I am working on a 17081228 (1981) Q-Jet and it is missing a piece- the plastic "well filler" or "well insert" from below the solenoid ECM connector. I am not a Q-Jet expert so I need a little guidance here...

This carb is a E4ME electronic unit.

I have been told that the purpose of this piece is to keep the volume of fuel down to match that of the other electronic carbs which had another device mounted in the same cavity, which this carb does not have/use. I have worked on other carbs (M4MED) which do have a device in the cavity, so I know that much is true.

Anyone know if the absence of this piece is critical to proper carb operation?

Tom

 

I think thats some kind of baffel. Someone may have removed it in order to increase fuel bowl capacity. Ive heard of trimming the baffel, but not throwing it out all togeather.

 

Tom -
You can run just fine without it. Not all the carbs had the liner installed: I have disassembled virgin carbs that had no liner at all in the cavity. I have not noticed any difference in performance with or without the liner, and I have tested carbs on my engine with both configurations.

 

hey tom.. i'm guessing this is mine... so i have an '81 carb on an '80 vette?? Strange....

thats why i was all confused b/c i thought 1980 was the last year that wasnt comuterized. maybe we should take a look if all those plugs go somewhere, or at least see what the heck is going on under the hood.


[Modified by Jenny, 8:38 PM 1/8/2002]

 

Okay... we'll not waste time trying to replace it. Thanks for the info.

Jenny... yes... this is your carb. Since you have an automatic and A/C, according to my sources, you should have a 17080202 (190 HP) or a 17080228 (230 HP).

The 17081228 is listed for 1981, 190 HP, automatic.
Clem brought this to my attention.. I completely missed it on the first pass. (Thanks Clem)

There is some "debate" about what constitutes an "electronic" carb. The "E4" series carbs had a variety of combinations of electric gizmos on them... they were used in other vehicles (including trucks), not just Corvettes. From a pure sense, none of them were an "electronic" device... like a TV. They do not contain any "solid state" devices. Just coils and variable resistors. They just sent (TPS) or received (solenoid) signals to/from other engine management systems. I do not have reference materials for this question... maybe someone else can clarify this issue (i.e.- which years Corvettes had the E4 series carbs as opposed to the M4 series). Clem or Lars might know... they have a soft spot in their hearts for the Q-Jets.

This is probably why the first carb kit they sold you was wrong... it was probably for a 1980 carb-
The air horn (top) gasket did not match at all and could not be used.
When you asked NAPA for a kit for a 17081228... it was a match.

When you had your car over here, I looked at it in the dark, outside, freezing my butt off (my fault, should have been wearing more than a T-Shirt)... so I didn't notice if the wires were connected to the throttle position sensor, or to the solenoid connector. I need to take a closer look... so I will need to see the car again, or you can do some detective work before you come back over to help finish up the carb.

Something is definitelty weird here. But if your car has all of the wiring etc for the 17081228... then we should be okay.

Tom



[Modified by Tom454, 11:41 AM 1/9/2002]

 

Hi, all
Just a coupla thoughts, and I'll get outta your way here...

I seem to recall that Doug Roe's book refers to that well filler as something intended to reduce sloshing, and I also seem to recall that he says it doesn't work very well. That would line up with Lars' contention that it isn't necessary. I'm sure Lars is right, as usual.

Finding an E4ME on Jenny's '80 is a puzzle, unless the engine is (or was) and LG4, i.e., an '80 California car. I suppose someone might've swapped the 305 out for a 350 or something similar. I recall from Jenny's earlier posts with photos that the car didn't have a stock '80 hood; rather it appeared to be a late-to-mid-70's hood, with the higher center bulge. Could these things be connected in history somewhere? That is, might a previous owner done an engine and hood swap? It's hard to imagine why someone would want to put a stock '81 L81 engine into their '80 Vette inplace of the L48. Unless they got a real steal of a deal.... :eek:

Jenny, did you ever check to see if the engine numbers matched the car's VIN?

