MINES STILL MISSING, PUT THE NEW COIL ON AND CHECKED THE PLUGS AND WIRES .. WENT FOR A TEST DRIVE AT MIDNITE 80 DEGREES OUT. STOMPED ON IT, FELT GREAT ALL THE WAY UP TO 5100 RPMS THEN IT STARTED MISSING AGAIN, NOTHINGS CHANGED, pleeeeeeeeeeease keep this post going so we can all figure this out . im still saving my money so i can take it to my dealerships service dept and pay them 4000hours to diagnose the problem and still be wrong (THATS ALL IVE BEEN ABLE TO DO????? HEHEHE

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94 T/A LT1 A4
FEW MODS,KINDA QUICK
MISSIN BAD!

 

If it does it in closed loop then I doubt its your injectors. I was referring to people that had the stumble as soon as they started the car.

I would start by disconnecting the MAF and seeing if all you guys still have the stumble. If you do then its not sensor related. If you don't, try swapping in someone else's MAF.

For now, the people that have the stumble as soon as they start up the car, swap in someone else's entire fuel rail and see what happens.

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'93 Camaro Z28 Automatic with a ZL1 hood.
No bottle.
No blower.
383 cubic inch serving of horsepower...hold the rice please.
Thats all you need to know.
ICQ: 23984221
Gripenfelter's Homepage

Disclaimer: The opinions expressed by me are not necessarily supported or indicative of the Government of Canada or any other Federal Employee.

 

I tried that . dicounected the maf and there was no change at all. Other than the SES LIGHT COMMING ON. I did notice that when i un pluged the tps the car would rev up and down from like 800-1100. And it did not stall out. when i plug it in the car drops back down to a few hundered rpms. and then alomost dies. It is a new tps. when it does this i look on the scanner and the fuel trim is going down to -40 . i have even seen on time that one bank had -15 and the other was positive 20...any ideas

 

ok i dont know much but what i do know is im having the same problem but only when my engine temp is around or above 190 degrees. I personally think that when im stopped the engine gets no cool air, its just sucking in hot air from under the hood, so like we all know once we get going it doesnt bog or hesitate, hot air equals no power, but the cooler the air equals more power, so hers my solutiopn and what im ordering, i went to www.thunderracing.com then went to the cooling section, i ordered a manual fan switch 160 degree hypertech t-stat and a bottle of redline watter wetter. i think this will fix it, cuz as long as my engine is around 180 degrees, it takes off like a beast. so good luck to you guys and to me. hope this helps.

 

I think too many of you are looking for "the fix" but the problem can be caused by many things. Since most symptoms are heat related, that leads me to guess that it's electronics or mechanical expansion. To suggest that it's "normal" is silly, because far too many of us have motors that USED to not do this, yet now the low rpm stumble.

I just put in a new Opti and while it runs much better than it did a few weeks ago, the stumble is still there. I'm going to try the coil relocation, new fuel filter, injector cleaner, clean battery terminals, and clean PCM connections. I have a hunch that the PCM connectors, much like computer board connectors, may need to be reconnected to brush off oxidation layers. Just a theory... I'll let you know how it goes.

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Hear LT1 cam WAVs, DIY head porting: members.***.net/gmarengo

'95, !CAGS, CAI, ForceII, Hooker Shorties, 14.2@103

 

I have read pretty much all 7 pages, but I won't say I am going through the same things as ALL of you.
The only problems I have noticed is that my idle bounces from 800 down to 400-500, and sometimes dies out. I also have a hard time getting the car started. It just doesn't turn over like it used to, but when it gets vstarted, it will stay running, no problems of it dying.
Anyways, I haven't changed my plugs in about 30,000 miles, my wires, my coil,my fuel filter, or ANYTHING else has NEVER been changed since I owned the car 33,000 miles ago (I know, I'm dumb), and I am going to do all of this stuff when I do my exhaust.

But I just cleaned my TB and MAF.I also used some STP "Complete Fuel System CLeaner" (Not the Fuel Injector Cleaner, the more expensive bottle-$12.00) with a full tank the other day, and I can honestly notice a BIG difference with how the car feels starting, driving, speeding, etc...
(I have also used the regular STP cleaner before and didn't notice **** with it)

As I said before, I AM NOT GOING THROUGH AS BIG OF PROBLEMS AS SOME OF YOU...
but it can't hurt to use some of this stuff.

