Hi all -

Carb needs rebuilding ....
I was crushed to learn that Lars no longer does the computer controlled carbs as he has
no way to test them once they are rebuilt.......:(

Anyhow, does anyone have a recommendation on who to use. I live near Atlanta, GA.
Or I can ship it out somewhere. I dont know how I feel about doing it myself.
I have Dave ( or is it Doug ) Roes book on Rochesters and have read it.....just never touched a carb before.

Anyhow - any ideas?....

Should I try it myself? ......or just start hunting for shops in town that do alot of carbs....

Thanks
Kevin


[Modified by ksems, 8:21 AM 4/23/2002]

 

Hi Kevin,
There's a couple of knowledgeable L81 carb guys here (Hi) who will hopefully answer your question. If you do it yourself, then get hold of a digital camera & take a picture of everthing that you take off & anotate it with relevant info such as how many turns to unscrew, position in relation to other parts & so on. Label & separately bag each part. It will take time but will make the build up so much easier.... & you won't have any bits left over at the end!!! I'm probably teaching my Granny to suck eggs here (weird expression), but at least you'll get it back together set up the same as it was b4 it came apart & have a good starting point for final tuning.
My plan (as mine needs doing) is to get hold of a used carb & pull it apart b4 touching mine. That way I'd familiarise myself with how it works & what all the bits are. Once you've got the confidence (& know how not to break bits ;) ), then the actual job will be much easier. If the amount of parts & complexity of the spare carb scare me, then I'll know not to touch mine :)
Good luck
Paul

 

Hi, Kevin & Paul,

One outfit you might call is "Carbs R Us" in Mesa, AZ. (480) 461-1690

It's hard to know how much to encourage someone to tear into an E4ME. I had done many carbs before I went into mine, but I had never done a Q-Jet before. It is a complicated piece of machinery.

On the other hand, Doug Roe's book is such an excellent step-by-step reference, including a section specifically for the E4ME, that a reasonably careful (save the beer for after!) person with an eye for detail and the ability to RTFM! should have no problem. The most significant aspect of this is pointed out in Roe's book: The vast majority of Q-jets DO NOT require a complete tear-down and re-build. Generally, the service procedures they require are straightforward and simple, and in fact most of them can be done ON THE CAR with just the air horn removed.

[The biggest exception to that general rule is the plugs on the bottom of the carb - if they're leaking, like mine are, then the carb's gotta come off. The second-biggest exception to that general rule is the wear on the throttle shaft bores - if they're worn to the point that the throttle shaft moves back enough to cause the throttle blades to bind at idle, like mine are, then the carb's gotta come off to be reamed and bushed.]

I pulled my E4ME and did the basic kit rebuild (NAPA kit) plus sealed the plugs on the bottom. The rebuild went just fine and the carb and car run wonderfully. However, I've recently become aware that my carb has that throttle shaft bore problem, and apparently one or more of my "seals" on those plugs didn't hold, and it's leaking again. So... it will be coming off again soon.

Read Roe's book. Read the section on Q-jet service, then read the section on special procedures for the E4ME. Then go read them both again. Do you have the '81 Corvette Shop Manual? Read the section on the carb a couple of times.

About "Carbs R Us": I cannot personally recommend them, as I have not used them for service. I bought a kit from them to ream and bush the throttle shaft bores on my E4ME, but I haven't used it yet. I will be doing that soon, probably withing a couple of weeks, so I'll let you know how it works out. I do know that "Carbs R Us" is well known in the Southwest, and their name says it all.

Good luck, and e-mail me and UKPaul if you want to chew over it some more. :seeya

 

the problem is the solenoid. AC Delco does NOT make these anymore. After markets exsist, and mounting to the air horn is different. $75.00 or so just for the solenoid. I remeber reading about some carb shops that can rebuild, replate and bench test. I would search aound. A new one, still in GM system is about $1300.00, but these are NEW. :eek: I have a spare and had it rebuilt, it now resides with a lot of my other 81 spares. :smash:

 

