1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Tach to zero, engine dead, until...

Thread Tools
 
Search this Thread
 
Old Dec 22, 2002 | 09:00 PM
  #1  
jerij's Avatar
Thread Starter
Senior Member
Tenured Member 15 Years
iTrader: (5)
 
Joined: Apr 2001
Posts: 336
Likes: 1
From: Cane Ridge
Tach to zero, engine dead, until...

The car is an SE. It is tuned to spec, and otherwise runs excellent.

About 20% of the time when I'm clutching and changing gears, the tach will go all the way to zero, engine dies, until I let back out on the clutch. This clutch change is the ones you make when you're turning in to another street or going over a pothole, etc. The regular gear shifting pattern is undisturbed.

I've checked the service manual for deceleration problems and the the items it listed I recently checked for.

Someone on another thread (FD) had mentioned their flywheel was too light and it caused their problem. I've not changed mine.

Any ideas?

jeryj
Reply
Old Dec 22, 2002 | 09:13 PM
  #2  
peejay's Avatar
Old [Sch|F]ool
Tenured Member: 20 Years
Liked
Loved
Community Favorite
 
Joined: May 2001
Posts: 12,856
Likes: 568
From: Cleveland, Ohio, USA
Does it otherwise idle okay when just sitting in neutral?

Also, are you saying that the tach first drops to zero, then a few sec. later the engine dies, or that they both happen at the same time? What I'm getting at is trying to figure if it's a stalling problem or an electrical bugaboo.
Reply
Old Dec 22, 2002 | 09:25 PM
  #3  
jerij's Avatar
Thread Starter
Senior Member
Tenured Member 15 Years
iTrader: (5)
 
Joined: Apr 2001
Posts: 336
Likes: 1
From: Cane Ridge
Thanks for the reply.

Under the "normal" scenario, the tach does a "slow" drop (thanks to the dashpot etal), then I let out on the clutch, and the revs begin to pick back up with throttle.

When it has its "colon attack", the darn tach/engine doesn't slowly go down. It will drop like the fuel has been cut off (this occurs with my foot OFF the gas and the clutch pushed in). Obviously when I let off the clutch, the car momentum starts it back up.

It only does this during a "prolonged" shift pattern (holding the clutch in while going over a speedbump, etc). It may be occuring on "regular" gear shifting, but since I make the shift so quickly, the car doesn't have time to manifest the problem.

Either way, this only occurs about 20% of the time during the "prolonged" shifts.

jeryj
Reply
Old Dec 22, 2002 | 09:34 PM
  #4  
peejay's Avatar
Old [Sch|F]ool
Tenured Member: 20 Years
Liked
Loved
Community Favorite
 
Joined: May 2001
Posts: 12,856
Likes: 568
From: Cleveland, Ohio, USA
I'd start by making sure the TPS is set properly, and the BAC valve isn't gunked up.
Reply
Old Dec 22, 2002 | 09:36 PM
  #5  
Project84's Avatar
Open up! Search Warrant!
Tenured Member 05 Years
 
Joined: May 2002
Posts: 3,838
Likes: 3
From: Kicking down doors in a neighborhood near you
Its not really momentum starting the car, its the rear wheels turning the tranny, and the tranny turning the engine when you let the clutch out, simulating a starter by rotating the flywheel.

Anywho, check the dashpot and TPS for proper adjustment. I had a TPS that would intermittently fail, and cause the vehicle not to start. Its a hard proplem to diagnose cause its intermittent.
Reply
Old Dec 22, 2002 | 11:33 PM
  #6  
Directfreak's Avatar
I am a Jeeper Now.
Tenured Member 20 Years
iTrader: (2)
 
Joined: Dec 2001
Posts: 9,371
Likes: 4
From: 3OH5
I've had this happen to me in the past. It was a poor connection on one of the fusible links. Check there.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
streetlegal?
New Member RX-7 Technical
13
Mar 17, 2022 02:46 PM
Thor 18
Interior / Exterior / Audio
4
Sep 13, 2015 08:39 PM
freq
Microtech
1
Aug 23, 2015 11:02 AM
freq
2nd Generation Specific (1986-1992)
0
Aug 21, 2015 03:30 PM




All times are GMT -5. The time now is 08:48 PM.