Gents, I simply do not have this problem with 160,000 miles on the electrical components.

Opti is over a year old, with 40,000 kms, coil is 6 months old with 20,000 kms, NGK TR6 plugs, and MSD over the valve cover wires.

It sounds like one of the wires is grounding against the block, or associated metal. I simply will not stand for any kind of stupid "burp" in any system of my car, and running those wires over the top, has cured ALL for me.

Cam.
DR.ZED

 

dude. i got 3 sets of plug wires in my garage 1 OE 2 MSD all from within the last 10,000 miles, so im pretty sure that if OVC wires were the answer to this problem, this post wouldnt be 7 pages long! and we would all be sipping tea over in the appearence section!

thanks


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94 T/A LT1 A4
SOME MODS,KINDA QUICK
times- C-YA AT THE TRACK!!

 

Does you car seem slower?

Does it idle funny?

Does the oil pressure jump around or stay very low?

 

caR DOES SEAM A LITTLE SLUGGISH, like it likes to bog down(shift into 5th gear is what it feels like but its an A4) it seems like it has a little less torque out of the hole until 2000 then it goes crazy!,

its always idled great!

and the oil pressure has always jumped around. and it runs at idle about 20 lbs if i can remember correctly then 40 or so when cruising..

what are you thinking? thanks

HH

 

If your oil pressure is jumping around at idle without you touching the gas when the car is hot then it would be an internal engine problem.

Same for the car being sluggish.

But if the car is taking off above 2000rpm and sluggish below that it might be clogged injectors, fuel rail, or fuel regulator. That wouldn't show up on a fuel psi guage.

Swap in someone else's complete fuel rail and injectors.

[This message has been edited by Gripenfelter (edited August 15, 2002).]

 

already swapped all that out before, no help and the pressure just jumps around as u get on the gas and off the gas (real sensitive) like a tach!

 

Heath, tea at 3pm?

Anybody tried a test with the MAF unplugged running in speed density mode?

What about running the car in field test mode? (car stays in open loop).

This would eliminate the O2 issue, and the majority of the PCM BLM issues.

I tried field test mode once, and the check engine light flashes when you're in it. I don't remember the jumper settings now, but it involves jumping two pins on the diagnostic connector.

I can confirm later tonight.

Cam.
DR.ZED

 

speed density i did that when i installed the vortech elbow and nothing changed. tell me more about this feild test mode? is it something i should try? my 02s arent a question any more,and my car barely does it in the morning upon initial startup?(open loop)

brian would u like any lemon or sweetener??

 

Its at home in my shop manual.

Will bounce on later tonight with it.

Cam.
DR.ZED

 

I am having the same miss at about 5k rpms. I have replaced the opti, plugs,intake manifold gasket all to no avail. I have another weird symptom that may help you guys figure out my problem. When its damp out (like after it has been raining), the car does not want to start right away. It cranks for about 8 seconds then finally turns over (sometimes it doesnt start and I leave it for a while). If anyone has an idea of what would help me it would be much appreciated. I hope everyone gets their problems solved.
Chris

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1995 Z28 M6- flowmaster -G2 CAI- Granatelli MAF- LT4 KM - Nitto DR's- best 1/4 mile E.T. :13.7 @97mph ---1987 2.8 Camaro (Mullet edition beater)---1987 Yamaha XT 350

 

To anybody who wants to know about Field Service Mode.

Short the top right pins together (94 cars), or the serial and ground together (95 cars), to enter field service mode.

With the car on but not running, shorting these two will energize all the solenoids in the engine, which helps for diagnosing those that only come on normally when the car is running.

With the engine on, shorting these two leads enters the car into Field Service mode, where no new codes are learned, and in closed loop the check engine light flash durations are slower, than when the car reaches closed loop. In this mode, the check engine light will be flashing at all times. Quicker for closed loop, slower for open loop.

No new codes or BLMs are learned.

I'd reset the PCM, then try this mode. If it helps, then it sounds like feedback from the O2s and exhaust issues may be the cause, effecting the BLMs.

Let me know how this goes.

Cam.
DR.ZED

 

Curious about the speed density mode check. I have not done this recently, but I am certain that my car will not run with the MAF unplugged. If memory serves me, it will almost start, fire a little and then die. Is it supposed to be able to run w/o the MAF? If it will not what does this mean??

Bill H

 

Haven't gone back through this entire thread, but I saw in a tech column in one of my mags where a mechanic had this same problem, miss at high RPM, turned out to be moisture collecting in the MAF, and causing it to read incorrectly. He said he had seen this on more than one LT1 car. I'll look around and find that article... Have you tried borrowing a MAF and running it?
------------------
Texlurch - 68 Camaro-LT1 w/Hot Cam, TT & TIC coming soon!
" a little spray never hurt anyone, spank you very much!"
or the old standby:"I came here to race, not sell real estate. You ain't scared, is ya?"

[This message has been edited by texlurch (edited August 17, 2002).]

 

OK, let me see if I can condense this, as per this mechanic " I have seen this on numerous LT1 cars, a high rpm perfomance issue. A moisture contaminated MAF sensor, sometimes caused by the electric AIR pump. During cold start, moisture from the exhaust system is trapped both in the AIR pump, and in the air intake box before the MAF. This moisture tends to settle on the "hot wire" or sensor element of the MAF. It then gravitates to the bottom, where the wiring harness and "brain" is located. This condition will greatly affect the sensitivity of the MAF, and hinder it's accuracy at higher rpm's. It is possible to clean the contamination off the hot wire with isopropyl alcohol, do not use carb or brake cleaner as it leaves an oily residue. Depending on the severity or the contamination, the MAF may need replaced, and the pollution system evaluted"

Sounds like he knows what he is talking about..
By the way, I had my plug/wire connector on my MAF on both my 97 T/A and my 99 Z71 turned to the top, and never had this problem.. but who knows? It would be interesting to know the orientation of everyones MAF connector that is having this problem, and those that aren't.
Worth a try.

------------------
Texlurch - 68 Camaro-LT1 w/Hot Cam, TT & TIC coming soon!
" a little spray never hurt anyone, spank you very much!"
or the old standby:"I came here to race, not sell real estate. You ain't scared, is ya?"

[This message has been edited by texlurch (edited August 17, 2002).]

 

I was wondering if you were running the 180 Thermostat?Only because if the temps don't get high enough,then then computer can't go to closed loop.(Spelling check?)Maybe some info from one of the sensors is telling the computer to back off.Hope this helps.(Haynes manual).My02

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93 Formula,98,000mi,cold air,msd 8.5,ngk tr55's,A4 firestone firehawks sz50ep's high flow cat,flowmaster 3 chamber, quakerstate high performance 10-30 ac delco oil filter, 180 thermo,le bellows,tb bypass,gm coil,red with chrome wheels.