Shuddering in Overdrive - not coils, but fuel injectors? - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


1992-1999 Series I L27 (1992-1994 SE,SLE, SSE) & Series II L36 (1995-1999 SE, SSE, SLE) and common problems for the Series I and II L67 (all supercharged models 92-99) Including Olds 88's, Olds LSS's and Buick Lesabres Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.

Reply
 
 
 
Thread Tools Search this Thread
Old 07-07-2004, 11:02 AM   #1
Senior Member
Posts like a 4 Banger
Thread Starter
 
Join Date: Dec 2002
Location: New Jersey, USA
Posts: 147
Thanks: 0
Thanked 0 Times in 0 Posts
StoopidSavant is on a distinguished road
Default Shuddering in Overdrive - not coils, but fuel injectors?

Hello,

I've recently been reading about several threads that mentioned shuddering from the engine when the torque convertor locks up, and is easily mistaken as a transmission problem. Luckily for me, I read this the night before it happened to me, and figured that the same thing was happening to me - ignition coil(*) going bad.

Well, I'm 100 miles from home, and nothing to do except pop the hood the reseat all the plug wires - of course this doesn't help. I go another few miles with the OD shudder, then pull over and reseat all of the electrical connectors on the fuel injectors. Now it'* shudder free!

The same situation happened about a year and a half ago when I purchased the car, though it would shudder at any speed, in any gear, and it turned out merely to be loose fuel injector connectors. But yesterday, it showed the exact symptoms of coil failure: runs fine in lower gears, then starts acting up only when the TCC locks up. But after reseating the FI connectors, it was absolutely fine for 100 miles. A weak coil I can understand missing under load, but an intermittant FI should miss any time at all, right?

Can anybody give a plausible mechanical explanation for this?
StoopidSavant is offline   Reply With Quote
Old 07-07-2004, 12:01 PM   #2
Senior Member
True Car Nut
 
Join Date: Sep 2002
Location: Chicago, IL
Posts: 2,409
Thanks: 0
Thanked 1 Time in 1 Post
acg_ssei is on a distinguished road
Default Re: Shuddering in Overdrive - not coils, but fuel injectors?

Quote:
Originally Posted by StoopidSavant
Can anybody give a plausible mechanical explanation for this?
I can think of two, neither really solid, though:

1) When OD first engages, increased engine load requires a slightly richer charge in the cylinders, and the intermittently-firing injectors can't keep up with the demand

2) When OD first engages, the engine shifts in its mounts slightly due to powertrain stresses, and disturbs the loose wiring harness to the injectors
acg_ssei is offline   Reply With Quote
Old 07-07-2004, 06:37 PM   #3
Senior Member
Posts like a Turbo
 
Join Date: Mar 2003
Location: Indianapolis, Indiana
Posts: 311
Thanks: 0
Thanked 0 Times in 0 Posts
along is on a distinguished road
Default

i am gonna check these. I cant believe it could be this simple.....
along is offline   Reply With Quote
Old 07-07-2004, 07:00 PM   #4
Junior Member
Posts like a Ricer Type-R
 
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road
Default

Obviously this IS possible, as it seems to be the case this time, but 95% of the time, this will be ignition related, NOT fuel related.
willwren is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
For Sale: Acura Coils/injectors/fuel rail BillBoost37 Lounge 0 06-04-2007 05:51 PM
Went to store-had overdrive, coming back-NO OVERDRIVE Hafrod Buick 13 06-01-2006 10:44 PM
not good. NOT GOOD. (hit and run, not bad-BAD, but not good) repinS General GM Chat 13 11-26-2004 11:35 AM
Coils replaced and O2 too, but still having probs birchymm 1992-1999 24 11-19-2004 12:18 PM
overdrive or not to overdrive duffer26 1992-1999 10 03-13-2004 12:09 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 09:35 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.