Question: I have a question for the experts or folks who have dealt with the E4ME carb

[GerryLP]

I have been troubleshooting the original carb on Gail lately. She starts late (after second or third crank), the choke does not engage to get her to 2,200 rpm, and when she idles, she stumbles and dies off after idling for a while (almost as if she is not getting enough fuel in the reservoirs of the carb).

With the dwell connected, she is metering for a little while, and then the dwell needle goes dead and below 10 degrees. Shortly after this, she dies off. If I accelerate the engine, she goes back to metering with the computer and mixture solenoid to a neighborhood of 25 degrees.

She flashes only code 21 from the CCC. I am not sure how long this code has been there, but the procedure is pretty straight forward to correct the throttle positioning sensor, so I don't feel that it is a problem.

But when I follow chart 1, page 6E1-17 of shop manual for dwell is fixed below 10 degrees, and if I cover the throttle body with my hand, she goes back to metering. So obviously, I began looking for an air leak. I tightened the carburetor lid screws a bit, checked some of the connections, and I find nothing. So I went ahead and removed the carburetor, and while I looked around, I found that the primary wells' protruding portion on the side of the throttle body that are normally covered with plastic/rubber (I don't even know what they are called) and their associated shields are lose and cracked. See pictures

The phillips screw driver tip is pointing to it...

a close up of it without the plastic/rubber shield

The shield for the passenger's side on the carburetor is cracked and comes off easily as well.

So my question is, does it matter if they are missing the plastic/rubber shield?

 

[Peer81]

Hello Gerry,

The plastic / rubber is epoxy to do an easy fix when the primaries (and/or secondaries) are leaking. When looking into Doug's book he says this is a permanend fix but Cliff says this is only a temperary fix.

What is the problem you have. As the carb sits fuel is leaking through the bottom into the engine, and when running giving extra fuel. When you want to start the engine the fuel bowl is empty (there is only a little fuel in the acc. pump) so you first need to pump fuel into the carb (when cranking) to get her started. A way to check this (with the carb still on the engine) is after a few days check if there is still fuel in the bowl (is the float still floating or on the bowl floor).

What you can do is get a kit from Cliff or maybe others, I don't know of a better way to fix this problem. You need to remove the original bottom plugs, then tread the walls an put a imbus in them (with epoxy). If done right this would permanently fix the problem. One thing the imbus are to long so you need to shave them to work (primary not really but the secondaries do). The only problem (I think) when after inserting the imbus there is still fuel leaking there is no way to get it out again.

Greetings Peter

 

[LannyL81]

Gerry,
I have a spare complete E4ME that I put a kit into and then put on the shelf.
I removed all the epoxy off the primaries...just did not like it. I have not run the carb...always meant to.

Anyways I can send it to you to try if you want to. Let me know.

Lanny

 

[GerryLP]

Peter,

Yesterday, I went ahead and installed the carb back on to see if the "not-metering-dwell-needle-falls-under-ten-degrees" problem still is happening, and it still does it. The CCC metering comes back on if I cover the carb venturi with my hand... it is like it is getting too much air and the computer gives up.... But at least now I know that it is not causing the CCC to drop metering in the carb. It could be a leaky doughnut upstream from the oxygen sensor, IAW the shop manual.

Now, on to the hard starting problem, Could you use my pics and re-explain, so that I know what you mean for sure?

Lanny! Thanks buddy. But I have a spare carb as well.

GerryLP:cool

 

[GerryLP]

Ok guys, messed around some more with the Vette today. I got under the car, and I checked the driver's downtube on the front "Y" pipe, and I found the nuts loose enough to perhaps allow air to get in.

I then started her up and waited for the engine to get to warm temperature. As I was making the adjustments slowly and on "Park", the dwell readings were getting better and better. Once I was past 25 degrees, I went ahead and placed the gear selector on "drive", and I continued to make adjustments until the CCC was hovering around 30 (on the 6 cylinder scale).

I then took her out for a drive, and she drove fine and smoothly except for in 3 occasions were the engine just died on me. Once, the engine died on a turn while pressing the brake pedal, another time after starting her up again after leaving the grocery store, and then again after leaving the local Target store. It feels almost as a stumble or something, but when I tried to duplicate the problem, the engine would not quit. So, I am trying to figure out what the heck is up ...:eyeroleconfused:ugh:ugh

Any ideas?

 

[Peer81]

Hello Gerry,

To continue with your hard to start problem. First check when you didn't use the vette for about 4 days if the accelerator pump holes (above the primaries) are still pumping fuel into the carb. After the first time you pump the acc. pump all the way down it should refill with fuel from the fuel bowl. So after pumping 2 or 3 times you still should have fuel inside the acc. pump. If this is the case no problem. If after two times no fuel is coming out the acc. pump holes the isn't enough fuel in the fuel bowl.

What is the problem. What you see on the under side of the carb is a channel that channels fuel down under the primary jets and after that up again toward the venturi. The channel is closed by a brass (and later other) plugs (in your picture left side) so fuel stays inside the channels. Problem is or could be the plugs aren't that good over the years so they start to leak fuel. An easy fix is to put epoxy over the plugs (the plastic thing, right in the picture).

