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Cannot stay running in gear

Hello all...I recently completed a 2.8-3.4 swap in an S-10, and I am having problems with the motor stalling when I put it into gear.

Here are the parts:

3.4L (from donor camaro, overhauled w/new rings & bearings, block tanked/honed.) w/stock heads & valves; 1.52 roller rockers Comp Cams High Energy 260H camshaft; 260 duration/440 lift. Timing chain/gears to match. Holley 0-8007 390CFM 4160 carb (Throttle plates drilled with 1/16 holes) Edelbrock TorkerII tunnel intake Stock HEI dist w/MSD 6AL box; overhauled & w/new ignition module Holley "Red" electric fuel pump w/regulator set to 5.5PSI Mated to a stock 700R4 tranny.

I am pulling 19.5in of vacuum @1500 rpm, rock solid. All vaccum lines were replaced with swap, and have gone over every line w/carb spray looking for leaks. Nada.

Compression is great.

Ignition system functions perfectly.

I cannot get it to idle reliably lower than about 1200-1300 RPM; I expect this is a result of the cam. It is happiest above 1400. It runs very nicely through the rest of the RPM ranges, although it does seem to be slightly happier without the vacuum advance being hooked up, while the choke is on. Nothing major, just a very slight burbling. Mixture screws are 2 turns out.

I have drilled 1/16" holes in the throttle plates, it got quite a bit happier after I did that. I've tried cracking the secondaries a bit, and while it will idle a bit faster, it doesn't seem to make it any better. Still stalls when put into gear.

Any ideas what is going on here? I've run out, and getting very frustrated.

Thanks!

Reply to
BlazerMaro
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I am not to up on this swap (sounds like it will be sweet, but would the 4.3 not fit?) ,but I would guess GUESS...torque converter clutch? Or are the valves adjustable in that motor, ,and set too tight?? Just guessing here, but it may jog someone elses thoughts...

Eightupman

Reply to
Eightupman

you may need to get a higher stall torque converter. when you put it in gear the torque converter in trying to pull the engine down to what a stock engine would idle at.

had a similar problem after putting a gasoline engine in front of a tranny that was designed for a deisel engine. as soon as you put it in gear it would pull the engine rpm down lower than the gas engine could idle because a deisel engine idle very slow.

Reply to
digitalmaster

Sounds like you need a good stall converter in the trans. When I bought my '71 T/A(auto trans then) it had a really radical camshaft but a stock converter and it would kill when I put it into gear unless the engine was fully warmed up.

Reply to
Dennis Smith

I was wondering about the converter angle myself, but CompCams says that it should work very nicely w/the stock converter. I don't know very much about torque converters beyond what they do. Do any of you know a good webpage that explains the stall speed concept?

Reply to
BlazerMaro

Reply to
barrythedude - remove yer HAT and COAT to reply

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