Ready to pull my hair out

[281pony]

ive got a nasty idle issue that i cannot fix for anything. here are my symptoms. ive been over the 25 point checklist once, im going off memory but im looking for some straight advice here.

at idle, it will start and idle good on cold starts. once you go to back up, or anything that causes the rpm's to drop/load the engine, the surging usually starts. it will surge from 500 to 1500 at low speeds/idle.

it always does it when your moving and push in the clutch. sometimes moving at speed, it surges higher into the rpm's. it will also be idling fine at a stop sign, then it raises from my 950 rpm idle, to 1300ish rpm, then drops down to 500 and starts surging without touching the throttle.

ive cleaned the hell out of my iac, tried another iac, timing is at 12, new tps, no codes except for the smog canister thats gone, manual transmission car, original mass air so i havent messed with the vss. think that covers the basics..

im on my girlfriends computer for the day, which it took 30 minutes to get on here. so searching for anything else is almost impossible.. help me out please.

 

[281pony]

here is some other stuff i remembered, and something it just did.

i get a howling/whistling in my upper intake sometimes. i pointed this to be the iac, because when pulling the plug off it, i got the same sound. plug it back in, and the sound continued? yet when idle was steady, i did NOT get this noise.

just a few minutes ago, it was puffing grey smoke at idle when surging. id rev it and no smoke. however, at idle, with the surging, i'd get puffs of smoke. then it steadied itself on the idle and it slowly cleared out the smoke.

i drove to the store and came back out. fired it up, let it get to a steady idle, no smoke. revved it, no smoke. then i drove it about 10 miles screwing with it to get the surging idle back. i could NOT get it to surge. i tried moving with clutch in, just barely letting out clutch and pushing it in, reverse, revving in neutral, revving while rolling, hammering on it and pushing in clutch, it ran perfect.

so i shut it off, started it right back up, and its surging again. while it was surging in neutral sitting there, i get a smell of oil and some white smoke blows past me. my mark8 fan always runs, so i couldnt see where it came from, but it was just one cloud that i could tell.

what the f? anyone have an idea here? driveability with this is fine except at extremely light throttle application, ive got a miss/bumpy feeling hesitation.

 

[tannerc91gt]

Same thing happened to me after a nitrous install, I replaced IAB, TPS, and checked gasket leaks, turned out I had fried the alternator, so don't look past that. Don't think it would cause the smoking though, but watch your gauges and watch the battery

 

[white 89 GT]

You still have water running into your EGR plate? could be a bad gasket.

 

[281pony]

egr has been deleted on this car.

something else weird happened. this morning going to work, the fuse popped for my mark8 fan. ive got it on all the time, fan relay is in the mail. anyways, i had no fan blowing. the car idled fine all the way here. i started it at break to go get fuses at work and it idled fine.

put in a new fuse, and with fan running, it surged a few times then caught itself..

so fan on is causing issues? i get good charge from my alt when driving. it dips a bit at idle with lights/stereo going. my intake is some bbk cold air crap. k&n in the fenderwell. so i dont see how the fan could cause it turbulance.

 

[dcurtis]

It could be the alternator how you are describing, basically with the lights and the radio alone fox alternators struggle, then you add on the electric fan and it will struggle that much more, I say alternator upgrade time.

 

[tannerc91gt]

That's what I'm sayin, I'm doin a 3g upgrade this weekend and from the sounds of it that's what you need to do too, goin from a 75a to a 130a will be night and day, and if it turns out not to be the cause of te surge, you won't have wasted money

 

[281pony]

had my battery and charging system tested. it checked out when it was idling normal. it idled normal quite abit today. still had some surging issues though, but less then normal now... even with my fan running.

950 cold cranking amps from my optima
13.9 volts at idle

i dont think my alt is the problem now. not sure what to think now.

 

[87GT40]

maybe there is an intermittent ground or short in a wire somewhere. try checking all terminals to make sure theyre all clean and tight. if it werent for the elec probs it was sounding like a vac leak. seems to happen a lot.

 

[281pony]

ill go over it this weekend i guess, but ive looked for vacuum leaks before. never found anything. i have a boost/vac gauge in the car, im getting good vacuum when it idles.

i dont know where to look anymore honestly.

 

[87GT40]

smoke machines help tofind those real pesky vac leaks. i think i have one and ive done the whole starting fluid thing around the intake and what not but still cant find it. im going to use a smoke machine to completely rule one out.

 

[Mustang78]

I vote alternator too.. 13.9v is ok but a little low... especially when a junkyard 3G can be done pretty cheap. I would unplug the fan when it surges next time and turn everything but the motor off. These are the reasons i prefer a carb, lol

 

[281pony]

ill give it a shot and report back.. one sec.

 

[281pony]

ok.. i started it again with a hot engine.

fire it up, light surging. let it idle for 20 seconds, it levels itself out. with fan on, lights on high, and stereo on.

shut it off, fire it back up, surging, i unplug fan and about 4 surge cycles later it levels out also.

here is the thing that is still concerning... the volt meter, buffers up to where it sits at. just now, it started registering one bar over the red, then it surged like 2-3 times, moved up one bar slowly, surged 2-3 more times, and it moved up another bar.

it generally sits one bar below the halfway marker, sometimes on the halfway marker should i replace alt?

 

[Mustang78]

it's a cheap enough upgrade.. i would just because you want to run a big stereo system, maybe it helps the surging and maybe not. At least you'll have a badass alternator to keep up the amps

 

[Dachipsta]

Yeah, I agree with everyone else. Your computer is freaking out with the voltage drop when all the stuff....fan..lights...stereo..are running. I had the same issue. I actually am having the same problem when its cold and I take off with the a/c on. That has the compressor, electric fan and inside blower running.....Bitch of it is I already have a 130 amp 3g alternator installed and it is still doing this crap.

 

[281pony]

i had the alternator tested yesterday. it was a shucks 80 amp replacement alt. it was putting out 5 amps at idle

so im figuring out what alt to replace it with now.

 

[jrichker]

The problem most people have when they see the "Surging Idle Checklist is that they just read through it. Some people never get out the tools and actually go through the list step by step. Step 5 of the checklist tells you to check the alternator and charging system...