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1985 Caprice Classic - Problems starting
09-04-2012, 09:21 PM
I just got a 1985 Caprice Classic, V8 305. I sometimes have trouble starting it when the engine is cold. When I received the car from a family member, he gave me some spray for the carburetor. This does the trick, but I would like to fix it so that I do not have to resort to this.
The visor has some instructions for starting the engine. The directions say to depress the gas pedal once before trying to start, and 2x when it is very cold outside. I'm concerned that the car won't start at all when the winter comes..
Where should I start to troubleshoot this issue?
09-04-2012, 11:21 PM
Rebuild the carb. It sounds like there might be some gumming of the passageways, plus the accelerator pump piston may have become hard and won't seal properly.
09-05-2012, 06:56 PM
with a carb engine the vacuum created by the rotating engine sucks fuel out of the carb into the engine. this is quite different from engines inuse today.
poor cold start means your choke is defective leaking broken. tests and checking of these components need be done. this is when you only have a poor cold start.
IF THE ENGINE RUNS GOOD AFTER THE POOR COLD START THE REBUILDING OF THE CARB WILL NOT HELP.
the choke system needs checking for component replacement[choke stove,linkage on this , also the choke pull off/throttle plate adjustment].
have a repair shop that is familar with this check this out. the choke plate adjustment is .170in.GAP. high speed idle 1500rpm. hot idle 600rpm in drive.
09-05-2012, 08:37 PM
okay lets make this easy
when the engine is cold hit the pedal down twice and do not attempt to start
remove air cleaner lid and make sure the choke flap is closed if it is not the linkage may need to be cleaned. please ck this and report back
if the choke plate is not completly closed this is most likely your cold start problem.
09-05-2012, 09:53 PM
I forgot to say keep that carb cleaner away from any wiring and rubber parts or it will destroy it.
it is also good paint remover.
09-09-2012, 10:02 PM
So I pumped the pedal twice, opened the air cleaner and it looked like the choke plate was in the closed position. I poked around a little and manually moved the pull off and plate a little. I noticed that there was some play in the choke plate and I pulled on it gently to leave it in a position that was slightly more open.
I put the air cleaner back on and tried to start the car. It started right up... I wasn't able to start it this morning before messing with it or the past few days. I waited a couple hours and tried to start it again and it was fine.
I'm not exactly sure what I did... maybe the plate needed to be open a little more for it to start.. here a picture of the carburetor. Do you know what kind it is?
09-10-2012, 08:05 AM
this is a quadrajet 4 barrel carb. the choke pulloff is a vacuum controlled device. when the engine is cranked vacuum opens this throttle plate .172 inch gap to then get the engine running when cold.
since this plate closes when the throttle is depressed that is proper, so that would mean the choke pull off has a vacuum leak/hole in the diaphram. replace this part and adjust so that you get the proper opening when the engine is running/vac on the pull off.
09-10-2012, 10:03 PM
Technically, it's the E4ME with electronic mixture control, idle air bleed, lean and rich stops, and TPS. Once you resolve the choke set and pulloff adjustments, and WOT choke override, it might be good to check the MC solenoid adjustment and TPS settings. The MC setting being as neutral as possible will likely give you the best cold weather starting without risk of flooding.
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