Help: '78 Cj7 258 EGR problems

Jul 17, 2004 7 Replies
P

Subject Vehicle 1978 CJ-7, 258 inline six, Carter yf carb


PROBLEM with EGR setup



----------------------- CJ runs fine when it's engine is cold since the CTO stops vacuum to the EGR valve. It idles fine hot or cold.



When engine is hot and I step on the gas the motor hesitates and the engine delivers about zero power or stalls. I can't even drive it unless I rev the engine way up and only partially engage the clutch(but not fully engage clutch) and then it goes really slow and ultra gutless.


TEST



-------- I tested the EGR valve and it operates when vacuum applied as it should.


MY SETUP



--------- I have the EGR ported vac from the upper rear vac port of the carb running to the EGR CTO switch then to the EGR valve. That is all standard. But I do have one thing that is non standard or strange, the EGR valve has two ports/nipples on it please see my little diagram below (the EGR is round but I couldn't make the diagram that way here) ___ /EGR\ port 1 >>> ===(VALVE)===


Vote
Twitter Facebook LinkedIn
M

Has it ever run 'right' with that EGR valve?

It 'sure' sounds to me like you have the wrong one in there. It sounds like it is either opening too fast (worn out or broken spring) or it is too big internally letting too much exhaust back in.

One other thing to check for maybe is a vacuum leak at the carb base or at the intake manifold gasket. You can spray some carb cleaner along the gaskets when running and if the engine stumbles you have found a leak.

The EGR can give it fits if it already is leaky somewhere.

Other than that, if you don't need the thing for emissions, I would just leave it shut off.

By the by, do you have a charcoal canister in there with a vacuum operated purge valve? If so, maybe that is where the second nipple is supposed to go. The canisters also turn on with ported vacuum via the CTO valve.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

paul wrote:

Vote
Twitter Facebook LinkedIn
P

Thanks for the help guys. And thanks for digging up those part numbers. Good web site!

So I took the EGR off the intake manifold and I found a part number on the underside- I should have done that earlier - duh. Now that I found a part number I am hoping there is some way I can cross reference it to a Standard motor products part number or a Tomco part number so I can tell if it is a good part number i.e. the right part for the motor.

How do I figure this out?

See pictures of the EGR valve and part numbers I took out of the jeep at:

formatting link
or
formatting link
THE PART NUMBER or numbers are "E83-3001-00" and or "9510 11" and it looks like there is a manufactures stamp that says "TI"

You will likely be interested in this link

formatting link
it is titled "EMISSION CONTROL VISUAL INSPECTION PROCEDURES"

It looks to me like this is a very detailed training manual for California smog inspectors. It is for a honda but they are just using the honda as a sample for training. If the link dosent work just search google for "EMISSION CONTROL VISUAL INSPECTION PROCEDURES"

Vote
Twitter Facebook LinkedIn
L

formatting link

Vote
Twitter Facebook LinkedIn
M

If you are saying that yours doesn't match up with the numbers in Bill's link, then it is the wrong one.

It 'sure' sounds/looks like the wrong one. What is with the allen key anyway?

I would recommend you go to your local Jeep dealer and just order the right part.

I will guess the last owner couldn't find the right part so just stuck any old EGR on there not knowing any better or in a desperate need to pass the visual for emissions. (EGR legs rot off and they break loose)

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

paul wrote:

formatting link

Vote
Twitter Facebook LinkedIn

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required