Car stumbles/stutters/hesitates upon acceleration from dead stop or increasing speed sometimes

Tiny
RONBO1
  • MEMBER
  • 2003 CHEVROLET VENTURE
  • 75,000 MILES
New fuel filter, newplugs/wires/o2 sensor, dry gas, injector cleaner, no codes, certified mechanic found no misfires in computor history, 52psi gas pressure gauge reading engine off key on, 55psi at idle, 58/59psi on accelaration to say 50mph, even stumbles/hesitates at 58/59psi. Could it be coils? Fuel pressure regulator holds vacuum ok, sometimes it runs fine. Van has electronic egr. Depressing on accelerator when stumbling causes engine to perk up and car gets going. With brakes locked and gas pedal floored rpm changes by around 500rpm about.
Saturday, March 17th, 2012 AT 3:04 AM

9 Replies

Tiny
FIXITMR
  • MECHANIC
  • 9,990 POSTS
Very doubtful coils at fault since no misfires.
Was this
answer
helpful?
Yes
No
Saturday, March 17th, 2012 AT 4:01 AM
Tiny
FIXITMR
  • MECHANIC
  • 9,990 POSTS
Does it feel sound like misfiring or just loss of power?
Was this
answer
helpful?
Yes
No
Saturday, March 17th, 2012 AT 4:49 AM
Tiny
FIXITMR
  • MECHANIC
  • 9,990 POSTS
Needless to say, live data monitoring would help zero in on issue.
Was this
answer
helpful?
Yes
No
Saturday, March 17th, 2012 AT 5:11 AM
Tiny
RONBO1
  • MEMBER
  • 4 POSTS
Does not sound like misfire. Is loss of power. Surges up and down I would say about 4-500rpm approx it has no tach. We used to say it was "breaking up" when u get on the gas.
Was this
answer
helpful?
Yes
No
-1
Saturday, March 17th, 2012 AT 7:03 AM
Tiny
FIXITMR
  • MECHANIC
  • 9,990 POSTS
Live data monitoring would be advantageous. Wonder if auto chain stores can do that?
Was this
answer
helpful?
Yes
No
Sunday, March 18th, 2012 AT 6:42 PM
Tiny
RONBO1
  • MEMBER
  • 4 POSTS
I am giving up on it and dropped it off at the chevy dealer this evening. Hopefully I wont have to take out a second mortgage to pay them if they can find out the problem. Thanks for ur help.
Was this
answer
helpful?
Yes
No
Monday, March 19th, 2012 AT 1:04 AM
Tiny
FIXITMR
  • MECHANIC
  • 9,990 POSTS
Let us know how it goes.
Was this
answer
helpful?
Yes
No
Monday, March 19th, 2012 AT 8:05 AM
Tiny
RONBO1
  • MEMBER
  • 4 POSTS
Dealer says it s catalytic converter plugged wants 1300.00 bucks lolo takin to a mom and pops to see what he says.
Was this
answer
helpful?
Yes
No
Wednesday, March 21st, 2012 AT 2:26 AM
Tiny
CHEVYFORLIFE
  • MECHANIC
  • 33 POSTS
If it isnt a cat maybe look at a pressure control solenoid. Causing a shudder under load when hot. Pretty common problem with the transmission in your van.
Was this
answer
helpful?
Yes
No
Wednesday, April 4th, 2012 AT 2:08 PM

Please login or register to post a reply.

Sponsored links