Hi Gator :)
I've just seen 81VETTOMs post - $1300 for a new carb?!!! :eek:
After seeing that, I'd highly advise that you don't hand ream your carb body for them bushes. If you know somebody with a true running lathe then you could accurately mount the carb on the xslide & turn the chuck by hand while moving the slide towards it with the reamer mounted in the chuck. Or use a mill/whatever.
I've been RTMFing (over a beer) & the shaft is something like 60thou off centre, so you'd have to hand ream to that accuracy. If that isn't tricky enough in an oval hole, the shaft would have to be perfectly perpendicular to the bores, otherwise you could end up having to adjust the butterflys on the shaft to get each to open the same amount & still close correctly. Remember how much your T100 shook if you got the throttle slides out of sync with each other? (Or was it a single carb?).
Could you not send your carb off to Carbs R Us for the reaming/bushes & stick a spare on yours while the job is being done? Just an idea - but better safe than sorry.
Sorry about sounding so gloomy! I once had a pair of numbers matching crankcases turned into scrap by an engineer who reamed off centre (& the cheeky **** wanted paying for the job!!!). Reamers can be dangerous tools!
:cheers:
Paul

 

I rebuilt mine, it was the first carb I rebuilt and I had no problems. Take your time and clean it good. I would not recommend removing the idle mixture plugs or choke unless you need to. If you do decide to rebuild it, Lars suggests getting an Echlin (Napa) brand NitroFill float (not a brass float). And this page describes the tools/gauges for adjusting the E4ME, http://www.aros.net/~rbuck/tech/carbtool.html, these tools are still available at NAPA and the tools/gauges cost me about $30. You don't need the tools to do the rebuild, but I got them to make sure everything was set properly.

:cheers:

 

Hi, again, Paul! :)

Where are you reading about tolerances in the carb? Is that in Roe's book? Been awhile since I had mine out, don't recall seeing tolerances in there...

I bought that kit from Carbs R Us over a year ago, and didn't take a close look at it unitl now. First, it contains 2 reamers, not 1 like I thought. One is 5/16", the other is 11/32". Are the primary and secondary throttle shafts different sizes?

There are also 10 brass bushings (or at least they appear to be brass; I recall being told they were brass). They all appear to be the same size. I'll have to get the calipers out and measure them. If they are the same, then I must assume that it's necessary to use both reamers (???), first the smaller and then the larger, to get to the correct size? I know, it's silly to speculate and ask questions now, when all that stuff is sitting at home on my work bench and I just need to do some reading and measuring....

The reamers are about 6" long, with the end 1.5" or so having teeth, and the remainder of the shaft being smooth. Would you think you could put the reamer through the shaft bore, shank first from the inside, and then chuck it up? so as to be self-piloting? The kit is virtually devoid of instructions; the few terse statements and complete lack of diagrams don't tell me anything I don't already know.

later,
:seeya

 

High guys. I'm late to attend the discussion again due to too much time at work. :rolleyes: I have been into my E4ME a million times, have torn it apart end to end, put it back together, torn it apart again, and it works great. All that tearing it apart is how I learned how to make it run. I don't see any reason to get a rebuild kit. Take the carb off after the car has sat over night and see if there is a puddle of gas in the bottom of your intake. If so you need to seal up the fuel well plugs, if not continue on. Neither one is that big of a deal. Just standard Q-jet stuff up to this point. Now you have to take off the top. Once you have the top off Doug Roe's book should point you in the right direction. If your M/C selenoid is bad replace it. NAPA has them for not too much cash. NAPA also has the gauges to adjust your rich and lean stop, and tools to change the settings of them, but all you really need is the piece of tubing that is outlined in Roe's book. Replace your float while your here, they're cheap. Adjust you M/C selenoid, put it back together. If your mixture screws have the plugs removed, or if your motor or exhaust isnt' stock anymore, you may need to adjust the mixture screws.

I am using a bit of vagueness because until you get into more details on whether or not your motor is stock, and particular questions on working on the carb, it is hard to respond. I didnt' know anything about carbs when I started to learn this one, and now I have complete confidence with them. (at least the E4ME) I think you can do it.

-Justin

 

Hi all -

thanks for all the responses - KEEP EM COMING !
Im learning alot just reading what you guys are talking about back and forth.

