Q-Jet E4ME Help

[CaliDude76]

Hey fellas!,
Good to be back here...hope all is well with everybody!!

I need some help with my carb...it's the infamous Quadrajet E4ME computer controlled set up (that I have to have running right to pass smog). Good ol' California....

However...I pulled my truck out of the garage a while ago...smog is due...and I can not get this damn thing to run right.

Idles like ****...rich.., cold morning starts are a mess...coughs all over itself..I set the idle up to stop it from falling on its face..then the rest day it gets increasingly higher.

Try to turn up the fast idle for mornings...just a few ticks..and it won't come down...I turn it all back down and it' s bucking and dying at stoplights. Tried messing with timing and I'm just chasing it everyday.

Some days I can get it to do good....then it varies the next day.

Been wanting to drive it on a daily...but I'm fighting it.

Pulling my hair out over here. It used to run spectacular before I parked it and started restoring her.

I can not seem to find that spot
I also notice once I try to make adjustments...the RPM's vary on it's own...it almost seems like it's fighting itself..

Any ideas...tricks...or anything would help.
I'm on the verge of just pulling it off and getting a new one...
I sourced one for $350

 

[Craig 85]

Not sure where you're at in Norcal, but when I lived in the Bay Area, I had the Carburetor Refactory in Richmond rebuild the carb on my '79 (no electronics). I think it was about $300 7-8 years ago. Never had any issues with it while I owned the truck.

https://www.carbkits.com/

 

[bucket]

Check for vacuum leaks.

Is the choke closing when cold and then opening all the way when warm?

Could be some dirt or grit in a passageway somewhere. Run the engine with the air cleaner off and quickly cup your hands (very briefly) over the carb inlet a few times. The abrupt pressure changes "might" dislogde whatever may be stuck.

 

[legopnuematic]

If I understand correctly, your truck has sat for a while? If it has you might want to see if what fuel was in the carb when It was parked didn't turn into goo and plug up some passages. Sounds almost like the Idle mixture circuit is clogged or some other circuit. If it was running good in the past, all it might need are some new gaskets and a good cleaning of the insides. I'd recommend to get some of these brushes meant for cleaning air brushes- 5pc Airbrush Cleaning Brushes
These pictures are of a Bay City 2-Jet, but the holes for the Idle and off Idle transitions are basically the same. Run the brushes and plenty of cleaner through them and even snake some stranded copper wire through them to get any crud out of them.

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[1987 GMC Jimmy]

Hey fellas!,
Good to be back here...hope all is well with everybody!!

I need some help with my carb...it's the infamous Quadrajet E4ME computer controlled set up (that I have to have running right to pass smog). Good ol' California....

However...I pulled my truck out of the garage a while ago...smog is due...and I can not get this damn thing to run right.

Idles like ****...rich.., cold morning starts are a mess...coughs all over itself..I set the idle up to stop it from falling on its face..then the rest day it gets increasingly higher.

Try to turn up the fast idle for mornings...just a few ticks..and it won't come down...I turn it all back down and it' s bucking and dying at stoplights. Tried messing with timing and I'm just chasing it everyday.

Some days I can get it to do good....then it varies the next day.

Been wanting to drive it on a daily...but I'm fighting it.

Pulling my hair out over here. It used to run spectacular before I parked it and started restoring her.

I can not seem to find that spot
I also notice once I try to make adjustments...the RPM's vary on it's own...it almost seems like it's fighting itself..

Any ideas...tricks...or anything would help.
I'm on the verge of just pulling it off and getting a new one...
I sourced one for $350

If you need it rebuilt, send it to Mountain Man Carb in Hackett, AR. $200 plus shipping. They did mine, and I’m doing just fine. You just send it in the mail, bolt it in when it comes back, and you don’t have to worry with it. Before you give up, though, check for vacuum leaks as previously mentioned, and make sure the carb is bolted down properly. I’m not soliciting for them, by the way, but there aren’t many people who know the E4MEs inside and out, but they did a good job on mine for considerably cheaper than the figures that are floating around on this thread.

 

[CaliDude76]

If you need it rebuilt, send it to Mountain Man Carb in Hackett, AR. $200 plus shipping. They did mine, and I’m doing just fine. You just send it in the mail, bolt it in when it comes back, and you don’t have to worry with it. Before you give up, though, check for vacuum leaks as previously mentioned, and make sure the carb is bolted down properly. I’m not soliciting for them, by the way, but there aren’t many people who know the E4MEs inside and out, but they did a good job on mine for considerably cheaper than the figures that are floating around on this thread.

Funny you mention the vacuum situation...I just got off work about an hour ago, and the truck was sitting all day since this morning. It started up and idled good on its own.

But...it increasingly got higher, and wouldn't come down at all. So...I grabbed my handy long screw driver...loosened the air cleaner to turn the fast idle down and when I moved the cleaner up the idle dropped and acted weird.
I wiggled the air cleaner some more and it fluctuated.

