Car idles fine but cuts out half the time at a stop. Ideas?

[Pokageek]

I don't know why but my car seems to be cutting out when I come to a complete start. It goes into some kind of loop - one time - where the idle goes UP right after the complete stop and then goes LOW right after and it is enough to conk out. If I give it gas when it goes low then it stays running. Annoying.

 

[sKyZ]

Cracked throttle body gasket or idle air controller.. happened to me and was a bitch.

 

[MLC Stang]

Yup,

Sounds like a sticking IAC (Idle Air Controller).

Also, clean the "ring of gunk" that forms in your throttle body right where the butterfly valve seats in the bore. Over the years, a little ridge of dried on dirt (the ring of gunk I mentioned) forms there. When it builds up enough, it blocks the flow of air past the butterfly valve when it is closed at idle. You really have to remove the throttle body to get at it from both sides to get that ridge completely removed. The first time I did it, my idle problems went away. Now I do it once a year just for preventative maintenance.

 

[bjl95mustang]

Yah, pull off the throttle body and iac and give them a good cleaning. Then recheck the adjustments on the tb and iac. And it probably wont hurt to run a bottle of sea foam through your engine while you cleaning stuff.

 

[Pokageek]

How about a new TB? I should prob be running a 70mm anyway..Does this come with a new IAC? Or is the IAC a plastic thingy. Sorry for the dumb question. I just don't know much about TB in general.

 

[CManT1914]

Might as well get a new throttle body. No matter what some other guys say I noticed a little difference with mine. It won't come with the IAC or TPS though, you'll need to get yours off your old throttle body.

 

[Pokageek]

Might as well get a new throttle body. No matter what some other guys say I noticed a little difference with mine. It won't come with the IAC or TPS though, you'll need to get yours off your old throttle body.

Yes, but it is somewhere in the actual TB I think they are saying it is gummed up right? Those plastic connectors look just fine to me so I don't think they are part of the problem.

 

[CManT1914]

Yes, but it is somewhere in the actual TB I think they are saying it is gummed up right? Those plastic connectors look just fine to me so I don't think they are part of the problem.

Right, if you take off your intake pipe, then you can see in the throttle body, you'll see all kinds of grease and residue on the blade, and around the inside of it. This could be causing your idle problems. But you had asked if a new throttle body came with the tps and iac, and they don't, hence that's why I mentioned those two pieces. Oh, and those plastic connectors can "look just fine", but they are electrical sensors, so there's no way of telling if they are good or not by just looking at them. If you have a DMM (digital multimeter) and want to test them, let me know, I'll tell you how.

 

[Pokageek]

ok thanks!

 

[SeventyMach1]

Yes, but it is somewhere in the actual TB I think they are saying it is gummed up right? Those plastic connectors look just fine to me so I don't think they are part of the problem.

I think it is the IAC. It IS NOT an electrical connector you're looking for, though. The IAC is a valve.... fairly big in size. Can't miss it. It has 2 bolts holding it on. Take that off (careful not to mess the gasket up) and clean it out. (WD40 or something) However, one went bad in my truck and cleaning it did not help. I had to replace it. Are you getting any codes?

 

[Pokageek]

I think it is the IAC. It IS NOT an electrical connector you're looking for, though. The IAC is a valve.... fairly big in size. Can't miss it. It has 2 bolts holding it on. Take that off (careful not to mess the gasket up) and clean it out. (WD40 or something) However, one went bad in my truck and cleaning it did not help. I had to replace it. Are you getting any codes?

Thanks. Well no code check yet but this one does have (new engine though)146k miles and may be time 4 replacement if the cleaning doesn't workee. Anybody know where to buy one off the net? Thx.

 

[bjl95mustang]

The ford throttle bodys come with the iac and tps. Well, they use too.

 

[Pokageek]

The ford throttle bodys come with the iac and tps. Well, they use too.

Good idea. The largest FR TB for 94/95 is 65mm isn't that stock? or is 60mm stock? I like the idea of getting the new components though. [edit] I think someone mentioned stock was 56mm.

 

[Pokageek]

Bought the FR 65mm that comes with the new components. Out with the old and in with the new. Little by little guys!

 

[bjl95mustang]

they make 75mm tb for 94-95's

 

[SeventyMach1]

they make 75mm tb for 94-95's

Yeah, but I think he was wanting to replace the IAC & TPS as well, so he opted for a "complete" package. Let us know how it all works out.....

 

[nmcgrawj]

I have the same problem on my 351 that just got back together. 75% of the time it runs fine. But every once in a while when i come to a stop it throws the revs up to about 1800 and it dies instantly. I can "make" it happen if i have a little fun and "cut it loose" and get off of the gas...when i stop the motor stops. IAC? Its only a few months old.

 

[Pokageek]

All fixed! The new TB and included new electronics totally fixed it. Throttle respose is kick butt and idles/accelerates better in general. On top of that some moron in a ..couldn't tell. I think it was at least a new s class-500 but couldn't see the markings - tried to race me and I beat him both times low end and high end. He goes by and gives me the finger he was so mad he lost. I just gave him the thumbs down each time I pulled him and he swooped in behind. I think that's what po'd him. Guess he's not used to get'n beat, lol.

 

[wytstang]

Good to here and good kill.