whats up with my idle?
 

I just removed my smog pump, and all associated tubing from my 93 gt. Plugged the holes in the back of the heads as well. It has a h pipe too. Now when ever I start the car I have to rev it up once or twice and then it will idle very ruff for about 45 seconds and then it smooths out and idles fine. If I don't rev it up at first it dies. Has any body had this problem? I dont get a check engine light but I did pull an 85 in KOEO and an 34 and 44 in KOER. Any help would be greatly appreciated.

Well I have a pretty good idle bug in mty car as well, and I have HEARD from a few people that disconnecting the smog pump and lower egr hoses will cause a slight idle roughness. Can anyone else back that up?

The roughness I have is almost like a missfire, its ROUGH. The wierd thing is it goes away and it runs like it did before the mods after about 45 seconds. I puzzled but I havent worked on trying to fix it very hard yet, I'm in the middle of painting it.


Anybody have any ideas?

What is up man. Where at in evansville are you from...i go to school out at usi and work in eville and live in hendo. Me and my friends have a club called R.P.M. Racing and would like to meet you or something. I am an ase certified mechanic....i have 5 fox bodies and one of them has none of that smog **** on it. Your problem is most likely the IAC(idle air control motor) or the egr valve and sensor. If you would like you can email me at Dragula90lx@hotmail.com and maybe we can meet up and i can take a look at it or something. I do have my own garage and between the group there is like 15-20 stangs of every year!!! Well, hope to hear from you.

problem?, what problem?
 

IMO, if you can start your car, and it runs fine after 45 seconds and a few flat revs, there IS NO PROBLEM.............!

Jay

No, there is a problem.....either the IAC or the EGR valve is sticking because of carbon. The only other thing is the EGR motor on the back of it and they go bad sometimes, but if they go bad, it runs like crap all the time. You need to talk both of those things off and clean them thoroughly with parts cleaner.

If the IAC is bad or the EGR is sticking wouldn't the car have run like crap BEFORE the smog elimination???????????

And he states it runs like a champ after ONLY 45 seconds, AFTER the smog elimination.........sounds like the IAC and EGR are fine to me??????

Eliminating that pump just richened the crap out of that car, especially if it's stock or near stock.

No, when he removed the smog pump and blocked off the back of the heads it blocks off the flow passage to the egr.....fine good point, the iac is fine, BUT the egr is getting all the crap that is breaking loose in the intake from the sudden boost of pressure caused by the bypass of those back ports. It will not run rich if you remove the smog pump, the only thing it does is pump fresh air in the exhaust to mix with the excess hydrocarbons for the converters to burn so less unburnt fuel is released into the atmosphere, therefore passing those damn emissions tests.

John Morgan
ASE Master Certified
R.P.M. Racing Performance and Body Repair

You know i am not trying to argue with anyone and not getting sh*tty....just having a discussion, don't want to make anyone mad.

Me either......
 

No dude, I'm not arguing either, always a pleasure hearing from an ASE certified wrench, I respect that, I took the test twice working for AUTOSTONED!, good scores, but I never "passed", boo hoo!

I ran bone stock heads, cam and intake into the mid 12's N/A and never did that EGR or Smog elimination as I had emmission test where I lived. Over the years I've had 9 5.0 Fox buckets, ranging from bone stock to very low 11's, ALL naturally aspirated, so i have a bit of experience to.....to me though again, any modded 5.0 that runs fine after 45 seconds is running GREAT!!!!!!!!!, hehehehehehe!!!!!!!!!........Would you agree that without the Oxygen content added by the air pump "HELPS" the 02 sensors achieve 14.7:1 Stoich???????without that air, those old 02's gotta be taxed big time...........maybe 02's are contributing to sloppy driveability, you know how INACCURATE they get after 50,000 miles, very important piece wouldn't you agree?

Again, to me, 45 seconds of rough is okay with me.

Jay

Jay

Well you know i would agree to the air pump feeding oxygen to the sensors, BUT the air pump is fed into the h-pipe about 3 feet down stream of them and never gets near them.....Yeah, i'll put you on my aol instant messenger list, we can chat some car **** sometime....!

Well I tried cleaning out the EGR valve thinking it was stuck... It was really nasty but it operates fine. I timed how long it takes it to smooth out. Its about 95 seconds everytime. After 95 seconds it smooths out almost instantly, and then wont do it again until I shut the car off and start it back up. I doubt its the O2 sensors because they just fine tune the air/fuel mix and they dont even have 10k miles on them. Steedagt90 I'll send you an email.

My 90gt did the same thing, when it would start up after sittin overnight or a few hours I would have to rev it as soon as it starts to keep it goin if I didnt the RPMs would just drop and the car would stall, I have my smog pump still attached and noticed a hose coming from it had a burn hole in it from my headers so I fixed the hose and now it will start right up. Just my .02

I was just going to create a new post until I read this one first.
I have an '88GT that is bone stock and I must rev it a few times before it will idle ok.
Do you think it's either my IAC or EGR since my engine is entirely stock?

I'm gonna take a look at the IAC and see if it needs to be cleaned Friday afternoon.

I think you have a vacuum leak(s) somewhere. Was that Code 85 an on-demand or continuous code (first set or second set)??? Did you just disconnect the EVP or is it faulty? Here's what I have:

Code 34 - Insufficient EGR flow/excessive exhaust backpressure.
Code 44 - Secondary air injection system inoperative (right side).
Code 85 - If continuous: adaptive fuel lean limit reached. If on-demand or running: canister purge circuit failure.

I'd try plugging vacuum lines one at a time and try starting it after each attempt to see if it made a difference. You've got a few things going against you, but take your time and do things logically. You'll figure it out.

Problem solved. It was a vacuum leak. Now if I can finnish painting it in the next couple of months, I'll be happy. Thanks for the help