Wiggles

Greetings,

Long story short, my E4ME needed to be rebuilt.

Disassembled the carb then soaked the airhorn, float bowl and throttle body in Tyme-1 cold parts cleaner, dried it with compressed air, and reassembled with a new parts kit. A friend loaned me the necessary tools to adjust the MCS/lean stop (double D t-bar tool and the metal tube to place over the throttle side primary metering jet) and the idle air bleed cane-shaped gauge. All adjustments were made according to the service manual, the Haynes guide, and the information found on this site.

Installed the carb and started up the car, it idled great...until it came time to blip on the throttle to activate the unloader tang and calm down the engine...nothing happened; the rpms stayed the same. Pulled the air cleaner off and inspected the linkage, nothing was binding. Played with this for nearly 30 minutes until I tried something...manually tapping down the fast idle cam, causing it to lock into place and it worked. The engine dropped down to about 850 rpms like it once did. As soon as I tapped on the gas pedal or pulled on the throttle cable, the fast idle cam would "snap" up (the same way it behaves when you first tap on the gas pedal to start up a cold engine) and the idle would increase to about 1900 rpms.

Pulled the carb off and placed it on my work bench; removed the choke and associated linkage to investigate. Based on the diagrams, everything was in place. I then went over to my 78 T/A and used that qjet M4MC model as reference; everything appeared fine. Went back outside and reinstalled the carb, same problem.

Here's what I did next: removed the choke element completely and unplugged the pigtail. Since there was no resistance due to the choke coil being removed, the fast idle cam stayed down and thus the car was driveable. Ok, so what next? Is my choke coil bad or is the linkage so worn that it's causing the fast idle came to slip? Or am I a major fool and installed the choke linkage incorrectly? I really hope my story makes sense and that someone here can help determine what the issue is. I'm really puzzled at this point.

-Wiggles

Damon

Sounds a bit like you got the choke element dialed up too tight (never fully releasing) or it's just not getting voltage to it to heat it up.

If pushing the fast idle cam lever down manually returns you to normal idle speed, there is really only one thing left- the choke element isn't relaxing when it gets hot (do you have full voltage to it??) and it's hanging the thing up at high idle.

Wiggles

Damon, thanks for the reply. At first, I also thought the choke was too far counter-clockwise. After incrementally adjusting it, I discovered that no position was correct! Only when the choke coil did not touch the inner lever in the housing did the fast idle cam stay down.

This evening, I turned the engine over and used a volt meter on the choke connector; it measured 13.82 volts, give or take. Sounds like my choke element has finally taken a dump. I've ordered a new one and will report as soon as it's installed.

Wiggles

New choke arrived yesterday and installed it; idle now kicks down to the proper curb idle speed. I've learned a valuable lesson during all of this: the choke is far more important that I've ever imagined and never dismiss the idea that it CAN go bad!

Thanks!


And for anyone else saying, "oh, the ccc qjet is hard to rebuild and adjust"---no, no it's not. Take your time, read, read some more, apply, and it's highly doable.

sofakingdom

iTrader: (1)

Often, what happens is, people put a gasket behind the choke stat where it sits in that bowl thing, as that seems like it would be the thing to do; which prevents the stat's ground contact (the outer edge) from touching ground. When that happens, it acts like the choke stat is bad.

Those RARELY fail in any way except mechanically breaking into pieces.

Damon

Sofa's right- electric chokes get installed with NO gasket. The inner edge of the choke has to touch the choke housing to ground itself.

Another test you can do with the choke element (without running voltage to it) is measure it's resistance (at room temp). A brand spanking new one will be around 10 ohms, sometimes even a little less. A well-used but still serviceable one will be around 15, maybe 20. Anything over 25 and it's shot. It might still "work" to some degree or another, but it won't be working properly.

Wiggles

I was aware of negating the gasket during installation, there wasn't one in the housing prior to disassembly and rebuild, there wasn't one installed during reassembly and Cliff Ruggles' book has also said not to use the gasket with an electric choke either. It makes sense as the + voltage going in would need to be grounded to complete the circuit.

I just measured the old choke coil --11.2 ohms steady. I can't tell you how many times I've adjusted the old choke cw/ccw in an attempt to allow the fast idle cam to drop during warm up but to no avail. Unless there's sorcery at work or I'm going mad, this old choke's bimetal coil is worn.

Damon

Hmmmm. That's odd.

Why don't you bench test it with 12V and see how long it takes to move ~90*.

Does the tab on the end of bimetal coil have an eyelet shape (an open hole)? If you install that type you MUST get the eyelet ON (surrounding) the pin on the arm inside the choke housing. If you install it off to one side it will close the choke but it won't be able to force it open again (it becomes a pusher-only, instead of the intended push-pull functionality). With some choke linkages they have enough internal friction they won't reliably drop down on their own without the choke element helping them out.

Or maybe the electrical tab on the choke element is rusted and not making good contact with the feed wire.

Other than the coil testing good but being bad (which can happen) those are about the only other things I can think of that might be causing a problem.

If you find the old choke element is still good, well, you've got a spare now!

Wiggles

1 . Why don't you bench test it with 12V and see how long it takes to move ~90*.

This I have not tried yet (need a power source). I actually could use some form of a power source, any recommendations such as Sears or (Harbor Freight?)

2. Does the tab on the end of bimetal coil have an eyelet shape (an open hole)? If you install that type you MUST get the eyelet ON (surrounding) the pin on the arm inside the choke housing. If you install it off to one side it will close the choke but it won't be able to force it open again (it becomes a pusher-only, instead of the intended push-pull functionality). With some choke linkages they have enough internal friction they won't reliably drop down on their own without the choke element helping them out.