Good luck, and wish me luck that I never have to use this thread as some info on this problem

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TONEZ28 - 97 Black Z28 A4 : 270rwhp/290rwtq
Mods : K&N CAI-Flowmaster-TB Bypass-Airfoil-160 Stat-Cutout-
!MAF Screen-Manual Fan Switch-TransGo Shift Kit-BFG DR's (track use only)
(373's, and Hooker LT's collecting dust)
Appearance : 01' z28 Chrome 5 Spokes- All GTS Blackouts-Billet Grill-
Orange Reflective z28 & Bowtie Overlays and Camaro Fill-in
Best E.T. : 13.64 @101.50 w/ 2.04 60'
w/ Drag Radials : 13.56@100.80 w/ 1.97 60'
http://www.andrenickatina.com/sfgi8nt

 

I have noticed a couple of things about the hesitation problem that my car has been doing.
First, sometimes it is worse than others. Meaning, sometimes the hesitation is totally obvious, and other times it barely does it.

Secondly, there have been a couple of times where it will be below 2000RPMs and I have just stabbed at the throttle, not expecting it to hesitate, and it will pop or backfire one time. It has only popped like 2 or 3 times now, but I know that it has something to do with the hesitation problem, because otherwise the car runs absolutely perfect. What would cause the single pop?
Timing?, fuel?, spark?, or a sensor?

 

I have the same problem. Pretty much all the ignition and fuel components are new. (well maybe less the ignition module and the fuel pump...)

 

well i just went out and bought a fuel presure checker and checked my fuel pressure..on my lunch break.it was fine. it stayed at 40psi even at wot. the only time it moved at all was when the car was reving down.So next is a check of the fuel injectors. There is 40 more dollars down the drain...

 

I have this problem too. It only happens when I am cruising or at a certain speed(above 40mph), and then when I slam the gas, it pops once (sounds JUST LIKE a backfire) and hesitates while it pops, and then goes.
I thought this was my TB being stuck after I cleaned it, so I cleaned it again and made sure to wipe EVERYTHING off, and it still happens!

I didn't see anybody say that had this problem in this thread. I guess I am in the "club"
So whats the fix? j/k

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TONEZ28 - 97 Black Z28 A4 : 270rwhp/290rwtq
Mods : K&N CAI-Flowmaster-TB Bypass-Airfoil-160 Stat-Cutout-
!MAF Screen-Manual Fan Switch-TransGo Shift Kit-BFG DR's (track use only)
(373's, and Hooker LT's collecting dust)
Appearance : 01' z28 Chrome 5 Spokes- All GTS Blackouts-Billet Grill-
Orange Reflective z28 & Bowtie Overlays and Camaro Fill-in
Best E.T. : 13.64 @101.50 w/ 2.04 60'
w/ Drag Radials : 13.56@100.80 w/ 1.97 60'
http://www.andrenickatina.com/sfgi8nt

 

Most likely that fix is tunning... that it pops once and then gets going... I had that same problem once... Could be also the type of GAP on the plugs and the need of a better coil.

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94B4C M6
Finishing project
Borla Competition--
AFR Heads
383 + Paxton Supercharger

 

MINE USED TO POP ONCE AT FIRST ACCELERATION IT WAS THE COMBO OF LOADING UP AT IDLE AND A SMALL LEAK IN MY INTAKE TUBE WEEEERD>
>>>>>>>>>>HEY GUYS IF I TRY TO UNPLUG MY MAF TO SEE IF IT STILL MISSES WILL THAT SET A CODE AND TURN ON THE ( SES ) LAMP?????

 

yes the ses light will come on!..

 

IS THER ANY THING ELSE I CAN TRY TO DO BEFORE TAKING MY CAR TO THE DEALER RE: MY OPTI COMPLAINT IM REALLY FED UP HERE, BUT PAYUING FOR SOMETHING THATS NOT IT IS GETTING OLD
......IS THERE ANY WAY TO TEST THE OPTI AND SEE IF THAT IS MY PROBLEM

 

well they say that all you havre to do is pull a plug wire and put a plug in it and let it ark to the block while just bumping the car over. do not start it. I have not done this yet I will try it this weekend.