88 TBI runnin like crap!

ugh just today (as i needed the damn thing) my pos decides to run like CRAP. it's an 88 tbi 454 auto.
at first i thought the injector wires where givin me shit like normal. but fuel is flowing freely. it idles extremely high, over 1 to 1.2k and will idle back and forth from like 1k to 1.5k. it will also pull me at traffic lights when i come to a complete stop, the idle will pull me foward. it dosn't seem to miss or anything. what could cause this? it's not throwing a code or anything. throttle position sensor? map sensor? (im pretty sure this pile has a map sensor), or maybe a vaccume leak??? ideas anyone???? i hear someotherguy is on a roll for information. haha.

bump!!! common people help a brotha out!

sounds like a definate vacuum leak to me. the only other thing it could be is the tps on the fritz. try tapping on the tps while it is running and see if it clears up. spray some wd-40 around the base of the tbi and around vacuum lines. if it hits the leak she will rev up bro. just a couple of things to look for. keep us posted. later, brian

I'd be checking for vacuum leaks, sure. Don't overlook the IAC since it's just a computer-controlled vacuum leak. Could have a big chunk of carbon or crud not letting it seat.

Nothing binding up in your throttle cable?

Richard

pardon my newbness here, but wtf is an IAC? i have no idea what that is! lol. the throttle body it's self has 2 sensors on it, one is the TPS and behind that is some black box thingy that i donno wtf it does, then feeding off the back is the map sensor, and in the front is the egr valve and some kinda vaccume control unit. i unplugged that and replaced the map sensor and it seems to be running ok.

IAC = idle air control motor, it adds or removes air as needed to adjust the idle. It's that sucker sticking out of the side of the TBI that takes a huge wrench to remove it, 4 pin square connector on the end.

The part you're talking about with the EGR is almost surely the EGR solenoid, it should have 1 hose nipple on the front where it gets vacuum from the TBI, then what looks like 2 hose nipples on the back, people do get them mixed up or hook stuff up to them, but only 1 is actually a hose nipple - the one with barbs on it - is the hose to the EGR valve. The other one, with no barbs, should be left open, it's the vent.

Richard

^^^Tee-hee...he said, "nipple".^^^

it was nippular.

anyhow thanks for all the help. at leaste i can start lookin around and throwing sensors at this thing till it runs right i guess?

does it want to down shift when your driving

if your not finding any vacume leaks and your just going to go buy sensors start with the coolant temp sensor its the one under your thermostat it acts like a choke and its one of the cheepest

ur thinking of the blazer! my coolant temp sensor is on the side of the block, and i have a scanner that works on odb1 shit, i'll check tomarrow to make sure it goes into open loop mode. (or closed loop mode, i forget what one is good haha the book tells you) it's not throwing a code fyi