for my poor english, as it's not my natural language.

Pierre
DINARD - France

TransAM Joe

iTrader: (6)

Sounds like injectors have gone south, but to check get a multi meter and measure the resistence across the two terminals, should be around 14. If below 12 I would consider having them rebuilt or replaced.

GhostRider_fr

Thanks, will check tomorrow.

However, can only one defective injector make all the injectors fail ?

Maybe due to the fact that the L98 injection is not of a sequential type ?

GhostRider_fr

Well, I've measured the resistance of my 8 injectors : goin' from 16 to 18 ohms.

The shop manual says the resistance must be over 10 ohms, so I think the injectors are okay.

I've tried something else today :

I've disconnected the MAF and the coolant sensor connectors, and I tried to crank the engine. The engine starts, but it runs a bit roughly, and the mixture seems to be very rich, as it smokes black at the exhaust, as if I had a diesel engine under the hood.

I then reconnected the MAF, and left the coolant sensor disconnected, and tried to start the engine once again : It then runs perfectly, so I think that the problem might come from on of my sensors.

Can't say if the problem comes from the coolant sensor, as the engine is running under the open loop mode, but I think that I should try to change this sensor first.

The guys at www.camaro-firebird.com (french message board concerning F-Bodies) told me that the injector noise I heard could have come from the Cold Start Injector : As the ECM might see a bad temperature due to a non-working Coolant Sensor, it could try to enrich the mixture via the cold start injector.

Next things to do :

I have to find the resistance values of the coolant sensor in the shop manual to test it at different temperatures.

I also have to check if the Cold Start Injector Switch (located next to the Coolant Sensor) if working properly : Got to find a procedure to test this stuff in the Shop Manual.

Has anybody got another idea ?

GhostRider_fr

Well, I've tried with another ECM that a friend lent me, and it worked well, so I ordered a reman. ECM at rockauto to fix my problem definitely