'86 stumble on hard acceleration
Thread Starter
Instructor
Joined: Jul 2005
Posts: 228
Likes: 13
'86 stumble on hard acceleration
My '86 auto runs fairly well most of the time. If I nail the throttle from a standstill or lay into it hard from a roll, there is a big hesistation or stumble where the car pauses (almost seeming to stall) before the Vette takes off. Its mostly stock except for a clean K&N filter, Dynomax Super Turbos and cat-less front y-pipe with a new O2 sensor. Any ideas on what to check on? Thanks.
Team Owner
Joined: Jan 2003
Posts: 20,324
Likes: 249
From: Summerland B.C. Canada
I would start with testing fuel pressure under load. That would require a gauge with a hose long enough to reach the windshield, so you can monitor it.
Has your fuel filter been replaced lately ?
Was the fuel at 1/4 tank or less ?
Any SES light or stored codes ?
Has your fuel filter been replaced lately ?
Was the fuel at 1/4 tank or less ?
Any SES light or stored codes ?
Thread Starter
Instructor
Joined: Jul 2005
Posts: 228
Likes: 13
While the filter doesn't have many "miles" on it, it has been on there awhile as the car doesn't see alot of roadtime (that's about to change 
). I'll toss a new one one and check the fuel pressure as you suggested. There aren't any codes. Thanks.
). I'll toss a new one one and check the fuel pressure as you suggested. There aren't any codes. Thanks.
1st Gear
Joined: Mar 2013
Posts: 1
Likes: 0
I had the same problem recently. The check engine light was on and the car would hesitate just a second when I hit the pedal to the floor. The problem ended up being with the throttle position sensor constantly reading WOT.
