Idle Hanging

[DriverSideImpact]

High Idle

My 1996 2.3L has had a strange idle problem for a while, mainly just this winter...so I guess when its cold out. It will hang up high, around 1500-2000rpm, in between shifts and when at a stop. Once I'm totally at a standstill, if I engage the clutch a little bit, the idle will drop back down and stay there. It's rather annoying and it messes with my shifting. Another thing I've noticed is there is a rather large lag if you blip the throttle.

So I have been searching around for causes of this and I can't find anything. The PO put in a new Idle Air Control on. I recently put in a Throttle Position Sensor. Some of the vacuum/air tubes off the the intake tube, throttle body, and valve cover had been taken off by the PO, but I made sure those holes were plugged and the valve cover has a little breather filter on it. There's no check engine light, no trouble codes, and it passed state emissions a few weeks ago.

I'm not sure what too look at next, or what to look for. Ideas? Suggestions?

 

[DriverSideImpact]

**Update/other details--I also noticed that the idle once in a while drops real low (below 500rpm). There are other times where the idle drops off real low between shifts.

Ideas anyone?

 

[DriverSideImpact]

That's cool. No one has any ideas at all?

 

[bp50]

Possible Vacuum leak, check what codes come up!

 

[tcranger]

hey you said you replaced the tps. is it the adjustable tps and if so is it adjusted properly? i had a problem with my truck right after i put a turbo coupe motor in mine idling real high and then i could load the clutch a little and it would go away for a bit.

 

[DriverSideImpact]

Like I said, there are no codes. And the TPS looked all self-contained. plus this issue was happening before I replaced the TPS.

 

[lordkyleofearth]

Have you cleaned the throttle body and MAF? I had a 91 integra that did similar...

 

[modelageek]

My 1996 2.3L has had a strange idle problem for a while, mainly just this winter...so I guess when its cold out. It will hang up high, around 1500-2000rpm, in between shifts and when at a stop. Once I'm totally at a standstill, if I engage the clutch a little bit, the idle will drop back down and stay there. It's rather annoying and it messes with my shifting. Another thing I've noticed is there is a rather large lag if you blip the throttle.

So I have been searching around for causes of this and I can't find anything. The PO put in a new Idle Air Control on. I recently put in a Throttle Position Sensor. Some of the vacuum/air tubes off the the intake tube, throttle body, and valve cover had been taken off by the PO, but I made sure those holes were plugged and the valve cover has a little breather filter on it. There's no check engine light, no trouble codes, and it passed state emissions a few weeks ago.

I'm not sure what too look at next, or what to look for. Ideas? Suggestions?

has the thing run right since you got it from the PO?

 

[modelageek]

I am confused......the PO pulled vacuum lines and "stuff" of and now it runs bad?.....i think you need to get some vacuum tubing and pvc hose etc......and put the stuff back?..IMHO..........how come the ford engineers did not think of pulling that crap off......

 

[modelageek]

That's cool. No one has any ideas at all?

I think the reason no one responding for 8 days is because we mostly know about trucks that are stock.......when you start pulling vacuum lines off etc.......it is near impossible to figure out what the issue is...IMHO...I am sure there are plenty of peeps that will help if you want to run it stock..

 

[DriverSideImpact]

Well, as far as I know, the only things he pulled off were the lines from the valve cover to the intake tube (PCV stuff I assume). I haven't found anything else missing/plugged. It ran ok when I got it, but he said he had been chasing a little idle problem. And he had fixed some things, like the IAC (i'd have to check the records he gave me to see what else he all had replaced/fixed). When I test drove it, it idled high, but he just didnt have the throttle adjusted right after he put in the most recent new parts.

I haven't cleaned the MAF. Maybe I'll clean the MAF (I have electrical spray cleaner somewhere) and do the TB too.

 

[bp50]

With the breather filter on the valve cover, you're pulling unmeasured air into the engine witch is creating a VACUUM LEAK, unless the pcv system has been blocked off.

 

[Notch]

With the breather filter on the valve cover, you're pulling unmeasured air into the engine witch is creating a VACUUM LEAK, unless the pcv system has been blocked off.

Having a breather on the valve cover is not going to cause an unmetered vacuum leak. All it will do is provide crankcase ventilation. An unmetered vacuum leak would be caused by a direct atmospheric leak between the throttle body and the valve.

 

[Bryan22]

I would start with 2 things, one is check for vacuum leaks. Seconds, i wouldn't assume the IAC valve is good just because it's new.

 

[DriverSideImpact]

I have the breather filter on the valve cover and the hole in the intake tube is plugged up tight. So there isn't unmetered air being sucked into the intake. I hate checking for vacuum leaks. I might check with the local high school auto shop. I think they have a vac-leak smoke tester

Any way to test the IAC?