Justin - the car is stock accept that I have installed dynomax Super Turbos and removed the CAT /replaced with a "test pipe".

Im going back and forth here - I feel confident that I can do it and then
I hear talk of stuff way "over my head "

I feel like giving it a shot though. :D

Lets hear more !!!!! More More More !!!!!!!!!!!!!!

Kevin


[Modified by ksems, 7:30 PM 4/23/2002]

 

I don't know that the mods you have are enough to need to adjust the mixture. What does the car do that makes you think it needs a carb rebuild? The mixture should be adjusted to suit the less restricted exhaust, but I guess it depends on whether or not you want to either buy an exhaust tester that screws into your O2 sensor hole, or make one and use your multimeter. But lets not get into that yet. Has the carb ever been worked on? There are 2 holes in the bottom of the carb on the front about 2 inches apart. Are there steel plugs in them or have they been removed?

 

If you choose not to rebuild the carb yourself go to this site and see what they offer.
http://www.nationalcarburetors.com/

I have used them 2X for E4MC's and the carbs have run beautiful out of the box. Just normal tweaking. So far no problems and with a lifetime warranty.

 

first and only carb i've ever rebuilt. i've had very few problems from mine. the biggest problem i'm aware of with these carbs are the throttle position sensor and sometimes the mixture control solenoid. i have doug rowe's book but never read it through and i've rebuilt my carb twice, once for bad TPS, once for crap in the needle and seat. i don't really know if you can truely screw these things up. i just got a kit, pulled everything apart and put it back together. works great. still makes 200hp (with 158k miles, but there are mods) and gets 20-22mpg on the highway.
if you do it yourself, just take your time. remember, nobody you pay to rebuild your carb is going to care as much about it as you do. if you decide to send it out, make sure it's a reputable shop. you may want to give holley a call. a while back i heard they were restoring vintage corvette carbs, holley or not.

 

Hi Gator,
I'll try to answer as best I can (as usual, I'm at work with the Boss man next to me, so giving a long reply can get awkward - this is why some of my posts read a bit strange!!!).
It would make sense to ream out the holes in 2 steps, as there is a limit to the amount of metal that should/can be removed with a Reamer, & you need to get a large enough hole so that the new bush will have plenty of "meat" in it. Hopefully the bushes are brass as it's sort of self lubricating (well, it's better than the original monkey-metal the carb is made of!).
Do the reamers have a starting taper or is the cutting part parallel? Is the shank of the same diameter as the cutting part? And do the teeth have a lead in at the end the shank is? All these questions! You may find that the manufacturer has been really kind & has made the shank of the 5/16" reamer the same diameter as the throttle shaft, with a lead on the cutters at the shank end. The shank can then be passed through the original bores as a guide to give you a fighting chance of getting positional accuracy by cutting as you said. In the same way, the shank of the 11/32" reamer could be 5/16" diameter. Lets hope so! Or they could just be standard off the shelf parallel hand reamers :(
I can't answer on the shaft diameters as my carb is bolted to the car which is miles away (& very close to firing up :D ). I'll check tonight if I get there (the weather is currently like mid-summer & we're sweltering, so there's an imminent visit to the pub looming :) ).
I just love kits that include reamers. Reamers & instructions seem to be mutually exclusive :lol: One thing I have found out is that you should never turn a reamer in the opposite direction to the cutting direction. Apparently it's a good way to blunt the teeth. But it also gives a nice finish to the hole (both bits of info are from 2 different engineers!!!). If you're only using it the once, though......
But, things are looking up as you've got 2 reamers in the kit, so with care & patience (& a lot of guts!) the job may be do-able by hand. Have you got an old carb that you could practice on? I've found that with reamers it's always best to do a "dry run" - especially in ovaled holes where the reamer may want to "wander" off centre.
The tolerance stuff I picked up in Doug Roes book. I'm not sure of the section or page number, but it made me think of how awkward it would be to hand ream.
If you've got access to a decent drill press with adjustable table, you're laughing(?). Rotate the table to 90 deg. Clamp the end of the stripped throttle shaft in the chuck & then pass it through the carb. Then clamp the carb to the table & lock the table so that the chuck (with shaft attached and the drill at the fully extended position) moves freely up & down in the carb. Then remove the shaft from the chuck & carb & clamp the reamer in the chuck. Hand turn it as you drop the chuck down & you should be reaming as good as spot on centre. I've done this with small end bushes & it's fairly easy - the trick bit is getting the work bolted to the table & the table locked in the exact position (beer may be needed - but only because the cans make good shim material!).
Another possibility:
Normally, with bushes, the usual course is to fit them & then ream them to the correct fitted size. So the 11/32" reamer could be for truing the holes up for the bushes & the 5/16" reamer could be for reaming the bushes when fitted (5/16" would seem to be a sensible size for the throttle shaft). I'll measure the shafts when I next "visit" my Vette!
It can get worse! I've just found a problem with my carb that makes reaming of the throttle shaft bores seem quite attractive in comparison (Bubba. Again) :eek:
I think we'd better continue this one via email - it's clogging the forum up & is probably really turning Kevin off of the idea of doing his carb himself :lol:
All the best (I'll email you when I've done some measurements),
Paul

