Engine won't start. Too much fuel.
Thread Starter
Instructor
Joined: Mar 2003
Posts: 185
Likes: 0
From: West Sacramento CA
Engine won't start. Too much fuel.
Hey guys. I have an 88 and the engine is brand new. I finally solved the distributor and timing issue. My new issue is the engine will fire up but only if I hold my foot to the floor and only for a second or 2 and then it will die. I can smell fuel in the air big time. Even from the exhaust.
I have 40 lbs of fuel pressure and it is holding. There are no fuel leaks to speak of. The only conclusion I have to come to is that the injectors are dumping way too much fuel into the cylinders. I verified this by pulling a few spark plugs. The question is why? The system is in an open loop mode so the ECM should not be adjusting the fuel mixture at this point. Unless there is something going on with that Cold Start Valve.
Does anyone have any input on this one.
Thanks guys. :banghead:
I have 40 lbs of fuel pressure and it is holding. There are no fuel leaks to speak of. The only conclusion I have to come to is that the injectors are dumping way too much fuel into the cylinders. I verified this by pulling a few spark plugs. The question is why? The system is in an open loop mode so the ECM should not be adjusting the fuel mixture at this point. Unless there is something going on with that Cold Start Valve.
Does anyone have any input on this one.
Thanks guys. :banghead:
Race Director
Joined: Dec 2000
Posts: 17,551
Likes: 26
From: El Paso Texas
Re: Engine won't start. Too much fuel. (ciscokid)
OK, someone please correct me if I'm taking Cisco down the wrong road. Since it's a TPI, it can't be a single leaking injector if more than one plug is fouled. The odds of several injectors suddenly deciding to leak are...well...it doesn't happen. All sensors are connected, and assumed to be good. And in open loop, only the coolant temp sensor would control fuel mixture....everything else would run on presets. That leads me to a wiring/ECM problem. Doesn't the ECM fire the injectors by grounding them, thus completing the circuit? That being the case, if they were continually grounded, they would simply pour unlimited fuel into the intake port, correct? Now, what would cause this to happen?
Is there any chance that you have unintentionally grounded them somehow during the engine pull/reinstall? I'm thinking maybe a pinched wire or cluster of wires, maybe something got snagged and is grounding at least some of the injectors. Or something shorted out the ECM and fried it. With a regulated 40 psi of fuel pressure, it should start and run.
Is a faulty cold start valve possible?
This is where I would start looking. If I'm wrong here, hopefully someone will chime in and set you on the right course.
Is there any chance that you have unintentionally grounded them somehow during the engine pull/reinstall? I'm thinking maybe a pinched wire or cluster of wires, maybe something got snagged and is grounding at least some of the injectors. Or something shorted out the ECM and fried it. With a regulated 40 psi of fuel pressure, it should start and run.
Is a faulty cold start valve possible?
This is where I would start looking. If I'm wrong here, hopefully someone will chime in and set you on the right course.
Thread Starter
Instructor
Joined: Mar 2003
Posts: 185
Likes: 0
From: West Sacramento CA
Re: Engine won't start. Too much fuel. (Frizlefrak)
It could be the ECM. The current ECM has a new modified EPROM from TPIS. In fact the whole engine has been modified. I purchased all the parts from TPIS for the most part in terms of the major modifications. Tomorrow I am going to reinstall the OEM EPROM back in the ECM. If the excess fuel stops and the engine fires then the EPROM needs to be reburned. If that doesn't produce results, then I will disconnect the Cold Start Valve and see if that helps.
I appreciate your help. Thanks Frizlefrak.
I appreciate your help. Thanks Frizlefrak.
Thread Starter
Instructor
Joined: Mar 2003
Posts: 185
Likes: 0
From: West Sacramento CA
Re: Engine won't start. Too much fuel. (Frizlefrak)
I removed the modified PROM and reinstalled the OEM PROM (not an EPROM, my mistake) and low and behold no excess fuel! That engine started up and wanted to take off like a horse out of the starting gate. I will have to call TPIS and reorder another PROM. Because of all the mods I ordered from them they somehow thought that I was using larger injectors. That is all I can conclude. I get 5 burns on a new PROM. Thanks for all your help and input. I really appreciate the support. :smash: :cheers:
[Modified by ciscokid, 11:54 PM 4/12/2003]
[Modified by ciscokid, 11:54 PM 4/12/2003]
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Race Director
Joined: Dec 2000
Posts: 17,551
Likes: 26
From: El Paso Texas
Re: Engine won't start. Too much fuel. (ciscokid)
That engine started up and wanted to take off like a horse out of the starting gate.
[Modified by ciscokid, 11:54 PM 4/12/2003]
[Modified by ciscokid, 11:54 PM 4/12/2003]
Melting Slicks
Joined: Apr 2000
Posts: 2,408
Likes: 3
From: Bel Air Md
Re: Engine won't start. Too much fuel. (Frizlefrak)
You better check your oil for fuel. My computer went bad and did the same thing, strong odor of gas. It pumped gasoline, fouled the plugs and got into the oil. If the oil contains gas, you could have a motor/ bearing problem because of this. Cheap protection, change the oil
