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Topic Review (Newest First)
12-19-2010 07:32 AM
not2old4speed The carb. he is talking about has to be replaced with the same type, I think it is a 4EME4,on the right side of the carb.there is a plug(white) with 4wires, this is the throttle position sensor,it sends a siginal to the computer,which in turn controls the timing,the computer then sends a signal back to the carb,in the front of the carb,there is a blue cap that has 2 wires,this in turn controls the air/fuel mixture and the EGR valve.The 4EME4 is a 750cfm,if he uses any carb other than the one that is on it, he will have to replace the dist. as well.Having gone through this, I can tell you it is cheaper to replace the carb with the type that he has on it now.
12-19-2010 12:47 AM
Torque454 I would put on a early 70s q-jet carb. Something with little or no emissions crap on it. If you can find a 1 ton with a 350 in it or something, that carb would be awesome. A 1 ton would have "heavy duty emissions" (which didn't get all that emissions crap).

My 78 suburban had a 6800# GVWR which meant it qualified for heavy duty emissions. The carb on it (although it was a 454) had one vac line going to the distributor, one to the PCV valve, one to the air cleaner (two if you count the breather tube from valve cover to the breather) and then a short one that went to the choke, which was attached to the carb so it was like a 2" section of hose, almost not even worth mentioning.

It was very simple. It really wouldn't need any vacuum lines at all to run well but currently i do have the distributor and PCV valve hooked up.
12-18-2010 10:27 AM
not2old4speed To save you alot of hassels, replace the carb.( $489.00 from advance auto for a rebuilt one from cardone, Va. prices) or you can go another route. I ran into this issue myself with my 87 305 Camaro. I replaced the intake with a Edelbrocke daul plane intake,1406 Edelbrocke carb.(600CFM) and a Accel dist. You can use the stock brackets for your TV cabel& gas. The elect. choke is the same wire. I would be happy to email you some pics. of my set up.My car passed a Va. state inspection without running a EGR valve. your check engine light will stay on, I removed the bulb.If you would, you can email me at webman8@cox.net,will be happy to answer your questions.
04-02-2007 07:16 PM
fast68 all G20 are 5 lug

G30 are 8 lug

its not the same as C series

no TBI til 87


good luck
04-02-2007 01:32 AM
dieselcruiserhead I checked and its a CCC carb, not a TBI... The "carb" on the emissions diagram is definitely referring to it as a carburetor not CARB, C.A.R.B., though...

What are your suggestions...?

We have no emissions in this county, I want it to be basically as reliable as possible, but I actually do care about emissions at least with this thing mostly for resale if we ever get rid of it... At this point mostly interested in mileage... Funny I am on my 2nd frame off but I know so little about carburetors its almost embarrassing...

Would you guys fix/rebuild/replace this CCC carb, bolt it on and run it, or slap on a 70's Q-jet or something like that to replace it...? I have this posted on one of my land cruiser boards too and they are saying toss the CCC, and I'll probably need to find a non CCC HEI as well... The HEI is 1 wire.. I don't mind doing any of that stuff, but want the best with honestly the least work for this one.. Don't mind the work, just don't have the time right now and don't have too much spare $$ right now..
04-01-2007 04:01 PM
T-bucket23 If it is a mechanical pump, it is a computer controled carb. If it hasnt run in 10 years I would not be surprised if the choke is stuck.
04-01-2007 03:57 PM
Blazin72 That CARB you're referring to might not stand for carburetor. It might mean California Air Resources Board, or C.A.R.B.

As far as what you have. Even though there are electrical lines connected, it could still be carbureted. There were electronically controlled carburetors.
04-01-2007 03:47 PM
dieselcruiserhead Was just talking to a friend who knows more about TBI than anyone else I know and he says he's never seen a TBI with a mechanical pump. Also, the emissions sticker has a diagram of all of the emissions equipement and refers to the TBI or Carb as a "CARB." Also it says its California compliant. I figure they are all probably 50 state legal back then but thought I would mention...

So I am still confused whether its a late model carb with some electronic components or whether its a TBI...
04-01-2007 03:44 PM
dieselcruiserhead
Need some help with 1986 GM 305, TBI or Carbed???

Hi Guys,
Just scored a van last night, 1986 305, 700R4, G-20 model van but it's only 5 lug wheels and a 10 bolt in the rear... ? Only $350 and 67K original miles and actually has a pretty good body (minor surface rust) and interior. Not sure what I am going to do with it, maybe put the setup in something... I am actually psyched to maybe have as a van as I like that setup (the smaller motor, faster gearing and the OD for cruising)...

Got it so cheap because it has been sitting for 10 years.. So I took my time, even changed all the fluids even though they all look pretty good, and it fired right up.. Only thing is that, whether its Carb'd or TBI, it is dumping fuel down, can borderline almost not even run because there is too much fuel... I'm sure the sitting was not good for the fuel system..

I was under the impression that TBI started in 1987.. But on this van, even though it is an 86, if it is TBI, it has some clicking and electrical harness plugged into the carb/throttle body... Has an O2 Senson off one of the manifolds, and what looks like a heat riser on the pass side manifold. It is a van so a little hard to get in there and see for sure, even with dog house removed.. It has a HEI, but I know these came on both carbed and TBI models.. It has a mechanical pump, but a metal line from the pump to the carb/TBI unit that looks like it might be higher pressure than the normal carburetted pressures... I thought TBI were electrical pumps for some reason. Then, I found something that looks like it probably is a computer under the driver's seat...

So it is starting and running, but again literally dumping fuel. Almost as soon as it starts. I am wondering if it has an overfueling setting for cold starts or something like that that it is stuck on?

Do TBI units go bad? Are they interchangable, all years? This one looks different than the one I have seen on a '90 4.3 V6... I have a friend with a few V6 TBI units lying around. These are probably the wrong size / rating for the 305 V8 TBI? I guess my options are go to the JY and find a 305 and pull the TBI unit off that and bolt it on is probably easiest?

Thanks guys,
I really know little/almost nothing about these...

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