Stalls when put 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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Is there an EGR valve still on the engine?

If so, it might be stuck open or have a direct source of vacuum to it. Also, you mention it runs better with the vacuum advance disconnected, try retarding the timing a bit.

I hope this helps?

Refinish King

Reply to
Refinish King

Nope, EGR system is long since gone. As far as the timing goes, if I retard it any more, it dies.

If I spray quickstart (just a mist>Is there an EGR valve still on the engine?

Reply to
BlazerMaro

is the carb new? Used? Rebuilt?

Reply to
Brian

Reply to
BlazerMaro

Who gives a f*ck what size your "valves" are? The only "advance" you should worry about is the $25 advance payment to the tow truck guy to haul that piece of junk away. I mean, COME ON! Everyone knows that GM six cylinders are crappola. And you tried to hot rod one? You must be a glutten for punishment. Now you are getting it. Even Camaro guys won't admit that they drove a 6-cyl turd mobile. Sheesh, I'd hate to be in your family.

Reply to
Axel Foley

Loosen the valve lash a bunch to see if a "smaller cam" helps.

Reply to
Axel Foley

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