It's very hard to imagine who/how/why an E4ME could have been bolted onto an otherwise stock '80 L48. Without and ECM hooked up, the primaries would be running full rich all the time. Making it work right would require the ECM, plus various sensors including the O2 in the exhaust. All of that stuff would require either a lot of patched-in wiring, which would be obvious, or a new harness, which is a boatload of work.

This is interesting. I'd like to hear what it turns out to be. Good luck! :seeya

 

I'm having the same thoughts on that too. I have the LG4 still in mine. Jenny...what's the 5th letter/number in your VIN?

 

Gator-

The engine is not original, it is the late 350HO, 300hp (the casting #'s on the heads confirm this). The hood puzzles me too, but i didn't notice the disparity until after i bought the car; maybe clearance? My car does have a supplemental electric fan mounted to the radiator...someone told me it was an option from the factory? If i don't need all that electrical crap, its coming out when the 383 goes in. :yesnod:

It's a little frustrating, nonetheless, to deal with this stuff. i don't care about originality, i'll feel A LOT better once i do the 383 so i know EXACTLY what is under the hood. But i still love her, and for the price i payed, it was a steal.

 

It probably was a California car with the 305 engine and computer controlled carb. Whoever had it before Jenny removed the 305 and installed a 350 and L48 emblems and/or hood. Can you blame them?

Jenny, you might want to keep the HD fan if it gets in the high 90's in NC and you like using the AC. The HD fan went out on my car, and with 95+ temps at 70 mph and AC on, the needle would climb past 210. I'm sure that if I hadn't turned off the AC and slowed down it would have risen further. I've since removed the AC, and I'll be installing the dual Spals as soon as they arrive.

Mark




[Modified by 81vette, 5:56 PM 1/9/2002]

 

I thought that was an 81, but you were convinced it was an 80...hehehe. Mine has a ce carb on my 81, but is not a CA car. Last of the ST louis cars were mixes of whatever was going out the door. I don't think mine has the filler in it, been a while. Runs ok without it. :smash: remeber to keep those bolts torqued. :cheers:

 

According to my sources, the California emissions carbs (ce) were as follows...

1980 305 190hp A/T: 17080504 17080517

1981 350 190hp A/T: 17081218

The carb we are working on is a 17081228 which is listed as 1981 350 190hp A/T non-California.
I don't know how accurate my sources are, but it is not important at this stage of the game, although it is interesting/fun to discuss.

I believe the solenoid connector was hooked up... this obviously would be necessary to govern the fuel mixture. The only question I have is if the TPS was hooked uop... because it would run without the TPS as the TPS is a quasi "output" device which does not alter metering directly. I vaguely remember seeing the wires connected to the TPS. So, this would indicate that the ECM is present. The only way to find out is for me/us to look at the car, which we will do.

As Jenny says... it's getting poop-canned anyways so it's not a problem no matter what. All we are trying to do at this time is get the engine to idle smooth so it can be driven. The throttle body was severely worn, which I repaired, and since it required a teardown, Jenny bought a kit and we cleaned it up. I just needed to know if the well insert was necessary... and that question has been answered, so we are all set. All is needed is to complete the assembly, which Jenny will not let me do unless she can get her hands dirty too... typical woman. NOT!

Thanks to all who responded.

Tom

 

504 calif 305,WO/AC,AT 517 W/AC, AT 218 350 W/AC, AT

 

Tom,

Did your sources give you the CFM flow of the carb? 600-650cfm? I checked the VIN # on the car.. it is Chevy Corvette 1980 coupe L48; Power everything. I dont think its CE, as it's been an east coast car, as far as what I can tell from the history on it.

I think you coined a new term: $h!T-canned :D LOLOL. Anyhow, time for class. TTYL!

-Jen

 

Very interesting....

Jenny, I believe these carbs were rated at 795cfm.


Mark


[Modified by 81vette, 8:09 PM 1/10/2002]

 

all Q jets are 750CFM except for some 70s big block buicks,olds,and pontiacs. chevy never used a 800 CFM Q jet. the 800 CFMs have a primary throttle bore 1/8" bigger than the 750 CFM. :chevy