 

install a non computer distributor, and get a 1904 edelbrock. I had less problems after I had the computer carb on my 81 rebuilt about six months ago, but I couldn't get rid of all of the problems.

to note: I passed emissions this weekend with the non-computer equipment, and although the motor is newly rebuilt,,,, emissions were so low that the guy had to retest it a second time. The non-computer equipment works great,,,, and you control how it flows,,,, not the 20 year old computer.

 

Kevin,
I'm feeling guilty about hijacking your post! ;)
As Justin(?) asked, are you sure the carb needs a rebuild & not just a bit of a tweak? My carb had been "worked on" when I got the car (the settings were all over the place) & after many posts on the subject & a lot of help from people like Gator & Dellanex ( :cheers: ) I plucked up the courage to have a "play". It's a piece of cake! Just measure exactly where the settings currently are (eg. mixture screws: turn in until the bottom & note the number of turns) so that you can always revert to the starting point. I ended up setting it up exactly as described as the standard settings. I've got no AIR, EFE, EGR, or cat & am running 2 1/2" dual pipes with Monza "mufflers" (ie more or less a straight through exhaust system). A few other tweaks such as high o/p coil are also on the car & the carb performs great at the standard settings. But, like Gator, I've got a lot of wear in the throttle shaft which is letting in air. There is an irregular idle on the d.side which I'm convinced is due to this wear (if I cover the end of the shaft in grease where the wear is, the idle smooths out OK). The odd thing is that I've just found more wear, hence a larger hole, on the p.side of the carb, but the p.side idles really nice. Weird.
I'd say "go for it!". Once the carb is off the engine it doesn't look as intimidating! The only reason I didn't pull mine apart was that I've pulled everything else apart, so if it doesn't start or run right I can rule the carb out as a possible cause (that + the fact that if I break/need something I can't just run down to the nearest Q-jet shop & buy a new one!).
:cheers:

 

I think mine needs some work becuase my car is getting pretty damp with gas around the gaskets on the outside and my intake is getting a little fuel on the radiator side of the carb....nothing real serious. Ive had the code for MCS sensor come up and go away....havent seen it in a while though.

I just have the idea of cleaning it all out .....making things nice and tidy....

80,000 miles , it probably is on its way out - yes ?

 

plus - everything else on my car works perfectly so I dont have anything else to do with myself......

yeah right :D

 

Just give it time..... :D

Kevin,
My carb was seeping fuel (judging by the stains all over it & the manifold) & I found that all the screws for the air horn, etc were loose (got about 1/2 turn on each). Obviously the gaskets had compressed over time & I don't know yet if tightening it all up has cured it. Could be worth checking. There were also a few screws underneath that were loose, but that involves taking the carb off to get to them. And once the carb is off, then......well, you know ;)
Paul

 

Here's a fairly easy way to check your mixture control selenoid. I used this method after finding that I really don't care for the dwell method.



-Justin

[Modified by Dalannex, 8:08 AM 4/25/2002]


[Modified by Dalannex, 8:10 AM 4/25/2002]