car stutters after 20-30 minutes of driving

[lachachmtl]

mad: hi everyone ,i got a weird problem ,my car starts to stutter and hesitate after about 20-30 minutes of driving.

Before that,it runs fine.

no codes pop out on the scanner,no check engine light,no hose disconnected.it does that on all gears also between 3000 and 4000 approx.

2 mechanics said its misfireing.The fire cuts somewhere.we changed the spark plugs,wires ( wich i was sure wasnt gonna do anything ) then the crank sensor,coil pack,module and no change. the car misses between 3000 and 4000 rpm ,if you rev it more then 4000 it seems fine.

what else is there to check? the car starts good,no fuel pressure drop either.

ps ; whoever built this car,can you please open up a garage so we will at leats know 1 mechanic that knows how to fix it,cause everywhere i go and try to fix this car, no one knows what their really doing,just changing pieces left and right.

you could email me directly at lachachmtl@hotmail.com

passsed 3 long days at the garage so far, no problem solved yet :frown: :frown:

 

[Jerryl]

You may want to update your profile and add your location.
That way, you may be able to have someone point you to the right shop, or, help you get it resolved.

Edit:
Since the parts changes did not fix the issue, did you have the mechanic take the parts back off and not charge you for it?
How about not charging you at all since the issue is still there?

 

[UR50SLO]

Hey.. sorry your having trouble.

Sounds like a MAF problem.. be nice to watch a scan tool to see what it's reading when your driving.

Direct Scan would be able to record what's going on when it's screwing up. That's what I use on Stock systems to record and view.

Check the O2 volts when your having your hesitation/missing.

If a buddy has a good maf on his car swap it out and test drive.

If the problem does not exist when it's cold and does when it's hot it's

coming on in closed loop. (when the ECM rely's on sensors) instead of

program. Things to check:

TPS voltage all range to watch for cutout.
O2 volts .. and cross counts.
MAF readings idle/driving

That's a start... especialy if you've coverd the spark issues... (hopefully)

Double check the cam sensor.. take the cap off and inspect the gold ring inside that has a gap in it.. make sure it's tight. Inspect the inside of the cap.

That should keep you buizy for a evening :tongue:

E-mail me anytime
UR50SLO@aol.com

 

[lachachmtl]

JERRYL ,ok i updated my profile like you asked.

he didnt charge me for the coil pack and module,cause i told him,im not paying for that if it dosent solve the problem send it back.

i did pay for spark plugs and wires tough,wires that i got a speed shop instead of there.

i dont know about the crack sensor,it took him like 2 hours to take out so if idont pay for it i guess i will pay for the time wich is more then then sensor itself.i have to go back tommorow ,tuesday ,we ll see.

nothing comes out on the damn scanmaster,maybe we should go for a drive with the scanmaster plugged. i dont have a scan master so i have to go to the garage for that.

everytime my MAF or O2 sensor was at fault,a code came out,wich dosent now.but it dosent have the same symptoms tough.

i ll cvheck the cam sensor,grounds ,and again the scanmaster tommorow,ill make him check the voltage.

how much voltage should the sensors have?

 

[Geoff87]

Try swapping out the cam sensor.

Mine did the same thing at a lower RPM (1900-2100). I tried changing MAF's, ECM, coil, ignition, wires, plugs, and various sensors.

This went on for nearly 3 years (I hardly drove the car), then finally I changed the cam sensor and now the stutter is gone!....

 

[lachachmtl]

ok i ll try that

 

[UR50SLO]

Yep...

had alot of the same symtoms with cam sensors.

TPS should start in the .45 area to almost 5volts at WOT. Smooth transition when gas pedel is depressed (car off) key on, no glitch in voltage as it increases....

To watch the MAF you'll need to drive it and see if the voltage drops when your hesitation comes on or missing.

Read your plugs... Black and stooty or white??? all the same or two different?
If one or two are different than all the rest look into issues on those cyls.

O2's should be .750-800 WOT and steady driving and Idle vary alot depends on chip open loop/closed loop. but should have good cross counts lettting you know that it's sampling alot.

Get that far and see what happens... Find a GN buddy you can exchange parts with...

~Scott

 

[lachachmtl]

ok ,so today i changed the chip to the original one and still no change.

anyone have a solution here?

nothing as worked so far

 

[jretrodude]

Try this?

Try checking your cam sensor? Get the cam sensor tool and make sure it is where it is supposed to be. Also make sure the two screws are nice and tight on the cap of the cam sensor. Check your MAF numbers either on turbo link or scanmaster and make sure the number (at least at idle is around 5 to 6) Hope this helps. jretrodude

 

[Red Regal T]

While it may be any of the components suggested, I'd say swap on a known good coilpak/ignition module, and see if that fixes it. Same thing with the ECM, or try a different chip. Any part you can easily swap with a known good one from a friend's car, should make it easy to track down the bad part.

 

[lachachmtl]

i have tried all that it didnt work.

i didnt swap the ECM though