As said is't better to remove the plugs and put threaded plugs in them. The way to do this (if you're sure the plugs are leaking), is to remove the plugs.
What I did with mine:

But as I said, best to first check and then see if it's really necessary.
Hope it helps

Greetings Peter

 

[GerryLP]

Thanks Peter!

I will try the Marine Tex first for a temporary fix, and then later on when I get inside the carb for cleaning, I'll do the more extensive one. Thanks again!

GerryLP:cool

p.s. I ordered some from Jamestown Distributors, Bristol, RI

 

[GerryLP]

Well folks , I drove Gail to work today, and she drove divinely today. The engine temperature average 200 degrees (just slightly left of the "210" degrees mark). The acceleration was smooth and consistent. The transmission was responding nicely as well. And on the way home today, there was a 75 degrees afternoon, and she kept her engine temperature solidly at 200 - 210

Even the choke worked fine. The choke lock-out and heating element adjustment was what she needed. Her curb idle is a little low (correct for the stock cam, but not quite for the Extreme 268 cam), but other than that, she ran great!

So if you feel that carb stops from metering the fuel, cover the carb Venturi with your hand, and if it starts to meter again, then check for leaks on and around the carb, and specially check for air leaks upstream of the oxygen sensor.

 

[bill81vette]

Glad to hear it's running better!!!!!!!!

 

[Peer81]

Great to hear Gerry! Enjoy your '81!

Greetings Peter

 

[GerryLP]

I am stoked!!!

Well folks,

My baby is running so well that last Sunday I was invited by the Racing South West, a group of automotive aficionados who tends to be a younger, Tuner crowd, but who also get along well with many car enthusiasts. These folks remind me of a younger self, for while in the Military I owned a 1976 RX-3SP (these days are hard to find, but worth around $30K-$35K). The plan was to meet at the Santa Ana Casino on Highway 550, and head towards the Jemez Pueblo, Jemez Springs, and eventually to the Jemez Caldera Valle Grande view spot
http://static.howstuffworks.com/gif/scenic-drive-in-new-mexico-jemez-mountain-trail-gax800.jpg

I filled the Vette's tank, reset the trip-o-meter to "0000", and then headed out to cruise with as group to Jemez Springs. After a two hour lunch stop at the Springs, this rolling car show headed towards the caldera on highway 4 and highway 126.

I had a late model Super Supra in front of me, and throughout the group several Mustangs, a few Corvettes, and I even saw a Mazda 3Speed rumored to be in the 11's second 1/4 mile time slips. Gail had no problem keeping up with the few daredevils out in front, or even navigating the switchbacks of the Jemez Mountains and Bandolier National park. I was not drag racing her for short distances, mind you, but I kept her at a very good clip.

After the group shot, smaller groups decided to take some more road turns, but here, that cannot be helped, since it is the only way out to freeway systems either towards Santa Fe or towards Highway 550, so I took the Santa Fe route, and it added an hour to the trip, but the views could not be beat, and besides relatively strong winds (a by product of New Mexico's spring season), the weather and su set were beautiful.

I put about 200 miles in the round robin, and when I came home, I noticed that the tank was about half way, and although It was hard to contain my excitement on what this could mean to Gail's mileage, I waited until today to fill her tank, since on Fridays, I either take her or the Acadian to work with me (weather permitting).

So I stopped by the Phillip's 66 in the north-west side of Albuquerque (Alameda / Highway 528), and when I filled the tank, it came out to 10 gallons, and when I calculated it, the mileage render by my beloved Vette was a 20miles/gallon!!!! Woohoo!!! I am stoked!!!

 

[bill81vette]

That great Gerry!!!!!

 

[LT4man]

WOW!

Gerry, that is so cool.........

And to think that folks like to slam the late model C3s!

See, the General really does know how to design a car (Vette)!

SAVE the WAVE!

 

[Peer81]

That is great Gerry!
Is that with a 200R4 or the 350C?
I want to do the same next week (with a 200 mile trip).

Greetings Peter

 

[GerryLP]

That is great Gerry!
Is that with a 200R4 or the 350C?
I want to do the same next week (with a 200 mile trip).

Greetings Peter

Yeah Peter, the 200-r4 still is her new legs. But with the mods and what not, she was only giving me 14 or so per gallon, but now she's better than stock mileage (while stock, she used to give me 17/18 per gallon). Heck, If I were to go back to her stock differential ratio (now it is 3.31:1), her freeway mileage would likely to improve, but her low end of power range would suffer.

LT4Man, Wow is right....verbatim from my lips.... if for nothing else, the late model C3's continue their popularity with the general public, and you are right, for the first 148K miles, she brought me back home with a minimum of maintenance (tires, brakes, oil, air cleaner, and only one exhaust replacement. Since then, I the on-frame restoration was on going for 6 years, and at a cost of approximately $10K dollars, and she's in renewed spirits for the road again.

Bill, thanks. Hey, you k ow how she was leaking tranny fluid in Effingham last year, well, it was a dual problem. One was that the case plug for the lock-up solenoid was cracked and it leaked...and the other....and the other...:ugh...it was me pouring in quarts of hydraulic fluid everytime she was on the add mark, and not realizing that from the add mark to full mark is only 8 OZ's on this tranny...:L It is so embarrassing.