85 problem
Thread Starter
Instructor
Joined: Jan 2006
Posts: 173
Likes: 0
From: Cleveland Ohio
85 problem
Need some help finding what is wrong with my 85. Last year I had it out and broke down. Looked under tha car and the cat was glowing cherry red. Had it towed home and found the dist cap had a large hole blown threw it under the coil. Bought a new cap and got it running. Now the car is running pretty bad. no pick-up. I know most of the problem should be a bad cat. Is there anything else I should be looking for?
Thanks
Gary
Thanks
Gary
Team Owner
Joined: Sep 2001
Posts: 62,067
Likes: 1,723
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Your cat is plugged up solid, no doubt.
Replace with a newer, higher flowing cat, like Random Tech or Car-Sound.
Replace with a newer, higher flowing cat, like Random Tech or Car-Sound.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
These guys are almost certainly correct, I just hate to see a part condemned without, first, testing it. If you can, screw in a low pressure, pressure gauge like one for a carbed engine. Otherwise start it up and rev the engine. Is it sluggish? Probably. If so disconnect one or both pipes from the exhaust manifold(s). Better yet, on your '85, unbolt the 4 bolts that attach the cat to the front "Y" pipe. Try revving the engine, again. Does it rev MUCH, MUCH, more freely, disconnected? If so, we all guessed correctly. Another "test" if it fails the above test is to remove the cat from the car, (you already have it half off) and take a pipe, crowbar or the like, and break out all the melted down catalyst left inside. Then you can bolt the cat back up and road test the car. If it runs better, the cat was plugged.
RACE ON!!!
RACE ON!!!
Drifting
Joined: May 2003
Posts: 1,647
Likes: 28
From: Woodbridge NJ
I had the same problem with my 84. In fact the car was so hot that when I turned it off the engine remained running. After about 5 minute and a little help from above the car shut off. I limped the car home and gutted the cat and its been that way for 3 years. You'll know as soon as your disconnect the cat from the front Y pipe as CFI-EFI mentioned.
Good luck.
Good luck.
Melting Slicks
Joined: May 2001
Posts: 3,270
Likes: 26
From: Winchester VA
Cruise-In V Veteran
A very quick way that I have used many times is to simply remove the O2 sensor and drive or rev as CFI suggested. The hole is big enough to make enough of a difference to be felt. On an 85 you only have one to choose from, for later model years with mutiple sensors, remove the pre-cat sensors.
Unplug the O2 sensor from the harness first, then remove the sensor with a 7/8 wrench or O2 sensor socket (available at local parts store, it will prevent stripping which is likely on an old sensor).
Unplug the O2 sensor from the harness first, then remove the sensor with a 7/8 wrench or O2 sensor socket (available at local parts store, it will prevent stripping which is likely on an old sensor).
Last edited by Steve85; Apr 3, 2006 at 10:49 PM.
