RotorBalls

This problem probably started 6 months ago or more. While at cruising speeds on the interstate for example with very little pressure on the accelerator pedal the car would start to jerk or buck. Give it some gas or let off and it's fine. I changed out the fuel filter and plugs and it seemed to help for maybe a couple months and it started doing it again. I ignored the problem for months and while driving home the other day it got 100 x worse and does it no matter how much gas you give it it will buck but it still starts up fine and will run. It's idling poorly as well and will stall.
I'm not very good at troubleshooting car issues and plan to take it in to get fixed but would love to be able to fix it myself if I can. I've been told it's possibly the TPS. If this is the problem I think I can install one but I don't know how to adjust the TPS properly if this is needed. Will need details on how to do this if the TPS isn't preset.
Thanks in advance if anyone can help

ocjmakaveli

how many miles are on teh car?

how are the rpms? do they fluctuate up and down? is it at 800 or lower in idle?


basically does it stall or it wants to? try the Idle air control valve if its idling bad the valve could stay closed or open regardless giving you problems.

recently i had some bad idling issues the car would be revved way too high and it turned out to be both my iac and map sensor i got them from a local junkyard for less than 10 bucks i actually got a couple just in case.

The important thing is to reset the ecm by taking out the fuse after replacing parts so that the idle is recalibrated.

RotorBalls

Car has 115k on it

Idle was pretty solid before maybe some surging once in a while. But now that it's acting up it will stall at any given time and goes up and down.

RotorBalls

replaced the TPS, that didn't help. Not sure what the valve is above the TPS but I took that off and cleaned it also. I'm thinkin maybe injectors. Gonna run some cleaner in it for a while. Any other ideas? Where's the iac at, is that what I cleaned?

meuhus

i have a 91 similar problems
had a bad injector
id look there

RotorBalls

I'll look into replacing them. Hope they're not too expensive. Maybe find some used in the yard.

meuhus

if you don't want to buy new and you have time to let the car sit
check them first with an ohm meter
if you find a bad one
(ohms should be around 12 i think its 11.8 to 13.something autozone knows what they should be, any above or below are bad i guess my bad one was 2.2 ohms)
any way
check out injectors4u.com i got some from them
17.00 each plus shipping 105 for all 6 including shipping
they are reconditioned better than the bone yard and i'll bet the same price
they are working great in my car so far
if you do find a bad one
i've been told to replace them all
you have to take them all out any way
and this way you won't have to do it again
as the others start to go bad

RotorBalls

I don't know to test them with an ohm meter exactly, though I suppose I could look it up. I think my multimeter is broke though or the wires on it are bad. Guess I could replace those too while I'm at it lol.
Since you've done this, will I need any other gaskets other than the one for upper intake manifold/plenum?

meuhus

i replace my upper plemun gaskets
(the old ones still looked good 14.00 autozone)
depending on how u take it apart
u'll need to remove egr valve (i just replaced one of those gaskets for it because one came off tough)
if you don't remove the coolant lines running to your throtle body you'll have to remove the throtle body from plemun
should replace that gasket
o ring for the fuel lines should be replaced and if you get the injectors for injectors4u they come with new o rings
i think that is it
the line for the pcv valve is under the plenum goes to rear valve cover
that is a preformed hose thing from gm i broke mine to pieces
on removal so becafull of that may need a new one of those
i just used emmission hose or what ever they gave me a z
that is about it i think
take your time
good luck

RotorBalls

pretty cheap injectors at injectors4u but did you have problems contacting them? I wanted to check on shipping prices and they're impossible to get a hold of. I suppose I could paypal a few extra dollars based of your post. They don't specify shipping costs anywhere from what I could see. Wanted to know what overnighting would cost so I could have them by the weekend.

meuhus

it took 2 days thru the mail
he is in michigan i am in illinois
for $10.00

fill out there contact form and ask them what it would be for over night
i think he e-mail me a shipping price list but i deleted it all ready

RotorBalls

Yeah it was speedy priority shipping. I got my injectors on saturday and started to get to work. Needed some gaskets still so I stopped for the day when I got down to the fuel rails. I'm having some difficutly getting them out though. I wanted to finish the job up on sunday but got rained out so I'm hoping to finish tonight

Is there a trick to getting the fuel rails out? I removed the two hex screws on the fuel pressure regulator bracket and the four that hold the fuel rails down but I can't seem to get them pulled apart because of the FPR in the way. I got a lil frustrated and just pulled really hard on one side and got a couple of the injectors freed from their holes but the one closest to the fpr is still in and I can't seem to get enough slack to get it out. Anyway to remove the fpr to give the fuel rails room to be pulled?

Thanks for all the help by the way. I hope this is the fix. It seemed like the car ran a little better but still shitty after driving it a few days with injector cleaner in the tank so I'm hoping this will do the trick.

meuhus

i had a hell of a time with mine
i pulled and rocked like the manual said but couldn't get them out like that

i had to take off the injector clips on the fuel rails i didn't sperate the rails from fpr and then removed the fuel rails from the injectors
as an assembly

then i had to use pliers on 5 of the injectors to get them out
only one came out by pulling with my hand

i grabed onto the electrical connector part of the injecetor
with the pliers it kind of chewed up the ears for clip on electrical connector but couldn't see any major damage

my intake was dirty and i think the oring were stuck to manifold
i tried to vacuum of manifold best i could
then pulled out injectors
maybe try soaking the area around injector w/ wd-40
to help loosen them up

it goes back together easy because you put oil on the o-rings
and the hole thing just slides back into place

hope this helps

RotorBalls

Yeah I pulled the injector clips too thinking I'd be able to free the injectors from the rails but they're in there pretty good. I guess I'll keep working at the fuel rails. I was afraid I'd break something by rocking or pulling too hard or in the wrong direction. So I guess I didn't need unscrew the fpr screws but I thought it might help. I'm sure I'll get it done tonight though.

Oh one last thing, unfortunately one of the injectors was missing one of the smaller o-rings. I bought a set of o-rings from napa for my injectors but they were both the same size rather than one smaller/bigger. I'm concerned I might end up with leaky injector with this looser fitting oring on the end. It fits on there but just doesn't seem as snug as the ones on the others. I'll check for leaks after I get them in but it's just my luck I'd get one with a missing o-ring. I was gonna email to get one sent but I don't want to have to wait two more days for it to come.

RotorBalls

I wanted so bad for the injectors to be the fix. I started her up tonight and it started knocking like I left something in it. Scared the shit out of me but I know I was extra cautious taping intake holes and everything shut. That went away after a minute and a few revs.

Took it for a drive and I thought it might be fixed but once it got warmed up it was back to the same ol sputtering and stalling while idle. What else is there to replace, fuel pump? I've gone more than a week without a car and I'm thinking I might just take it in somewhere now

Oh and I never got a check engine light until tonight. As I was parking the car back at the garage the light came on. I turned the ignition off and started it back up and the light was still on, and then momments later turned off. Can a place like autozone which does error code reading still get a reading on a check engine light even though it's not on? Was hoping maybe they could check it and get a reading on the last thing that tripped the check engine.