Now..I'm wondering if I do have a bad hose or something is rubbing when I mess with the air cleaner.
I can see at least three vacuum ports with lines on my carb.

 

[CaliDude76]

Not sure where you're at in Norcal, but when I lived in the Bay Area, I had the Carburetor Refactory in Richmond rebuild the carb on my '79 (no electronics). I think it was about $300 7-8 years ago. Never had any issues with it while I owned the truck.

https://www.carbkits.com/

Actually...I live in a little town everybody commutes to from the Bay Area....Los Banos. I know Richmond. May have to check that lead out! Thanks

 

[CaliDude76]

Check for vacuum leaks.

Is the choke closing when cold and then opening all the way when warm?

Could be some dirt or grit in a passageway somewhere. Run the engine with the air cleaner off and quickly cup your hands (very briefly) over the carb inlet a few times. The abrupt pressure changes "might" dislogde whatever may be stuck.

I think I'm going to inspect all vacuum lines..it does seem like it might be. It runs like it wants to cure itself...like it'll idle real good for a couple of stop signs...then the third stop light...it's back to loading up and smelling rich.
I keep twisting on idle screws chasing it...but It's just to erratic right now
Need some time on it

As far as the choke plate goes...the other day when I was tweaking with it..it wasn't opened fully...I mean not straight up and down...but it was opened enough and at operating temp.
Not sure about cold choke fully closed.
Need to inspect that in the morning

I know there's an electric choke that I can adjust..not sure if I want to dive into that one.
Also..the CHOKE light is on...which I know shouldn't be. It stays steady lit too....that's a big clue

 

[Colin]

Run a qt of MMO (Marvel Mystery Oil) thru it in a full tank of gas.

 

[dougbert]

the best book to understand, fix and perform with the Q-Jet

https://www.amazon.com/dp/1932494189/

This guy has rebuilt 40+ engines mostly with Q-jet

He does rebuild them, but has a 6+ month back log. He will redo the bottom butterfly quickly and you rebuild the rest. The book describes all of that, what model number you have, the whole she-bang


here is a video on him on his Q-Jet doing a 1/4 in 11.66 secs

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dougbert

 

[k-5]

If your choke light is on you should check for power at the terminal on the choke thermostat. The electrical power runs thru a oil pressure switch If you have no power at the terminal there is a fuse for that to check first and then check the switch itself if the fuse is ok.

 

[Raymond84]

350 SB with quadrajet with electric choke. Latest dilemma. Choke light stuck on and truck won't idle down. I was chasing down why the oil pressure gauge stopped working. At this point the choke light never came on, truck idle stayed high when cold and when it reached operating temp you could hit the accelerator and it would drop down and idle correctly. Changed the pressure switch next to the oil filter and found the wire on the oil pressure sender next to the distributor had fallen off. I reconnected the sender wire and now the pressure gauge shows the oil pressure again. Now the choke light stays on and the engine won't drop down to idle as it should. I may put the old switch back in and see if the choke system works like before. Carb is new Chinese Quadrajet knockoff.

 

[Ricko1966]

350 SB with quadrajet with electric choke. Latest dilemma. Choke light stuck on and truck won't idle down. I was chasing down why the oil pressure gauge stopped working. At this point the choke light never came on, truck idle stayed high when cold and when it reached operating temp you could hit the accelerator and it would drop down and idle correctly. Changed the pressure switch next to the oil filter and found the wire on the oil pressure sender next to the distributor had fallen off. I reconnected the sender wire and now the pressure gauge shows the oil pressure again. Now the choke light stays on and the engine won't drop down to idle as it should. I may put the old switch back in and see if the choke system works like before. Carb is new Chinese Quadrajet knockoff.

Start a new thread so as not to confuse people with this one. Different poster,different car,different situation, so this will get confusing when people read the first and second post. Reply to that,you think they are replying to you,but they never read your post. And 1/2 the factory reman quadrajets are junk,a Chineese knock off I wouldn't even attempt. A qjet is not a one size fits all. If it wasn't specific for your year,your engine,your distributor,your transmission. You are going to have to do research,buy a book etc.and learn how to tune a quadrajet. Edited to say glad you were able to get a good knockoff qjet. I hope it continues to work well for you

 

[Raymond84]

Found the problem. The fuse for the choke blew during all my testing. Replaced the fuse and the choke light is off and the truck idles down after it warms up like its supposed to do. I still have the original Quadrajet as a backup. I appreciate all the comments and help. Next time I post I will open a new thread.

 

[DoubleDingo]

If you're going to inspect all of the vacuum hoses, may as well just replace them. I went through a similar issue and ended up replacing all of the vacuum hoses, and it helped a bunch. Still have some under load issues, but part throttle it runs like a top. Definitely run some cleaner through it, all it will do is help get any crud out.