Yes, the choke coil has the eyelet and was installed over the pin (and not on the left or right of the pin). I made the mistake of installing it (earlier on) on the outside; it was dumb to not use a flashlight at nighttime


3. Or maybe the electrical tab on the choke element is rusted and not making good contact with the feed wire.

The L-shaped connector is completely clean and free of contaminants

4. Other than the coil testing good but being bad (which can happen) those are about the only other things I can think of that might be causing a problem.

Ha, absolutely, this is a strange case indeed

5. If you find the old choke element is still good, well, you've got a spare now!

I won't put a 7.92x57mm bullet through it....yet.

Thanks for all your help with this, it's definitely led to alot of troubleshooting, testing and reading, whew.

Damon

Just run some jumpers from your battery posts to the old choke element to test it. Doesn't draw much juice- just an amp or two. Nothing that would overload typical jumper leads, let alone a small set of jumper cables.

gearhead141

I have the same issue with my E4ME. I have read your post and others as well. I thought perhaps mine was exactly the same issue, so I disconnected and removed the choke t-stat. Started the car and the idle is at 1500-1600 and no amount of blipping the throttle brings it down. I'm really starting to think there is a problem with the fast idle cam. Can these go bad? I rebuilt the carb last October and it was running fine until March when the idle started getting progressively higher over a number of days. Now, if I run for just a few minutes and then shut it down, it diesels. Where do I go from here?

Wiggles

Damon, if the weather permits this weekend, I'll check the old choke unit using jumper cables and my battery. I'm curious about the result as well.


I began to think the same thing, "does the fast idle cam unit become so worn out that it causes slippage?" These past two weekends, it's been running fine and calming down once the choke is fully warmed up, like it once did. The diesel problem you spoke of was also something I've encountered at random times. Have you tried making any minor adjustments to the lean stop / idle air bleed plunger?

gearhead141

Have you tried making any minor adjustments to the lean stop / idle air bleed plunger?[/quote]

No, I've avoided adjusting the Idle Air Bleed due to the fact that it was running fine before hand. What could have happened to change that? Perhaps an o-ring breaking?

Wiggles

No, I've avoided adjusting the Idle Air Bleed due to the fact that it was running fine before hand. What could have happened to change that? Perhaps an o-ring breaking?[/QUOTE]

Can't really say if that's the cause or not. One thing I can say, based off experience and observation, I've found the ccc qjet to be touchier than its previous incarnation. And anyone, please call me out and correct me on this, but rebuilding and adjusting the M4MC qjet is fairly easier than the ccc type. Primarily, there's the adjustable part throttle and mixture idle screws to play with, this type has a lean adjust, rich stop, idle air bleed and idle mixture screws; changing one thing (especially the lean adjustment) causes everything else to be skewed. I've found this carburetor to be especially challenging to adjust. Thankfully, we have a very good sticky to read in the above carburetor section.

You could try making minor adjustments (and carefully noting how far clockwise / counterclockwise you've gone in case you need to revert back) and see where that takes you.

Damon

If you remove the choke element and open the throttle a little, it should INSTANTLY drop down to curb idle (throttle arm touching the curb idle speed screw on the driver's side of the carb) and the choke plate should go fully-open (vertical). If it's not, the linkage is gummed up/hanging up somewhere. Could just be dirt and crud. A good dousing of the entire choke linkage on the passenger side with carb cleaner is a good start.

There's a big triangluar shaped head on the end of a particularly beefy arm in amongst the choke linkages. That is supposed to provide the "weight" to drop the linkage open if there is no choke element present. You can also (gently) push down on it with your finger to manually open the choke linkages. Don't force it. Very little effort should be required. If it won't go, something's mechanically jammed and it's time to start taking the choke linkage apart to figure out what.

gearhead141

I removed the carb and noticed that the throttle blade is not completely closed. Adjusting the Fast Idle screw slightly opens the throttle blade. So I adjusted it to where the throttle is closed and the cam still makes contact. I appreciate everyones help. I'm just confused as to the root cause of this problem. It started when I was going to fuel up. I pulled up to the pump and the idle would not go down. It was so bad that I just left and parked the car. It of course dieseled when shut down. That was in March and I'm still trying to figure it out. I verified there were no vacuum leaks. I even went so far as to isolate the carb by capping off all vacuum ports. So my trouble shooting tells me it must be the fast idle circuit of the choke. I ohmed out the choke t-stat and it is within limits. My t-stat is non adjustable, i.e. it fits into a slot on the housing. I have the FSM but it really doesn't tell me much; I've learned more off this board.

Wiggles

Ok, ran jumper cables to the choke coil as suggested and it heated up (slowly). It was worse than watching water boil. During the timeframe of 5 minutes, (that's quite long for 100 degree F summer heat) the eyelet section rotated a little over 45 degrees. I left it connected while I checked oil in two vehicles and came back and it was in the same place.

potterc32

iTrader: (1)

I know I'm posting on an old thread, but I seem to be having the same issues. Happened with consecutive carburetors I rebuilt (losing faith in myself!!). CCC Qjet, idled low before rebuild, now mixture seems to be good, just idles at around 2000 rpm. I can pull the throttle linkage down to bring the idle speed down, but it just "springs back and does not contact the idle screw or the fast idle solenoid. Pulling the fast idle CAM down (towards front of car) allows the throttle to come back down to normal, but of course tapping gas pedal reverts it back.

I wouldn't say it took "force" to pull the cam downward, but it did not just fall with ease. Anyone know of a video or some really good pictures of how the choke linkages are installed?

P.S. I will go and remove gasket from my electric choke tonight!!