can a cpu controlled carb be used without a cpu?

[79malibu]

do you have to have a computer to run the electronically run carb or can you rig something up. i'm talking about the cpu run rochester 4 bbl carbs that some of our cars came factory with. i was thinking of stripping alot of the cpu and emisions crap off of my 84 monte as i am rebuilding the engine/trans swap to a 700r4 and restoring the car. is it possible to rig the carb up to run right or not. otherwise i need to buy a carb. yes i will be using a norm vac run distributor.

i also ask the question because i have a beater 82/83 s-10 that needs a carb bad and old one is past shot. it has the crappy 2.0 engine and have trouble finding a 2 bbl carb that isn't cpu controlled for this s-10 doesn't have a cpu running stuff. my idea was to take a working 2bbl of a 2.8 v-6 and have it adjusted to run on the 2.0 but all the 2.8's were computer controlled and i don't have 1 to run it but can i rig it some how?

 

[KrisW]

No rigging, it will run without the ECM, but it will run bad. You either need a working ECM or an older, non ECM carb.

If you don't have the money for either of those, then you need to get creative and build an adapter to run a carburetor you do have. If you start with a 20 dollar aluminum piece from the auto parts store you'll have a good start.

I'd keep hitting the wrecking yards for a non ECM carb if I were you!

 

[Geesie]

It will not run properly without the ECM.

Case in point: My throttle position sensor stopped working on my CCC Dualjet. The power circuit did not work without the computer feedback from the TPS, so the carb never compensated for the huge vacuum drop with WOT and I lost all power at WOT. I couldn't climb hills without it sputtering down to 15MPH.

 

[79malibu]

carb

yea i figured that. there are no junkyards around me for 100 miles that have anay kind of non ecm small jetted carb for the s-10. iirc i have noticed on the 2.8 motor carbs that the only hookup from the ecm is the blue connector on the front top of carb running the metering rods i guess since its always clicking when motor is running. thought that maybe it just need power and would run without an ecm but i'll have to keep hunting i guess.

 

[85 Cutlass Brougham]

Find a competent local carb shop and have them go through it. The last one I had done was around $100. I am curious though, is it an Isuzu engine? I remember that they were used for a year or two before the Iron Puke 2.5 replaced it ( later to be replaced by a Cavalier engine!). If it is an Isuzu engine, try looking at Isuzu I-Mark's, P'up's and old Trooper's in the junkyard as a possible donor. You could also try to adapt a Carter YF-A from a L6 AMC, or Mopar of the late 70's too. There are a lot of possibilities here for a 4 cylinder carb if you are creative and the truck is a manual.


As for removing the computer, you need another carb. Get one off a late 70's Chevy for a Quadrajet as it will have all the same hookups, but without the computer. Mine is off a 1979 Chevy van.

 

[79malibu]

carbs

i already have plans for another non ecm carb for the monte.

now the pickup, its truly a junkyard beater. it is a junkyard frankeinstein. someone fixed this up with pieces from other vehicles. must surely have over 250k on it. rear is out of a blazer, not the original 4 speed, but the motor has been rebuilt at one time. the 2bbl rochester is totally shot. the bushings are so out that i think can hear it sucks air through rods. the rods are so worn that they have rubbed the majority through themselves and other linkage except for throttle cable. the choke pull off is messed up at the least to say that i got a piece of 1/2'' gas line stuck down here throat just to keep the choke backed off. never took the time to rig a manaul cable to it but the gas line fix has worked for over 3 years now i can say :lol: to top it off the 2nd bbl will not open at all even when off motor. linkage is screwey so i dont hardly go past half throttle. i asked a couple of guys and they said find another carb. whats shocking is that they want $350 for a factory replacement for this 2.0 4 banger!!!!!!!!!!!! :shock: i bought the pickup for $45 bucks cause it wouldn't start.(locked starter but pop clutch while getting pushed fixed it ) i just need the dam thing to idle, sucks using 3 pedals while town driving with 2 feet so it don't stall. when it does idle it usually runs so fricking high like 3k then cuts out. been through a kit and float and can't figure it out. only way i have been putting up with it for last 4 years or so is because %95 of my miles are highway and if i can keep moving it runs great. i belive the 2.0 was an isuzu motor but all the older vehicles that it came on are extinct up here. scrap yards are selling dam near everything off left and right cause the price of steel is up.

but thanks you guys. especially for the time i just wasted of yours!?

 

[KrisW]

You have an Isuzu engine.

This carb is for 248 bucks and you can get it here:

http://www.partsamerica.com/productdeta ... 26&PTSet=A

It's for a 250 inline 6 chevy engine from 79 or 80. This is the best one to use as a replacement and there is no ECM control over it.

Believe it or not, it will work well for your application. I did the exact swap on an 84 Isuzu P'up with your same engine. I had the exact carb problems you are having as well, including the secondary not opening up.

If you buy this carb and install it, you will most likely save over 250 dollars in gas and the carb will pay for itself the first year. You won't believe how much better the mileage is with this carb!

Good luck!

 

[79malibu]

carbs

thanks, i just found the same thing for $180 listed now.