I all i have a 89 2.8 replaced the tps set it to .57 or so replaced the iac and i still have a little rough idle when it warms up and a hesitation whether warmed up or cold what else could it be ..also i cant get my service light out either keeps giving me the code for the tps i have tried disconnecting the bat nothing works. what to do pulling my hair out. lol

 

Update... seems to be just a tad doggy off the line when it warms up but the hesitation is gone after it does warm up now but still idles just a little rough ....any ideas? light is still on too

 

Same problem here...'86 2.8L...I also cleaned the IAC. Whomever fixes it first, just post the results.

 

So you're saying you replaced the TPS and set it to the proper voltage...but, even after resetting the ECM, it still throws a TPS code? Now, did you disconnect the battery for a full 30 seconds? Try disconnecting the fuse labeled ECM instead.....it'd be a more surefire way to wipe it I think. But either way...I'd leave it for maybe a full minute just to be sure that it's had time for the computer to be COMPLETELY wiped. Ignoring the check engine light now... Does it ever stall?
Check your ignition components....spark plugs, plugwires, cap and rotor, and do a coil spark color test...if your ignition system is all good, then check your fuel filter to make sure you're getting enough fuel....they can clog up and kill your low end, make the car idle/run rougher, and cause deceleration stalls. Like mv did, clean your IAC valve as well..and do the throttle body and IAC passages while you're at it. Never hurts.

 

Brand new iac also it used to stall but when it did it would throw a 34 code (maf) then i changed the tps and that quit weird huh.. now i wonder if the maf is bad cause it used to throw that 34 code every now and then.. i disconnected the bat for like 10 mins should u disconnect the pos in instead of the neg? Also cleaned the throttle body when i had it off cause one of the bolts was busted off for the tps and i had to redrill and retap some people just never fix stuff leave it for others ,lol

 

Always disconnect the negative cable before the positive cable... it's a safety thing. The computer doesn't care either way; a disconnection from the battery = computer loses it's code memory.

 

ok tried the neg thing nothing i also tried the to do the iac like tech says f****** car wont even run with the plug unhooked unless i give it gas then it runs but as soon as i let off it dies ...what am i doing wrong/? also reset the tps to .62 volts still has a slight rough idle and a dead spot when you rev it right off the beginning but as soon as you get some r's its right there ...what gives man ?,lol still have 22 code the little sh** wont go away lol

 

Cant think of why the computer would throw a TPS code even when the TPS is calibrating or operating properly. So you set it right....did you check the TPS output at various throttle positions? Maybe it's out of whack and throwing a value that doesnt make sense somewhere in there. Try exchanging the part for another and see if that works. If the ECM is reset, the computer has no reason to throw a TPS code unless something IS wrong with the TPS.

 

yes i agree doesnt make sense .... i did try checking the tps at various places before and it worked fine ,but i didnt do that tonight...also why doesnt the car idle when i try to set the iac like the tech codes say to do it ,it just dies as soon as i let off the gas?I dont have another tps to try,, is the throttle suppose to touch the iac screw cause its not even close to it? maybe thats why i am getting a 22 code cause thats not set right? but i dont know how to do it if the car wont run

 

There isn't a screw for the IAC...it's just an idle stop screw...keeps the throttle blade at a minimum position basically. What are your idle rpms?

 

well my throttle isnt close to even touching it to regulate the rpms ...there about 600 or so in drive

 

What about out of gear..park or neutral...? 600 sounds about normal to me for being in gear with a warm idle.

 

hmmm probably 8 0r a little more its where it should be i think as far as that but its got just a tad rough idle and that flat spot right off idle but as soon as you get some r's its fine ....now this is when its in park and you rev it a little ..on the road its not as noticable but its still there and that fricking code too lol

 

I'd bet that there's something wrong with your TPS....faulty maybe. All this stuff just seems to point to that to me...and the code too. Try swapping them.

 

where am i gonna get another one my old one was broken from that bolt being broke off so there was no way to keep it tight and i dont know if the store will take it back hell its been a good couple of weeks now i have three other cars to drive so after i put that on and it dint work i left it sat and drove my truck :lol

another ? i posted in the cooling part about it running 220 down the highway that seems a little high to me its fine running around town and in traffic but not on the open road ? another puzzler for me and you lol

 

220 is too high for the highway...do you have an airdam? That's about normal I'd say for no airdam installed.

If you have the receipt for the place, exchange it. If you dont...give the part back to them in the original box and tell them it's faulty and you need another one..give them hell if they wont let you do it cause of the receipt...they'll probably just take it back and give you another one since you aren't asking for your money, just a new part

 

theres one on it yes just the little one that goes in the middle if thats it ...also the fan runs all the time too and it still gets that hot down the road ...not sure if i have the receipt was hell locating one had to call gm just to get a # for it no one carried it or stocked it for that yr then once i got the # gave it to the store and they ordered it thank *** my uncle used to work there so maybe i could get another one but they might say no too other than that as great power going down the road

 

An electric fan running all the time will burn the motor out.....at least I've heard this..I know mine sure died on me in a nasty way. Maybe your radiator is all crapped up, or you're low on coolant.

 

yeah i already lost the original one this one came off a camaro i dont know why it runs all the time the other one didnt? coolant is full but you know those two hoses on the throttle body that cools it them are basically kinked in half ...can you bypass those somehow...maybe thats why when your going down the road it just cant circulate enough and when ur in town the fan is on so it keeps it cool ?what do you think ?

 

For clarification....those hoses HEAT the throttle body... Their sole purpose of existing is for cold winters..to warm the throttle body and keep it from icing shut. Otherwise they'd be totally worthless and a terrible, terrible idea! Lol...

Dunno what effect a kinked one would have... So you're saying it runs COOLER in town than on the highway? Makes no sense at all dude...I have no idea what's up with that......

 

true but i dont plan on driving it in the winter its rust free now but yea they are both half closed off...you should check yours tomorrow and see if they look good or if there kinked too...yes i agree its a baffler man lol makes no sense at alll!!!! but i am thinking about bypassing them i read in the tech that they do it with the tuned port ones so why cant we with our 2.8's ?

 

We can do it. It's an arguable mod. Some claim to see very small power gains from it...but most dont. Most do it to make it more convenient to work in that area. I dont have my Camaro anymore so I can't look! See signature I'm posting below.

 

hey sorry to hear bout your camaro but gts are fast i used to have a 83 i am just thinking for cooling purposes for me ...you just tie the two together right? I have a 74 pontiac grandville 2 dr with a soon to be 400 hp + 464 in her its at the machine shop now hopefully in a couple of weeks i'll have her back