Csi easy fix? 83 sc

[Jp10468]

Hello

Got a 83' sc engine starts up, revs up ok till warm

When approaches warm remains elevated around 2k for a longer time and goes back to 920 or so rpm

When fully warm, idle stays at 2k after throttle given

When i remove the oil filler cap and replace it idle goes back to 920 until throttle is given.

If i never give it throttle, rmp will stay at 920 no matter how warm it is

Car will shut off if i remove oil cap for over 2 sec.

Fuel pressures are around low normal

I understand there is a hundred possibilties and troubleshooting. I have been at this for a long time and are one step away from bringing it in to a ?mechanic?

Thanks
John

[Scott R]

I would disconnect the throttle link rod to the throttle body and try the test again. If that's ok then I would suspect the distributor is hanging up.

[Josh D]

First thing I would check is to see if the metering plate is sticking. Remove air filter cover and air filter and push up on the metering plate arm to make sure it is moving freely. And like Scott said, make sure the distributer plunger is moving freely with the metering plate.

[Jp10468]

Thanks. Will do

[LM3929]

Try taking the vacuum line off of the decel valve and plugging the vacuum line and then trying the idle, that is what I had to do with my 83 when it actually ran.

Lorne M.

[Scott R]

Originally Posted by Josh D

First thing I would check is to see if the metering plate is sticking. Remove air filter cover and air filter and push up on the metering plate arm to make sure it is moving freely. And like Scott said, make sure the distributer plunger is moving freely with the metering plate.

Sorry I need to clarify, I was referring to the mechanical advance in the distributor. When they get dirty they hang after accel.

[Josh D]

Originally Posted by Scott R

Sorry I need to clarify, I was referring to the mechanical advance in the distributor. When they get dirty they hang after accel.

Yes! That can happen too!!

[pete3799]

Post your fuel pressure numbers (system,cold, warm, and residual) and your WUR part number.
Do a vacuum leak test.
Without this info everyone is just going to be guessing.

[Joe Bob]

Fuel pressures and intake leaks are the main issues with CIS.

[mca]

Did you try this?

It gets my vote. High probability of being the culprit and a very easy test to perform.

Try taking the vacuum line off of the decel valve and plugging the vacuum line and then trying the idle, that is what I had to do with my 83 when it actually ran.



Lorne M.

[Jp10468]

Thanks Josh and Scott.

It seems like the lever in the air box is a bit stuck causing my issues. Improved by pulling slighty down on the lever in the air box. Will need to clean. Seems like this should fix my high idle.
Thanks again Pelicans.
As far as the Dizzy, Vaccum, air leaks yeah i got them too. But thats another story. I am still slap happy that idle has improved somewhat.

[Scott R]

Originally Posted by Jp10468

Thanks Josh and Scott.

It seems like the lever in the air box is a bit stuck causing my issues. Improved by pulling slighty down on the lever in the air box. Will need to clean. Seems like this should fix my high idle.
Thanks again Pelicans.
As far as the Dizzy, Vaccum, air leaks yeah i got them too. But thats another story. I am still slap happy that idle has improved somewhat.

Pulling down on the arm actually adjusts the mixture a bit. Look up a thread by "souk" that explains why that happens.