Engine misfire on acceleration!
Thread Starter
Le Mans Master
Joined: Nov 2009
Posts: 6,119
Likes: 156
From: Huntington tx
Engine misfire on acceleration!
Just started a week or two ago, would misfire under acceleration but when the pedal was released and applied again it would be fine. This started ever so often, not consistently. But it now happens more frequently, still depends on how hard the gas pedal is applied and reapplied.
No codes, no vacuum leaks, maybe Throttle position sensor?
Has anyone ran into this before?
No codes, no vacuum leaks, maybe Throttle position sensor?
Has anyone ran into this before?
Last edited by sfc rick; Oct 2, 2011 at 04:23 PM.
Team Owner
Joined: May 2001
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From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
Carefully follow your injector wiring harness (both sides) where they go to the rear of the manifold and makes a turn around the fuel rail stop bracket.
Tight fight + engine vibration/movement = 1 or more wires being rubbed through and intermittent shorting of an injector. Check your coil wiring harnesses as well.
Give it the close eyeball. The slightest little cut is all it takes.
HTH
Tight fight + engine vibration/movement = 1 or more wires being rubbed through and intermittent shorting of an injector. Check your coil wiring harnesses as well.
Give it the close eyeball. The slightest little cut is all it takes.
HTH
Thread Starter
Le Mans Master
Joined: Nov 2009
Posts: 6,119
Likes: 156
From: Huntington tx
Will give it a look! I certainly have been doing a lot of work on the top end and could've done something. The start of many problems have been the result of fixing others.
Team Owner
Joined: May 2001
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From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
Tech Contributor
Joined: Dec 2006
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From: Van Buren Arkansas
Wounded Warrior Escort '11
If the misfire was related to the throttle position sensor, I would expect it would throw a TCS code(s). I'm sort of wondering if you have a grounding issue with the fuel pump itself as it has its own ground. Another quick thought would be a sticking throttle plate.
Thread Starter
Le Mans Master
Joined: Nov 2009
Posts: 6,119
Likes: 156
From: Huntington tx
I'll work on the car in the morning.
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Thread Starter
Le Mans Master
Joined: Nov 2009
Posts: 6,119
Likes: 156
From: Huntington tx
Found the problem, a sparkplug wire was jumping to the header pipe on the right of the dipstick tube. Really couldn't find a way to put more space between them, so I cleaned the sparkplug boot and brushed on some liquid tape. No miss now, but it's only a.temporary fix until I buy new sparkplug wires or find a better solution.
Last edited by sfc rick; Oct 3, 2011 at 07:33 PM.
Drifting
Joined: Aug 2006
Posts: 1,523
Likes: 34
From: King George Virginia
Glad to here you found the problem. The car will act the same way if one of the coil packs are going bad. They will misfire under load (acceleration) but be perfect under idle. Good Catch.
Safety Car
Joined: Jun 2005
Posts: 4,977
Likes: 256
From: St. Louis Missouri
Found the problem, a sparkplug wire was jumping to the header pipe on the right of the dipstick tube. Really couldn't find a way to put more space between them, so I cleaned the sparkplug boot and brushed on some liquid tape. No miss now, but it's only a.temporary fix until I buy new sparkplug wires or find a better solution.
Thread Starter
Le Mans Master
Joined: Nov 2009
Posts: 6,119
Likes: 156
From: Huntington tx
Safety Car
Joined: Jun 2005
Posts: 4,977
Likes: 256
From: St. Louis Missouri
They do. However, they are unnecessary and, in my personal opinion, ugly. 
MSD wires have an end that will allow you to bend/shape them away from hot parts. I apparently missed double checking my wires after doing some work one day. I imagine the OP had a similar situation.
MSD wires have an end that will allow you to bend/shape them away from hot parts. I apparently missed double checking my wires after doing some work one day. I imagine the OP had a similar situation.
Thread Starter
Le Mans Master
Joined: Nov 2009
Posts: 6,119
Likes: 156
From: Huntington tx
I found my oil dipstick tube was pushing the sparkplug boot onto the header pipe. I noticed the notch for the dipstick on the cover was further over so I pushed the dipstick tube over to the notch. It made plenty of room.
Last edited by sfc rick; Oct 3, 2011 at 07:34 PM.
Team Owner
Joined: May 2001
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From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
