Need Some Help
09-01-2005, 12:54 AM
#1
Registered User
Thread Starter
Join Date: May 2003
Location: Valpo,IN
Posts: 95
Need Some Help
WHat I have is a 96 Maro 383 cc 306 ported heads headers Bla, bla, bla.
The PCM is a OBD1 and has been reprogramed with Tunercat.
Car has run good in the past and recently started dropping cylinders at random. Every time it is started (cold or hot doesnt matter) it drops a different cylinder and usually 1 dead completly and 2 others mis firing intermitent. If you rev it up a lil, it doesnt seem to help.
If you shut it off and restart it will have differnt dead cyl's and the 1's that were dead will B fine.
So far I have tried
Compression and leak down test
Swapping injectors from good cyl's to bad 1's = no diff
fresh plugs / verfied spark condition
Verified fuel supply and pressure
checked for vacumm leaks
adding and subtracting fuel in the individual cyl trim (idle and off idle) tables
recalibrated MAF tables (added fuel) = seams to help
and I'm sure a few others my toasted brain has forgotten
I am at a loss here and need a direction to go so if any 1 has 1 i will gladly listen and try
The PCM is a OBD1 and has been reprogramed with Tunercat.
Car has run good in the past and recently started dropping cylinders at random. Every time it is started (cold or hot doesnt matter) it drops a different cylinder and usually 1 dead completly and 2 others mis firing intermitent. If you rev it up a lil, it doesnt seem to help.
If you shut it off and restart it will have differnt dead cyl's and the 1's that were dead will B fine.
So far I have tried
Compression and leak down test
Swapping injectors from good cyl's to bad 1's = no diff
fresh plugs / verfied spark condition
Verified fuel supply and pressure
checked for vacumm leaks
adding and subtracting fuel in the individual cyl trim (idle and off idle) tables
recalibrated MAF tables (added fuel) = seams to help
and I'm sure a few others my toasted brain has forgotten
I am at a loss here and need a direction to go so if any 1 has 1 i will gladly listen and try
09-06-2005, 11:08 PM
#3
Registered User
Thread Starter
Join Date: May 2003
Location: Valpo,IN
Posts: 95
Re: Need Some Help
Well it has an OBD1 PCM so there is no crank sensor..
WE did try a good opti with the same result, also tried a new PCM with a diff program. and that mearly changed the dead cylinders
Next is new injectors and or a wiring harness.
Good thing for the donor car
WE did try a good opti with the same result, also tried a new PCM with a diff program. and that mearly changed the dead cylinders
Next is new injectors and or a wiring harness.
Good thing for the donor car
