Totally lost ---- have searched and searched and can't figure out my miss

[withoutfear33]

Bent or stuck valve will do this. Have you done a compression test?

i have not done a compression test, is there a gauge i can rent from a parts store? or where would be the place place to obtain one?

 

[withoutfear33]

Intake gaskets will do this they deteriorate replace if have problem like this.


Sent from my iPhone using Tapatalk

is there a way to determine if my gasket has gone bad before tearing into it?

 

[IOWNJUNK]

You can rent a compression tester at most auto parts stores.

You can check for leaks with a can of carburetor cleaner, spray it around the edges of manifold and on vacuum lines and listen for changes in idle speed.

 

[burkey05]

sounds like you only have a problem when the truck goes into closed loop(warm)

check out this thread. in particular post #22

http://67-72chevytrucks.com/vboard/showthread.php?t=520198

i'd check oxygen sensor and timing first

maybe try unplugging oxygen sensor to keep it in open loop and to see if its the problem, and to make sure your CEL light is working

 

[volunteerff21]

How about your ignition module?

Sent from Robl@and!

This^^^ Most auto parts stores will test them for free.

 

[withoutfear33]

This^^^ Most auto parts stores will test them for free.

Can it be replaced without pulling distributor?

 

[volunteerff21]

Can it be replaced without pulling distributor?

It's underneath the cap. It can be removed without pulling the whole dizzy. It's number 6 on this diagram.

You must be registered for see images attach

Sorry I can't walk you through step by step how to remove it, it's been a while since I've done one on a TBI. But once you pull the cap it should be fairly straight forward.

 

[IOWNJUNK]

Remove cap
Remove two harness connectors
Remove two screws
Remove ICM
Replace in reverse order

Get old one tested before you buy new one. They aren't cheap.

 

[skylark]

Remove cap
Remove two harness connectors
Remove two screws
Remove ICM
Replace in reverse order

Get old one tested before you buy new one. They aren't cheap.

Don't forget the grease on the heat sink of the module.

 

[withoutfear33]

Remove cap
Remove two harness connectors
Remove two screws
Remove ICM
Replace in reverse order

Get old one tested before you buy new one. They aren't cheap.

can i get this tested with it being removed? or does it have to be on the vehicle? i have never messed with one before. and does the truck need to be warmed up when being tested since thats when its giving me issues.