Dies at idle?????????

[ladenblowfish]

Hey guys. Before I go any further if the IAC or EGR were faulty, would either one of them always through a CEL on a gen 1? The recurring problem I am having is when I crank the car up, it will sputter for a second and finally die unless I keep giving it gas then it will stay cranked. Hot or cold. I've changed just about everthing over time. Plugs, wires, both coils, both o2's, crank sensor, cam sensor, cleaned MAF, several seafoam treatments. The car runs fantastic other than it shutting and cutting off every blue moon. I've check fuel pressure it stays steady at 35 at idle even when it tries to cut off. Now, the only thing I haven't replaced is the IAC or EGR because they are such a PITA on my 93. Could it be either one of them? I'm gonna change em both anyway. Oh yeah, no CEL at all. And of course I've searched first.

 

[wood_e]

Try this - remove the brake booster vacuum line - then start the car. If it keeps running your IAC is the culprit.

 

[ladenblowfish]

I just tried it and the car cranks and runs with the vac hose off.

 

[wood_e]

Try cleaning your IAC valve with brake cleaner.

 

[The Rev]

I know where the brake booster is. And by cleaning the iac do you mean to remove it? I hear thats a pita. I don't know where it is either, I took this pic looking to see if my throttle body was dirty, can you tell me where to look in ref. to this pic?

 

[Aquabrit]

http://www.lincolnvscadillac.com/attachment.php?attachmentid=29470&d=1191291216

You can also see the location of the TPS, opposite the IAC.

A faulty TPS can also cause the IAC to not operate, along with other troubles.

 

[The Rev]

Doesn't look easy/fun to replace.

 

[wood_e]

The TPS is easy - just remove the throttle body. The IAC needs to be removed to clean it.

 

[Roadboss]

Couple thoughts-

The real test on fuel pressure is not just at idle. Tape the gage to your windshield and have a passenger monitor the gage for you. You should not have it go below 35 lbs even at WOT.

Be sure your battery and charging system are up to snuff.

The problem you are having is a failed IAC and it needs to be replaced, there is no cleaning of it. Sometimes a good Seafoam treatment will correct the conditions that are similar as a faullty IAC, it may be worth a try.

Find a person with small hands and have them change it for you, I had to.

 

[wood_e]

I've cleaned quite a few Ford IAC valves with good results - it's worth a try. For checking WOT fuel pressure, pull the vac line to the FPR.

 

[AbrahamLincoln]

I've cleaned quite a few Ford IAC valves with good results - it's worth a try. For checking WOT fuel pressure, pull the vac line to the FPR.

how does pulling the vac line to the FPR help you test fuel pressure?

 

[kustomizingkid]

The fuel pressure regulator adjust pressure based off of vacuum... at WOT you car is pulling next to no vacuum so removing the line from the regulator simulates WOT....

 

[AbrahamLincoln]

but don't you only get an accurate reading with it under load?

 

[kustomizingkid]

Exactly... thats why the best thing to do is put the gauge on, tape it to the windshield and take it for a spin and see if the pressure really drops.