me and a friend are about to dive into rebuilding the carburator on his 86 oldmobile cutlass's 2.8. its one of those really funky electronic feedback type with a vaceum secondary. his dad wont let us toss the carb and get one thats not electronic, for some reason about it messing with the ignition. but does anyone have any trics for getting one of these carbs to work better?

 

Pull it, take it to a parts store, swap it for an aftermarket or if you're bucks up take it to a dealer and swap it for a GM rebuild.

If you must do it yourself, do you at least have a rebuild kit yet?

 

yeah, and we tore into it today. didn't find much inside of it except a little varnish. we cleaned it and installed the new parts. then went to the junkyard and got another carb to make sure we had the 300 linkages on it hooked up right. we also discovered that the car was supposed to have a little heater under the carb to help evaporate the fuel. so we got that too along with a couple of vaceum lines that the car needed. we didn't finish today, but everything went good.

my friend ryan would like to go to a regular carb, even if he had to rebuild it, but his dad is stuck that carbs suck, ditto for multi port injection. throttle body is the "best" way to go.

 

My thought on this is, just get a rebuilt one. You need special tools to set this carb up correctly. Good luck.

Dave P.

 

The problem is that the computer controlls the metering of the fuel in the carb, and also the ignition timing. The good news is that you CAN upgrade the 2.8 to HEI (not the CCS system), and run an aftermarket carb, it will probably run better and get better mileage too... Tell his dad he's an idiot and prove him wrong.. I mean if you guys are willing to spend your own money on it, and his dad isn't paying anything into the parts, then tell him to get bent.

 

Those carbs look simple,but if you arent sure of yourself buy a rebuilt carb.You will also need a special tool to adjust the idle mixture.
Are you sure that the carb was your problem?

 

i wasn't completely sure if the carb was the problem or not, but he already had the kit. we will have to do some looking into the hei system. something noteworthy of was that the kit had nome stuff to make the choke adjustable. his father is truly worse than he sounds, one of my purposes inlife is to prove him wrong. i have before. i'll do it again.

 

With the right carb and intake that 2.8 can be a good engine. It's small, and is real good on fuel. IT's just a matter of getting that carb to run right... Is it a 2bbl? or a 4bbl? Get me the numbers and I'll see what will match up.

 

I'm trying to figure out which Olds Cutlass had a 2.8 in it back in '86. The Ciera had a 3.0L, and the Supreme had a 3.8L. Guess it doesn't matter until it's time to look at aftermarket carbs 'n stuff.

 

Polar, it's 2.8 go to the partsamerica site and look it up.. I'm assuming his vin is "X" seeing as how it's a 2bbl.

 

yep- means it's probably a Cal Emiss car (more junk to deal with).

 

its a brougham, 2.8. it 2bbl, but its more like a 1 bbl with a secondary (mechanical too, even sounds decent when it opens up) its also an auto, although i doubt there was any manuals. i have only rode in it once since we got the carb back on, so im not really sure how much performance has been regained. but my friend says that it still likes to die when he accelerates. but i do know this thing should have way more power. when i drove it it felt gutless compared to my 2.3 ranger.

 

Take it to autozone, and have them pull the codes. It's possible that one of the sensors in the carb is bad. It may or may not trigger the CEL. If it was mine I'd scrap the computer altogether and turn in back to 1980 technology.

 

You have a Varajet. Hooray!

Anyway, that carb should have 3 connections on it. One is for the electric choke, one is for the mixture control solenoid, and one is for the TPS sensor. The problem with just removing the carb you have on it and using another one is the TPS. The computer takes input from the TPS (throttle position) and MAP and uses that to determine the ignition advance (some other things too, but those two are prime).

You CAN get a standard HEI distributor from a non-computer controlled car, then use a regular carb, that will pretty much disable any computer control. If the car still has the AIR smog controls, you might need to go ahead and unplug the diverter solenoids (electrical connections on the pump body).

Look for a distributor off of a 1980 Chevy Citation 2.8. It is standard HEI, no computer advance. 1981 is the first year they started using computers, so make sure it is a 1980 model.

If you can't for whatever reason swap to a non-computer carb, look at replacing the mixture control solenoid (the device with the electrical connector on the very front of the carb). They varnish up and fail with pretty good regularity. The Varajet seems to be a beeyatch to tune. If after replacing the MCS you still don't seem to be getting good mixture control, remove the float bowl vent screen, and you'll find the mixture screws. There might be little lead plugs over them that you'll have to remove.

Other things to watch for: make sure the choke plate is open all the way when the car is fully warmed up, make sure the vacuum breaks on each side of the carb are connected properly (look at the vacuum map under the hood of the car), make sure your vacuum system is connected properly (these carbs are VERY sensitive to vacuum leaks).

People hear the words "computer" and "carb" in the same sentence and immediately assume it's this massively complicated system. GM's really wasn't that complicated, it just didn't age very well (actually, it was a pretty decent design, but it relied too heavily on vacuum and smog stuff and over the years when that stuff breaks, it tends not to be repaired, um, properly, and there comes a point where it's just more feasible to dump the original stuff and go with something more maintainable.)