This is all about my 17 year old son’s high school senior auto project from last June when he graduated. He has dreamed of owning a Camaro sinse he was a little kid.

In October of last year he bought a 91 RS with a 305 with a stock 700R4 Trans. The car was all stock with 90k miles on it. He pulled the engine and replaced it with a 350 (from a Chevy 2500 passenger van)that he re-built and he had it punched and stroked to a 383, 9.7:1 pistons a fairly hot cam (I don’t know the exact specs), an Edlebrock dual plane manifold and a Holly 750 and headers. He is using the stock 700R4 trans with a 2500 stall converter. He changed the rear end out to a posi and disc brakes. The timing seems to be set correctly. The fuel pump is a Holley electric. It shows 7psi at the carb. That seems low to me, but I’ve been out of the game for so long now.

Here’s the problem. The engine starts and runs and revs good, but won’t idle below 1000rpm. If he adjusts the idle over 1000rpm to keep it running and drops it into drive it dies. It just won’t idle in drive. The carb seems to be adjusted according to the manual. He can drive it, but he has to ride the gas and brake and we all know that’s bad. The car has no guts in drive, but in 1st it hauls butt.

I don’t know where to go from here. My Camaro was a 67 302 in 1975 and it’s been so long I don’t have the skill or knowledge to help him. He is out of school now and his shop teacher kinda pushed him out the door last June so he’s no help.

This kid has so much time, effort, sweat and money in a car that just won’t run for him. He starts Triton University in the advanced auto program in a few weeks and he is interning at our local Chevy dealer. Even the mechanics there are at a loss. He is starting to get discouraged and he is a really decent kid. I gotta find a way to help him figure this car out.

Any guidance would be greatly appreciated.

Dave

we're gonna need those cam specs... find em if you can.

Off the top of my head, it seems the engine needs more initial advance to be happy idling at a slower speed. This could be as simple as moving the vacaum hose for the vac advance from "ported" to "manifold" vacaum.

Where exactly is the initial timing set now? (with the vac advance disconnected.)

A 91 would have come with either a computer controlled q-jet or fuel injection, and may have come with a computerized hei without conventional advance mechanisms at all. Can you verify what's in it now for ignition?

On the trans, your comments make me wonder about 2 things. First, is the TV cable properly connected and adjusted? This is vital with these transmissions. Second, if the original computer is not there, how is torque converter lock / unlock handled? Is it possible the converter is locked all the time? That would account for many of your problems, in fact, if the converter is always locked AND the TV cable is not connected, that could account for all your problems.

Vacuum problem? Came with power brakes, cruise control, tank vent vacuum system, etc.??? Yeah, bet somewhere the vacuum system got messed up and unballanced, Between PCV valves and distributors with vacuum advance perhaps?? Hooking up that 750 and using all the right ports at the right time in the right place might have caused some headaches?? Same question, was a modern one replaced with older model HEI and vacuum advance?

No vacuum in use for tranny right? I know the factory doesnt use it but you or he didnt ADD a vacuum switch for the lockup system or anything right?? Ditto on the TV cable problem. Converter system would have to have been installed for a Holley. Special bracket on intake and cam on carb for TV cable.

The hint being that in DRIVE there is a problem but in first there isnt??

I am probably way of many bases but if you havent checked most of the above, better think about some of these. Dont drive this car like this, it'll blow the tranny.

I am with the rest of the other post. Most of your problems could be in whatever adaptations were made or not made in the installation.

Not enough stall?

What do you mean "Not enought stall". I have no automatic experience. back in the day, my day (the late 60s) my 67 RS was a 4 speed Muncie.

A converter with too little of stall will tend to work against the engine more because it's more efficient at a lower rpm. With a higher stall it will slip more at idle which will let a larger cam or rougher engine idle better. Just theory, but it's a general concern when dealing with large camshafts in automatic trans vehicles. Maybe it's pulling it down too much.

Or maybe try cracking the secondaries open a bit. ???

Time to go to bed. :)

If the car died in park or if it died in neutral I would say that it was timing or a disconnected vaccuum line BUT I had the same exact problem when I put a strong 383 in my camaro with a 700r4 tranny. Definately sounds like a problem with the CONVERTEVER. My car needed at least 2400 stall converter. So first things first. What brand converter do you have? Some converter companies are not TRUE STALL converters. Meaning they will advertise a certain stall speed when in fact it is not the case. Second, make sure that it is not locking. There should be special wiring in a 700r4 that will lock and unlock the converter. If it is locking right off the bat it will put too much of a load on the motor and will drag it to a halt. and Third, MAKE SURE THAT TV CABLE IS ADJUSTED PROPERLY!! This is vital to the proper operation of the tranny in all aspects. There is a nice article on the BOWTIE OVERDRIVES site that explains how to set it up in detail. Using a PRESSURE GAUGE is the only way to have it dead on.
If you had a standard in the car Ill bet any money that you would not have this problem what so ever.

GOODLUCK!!

I got the cam specs: :

Part Number: 113841 Grind Number: F-278-2 (REPLACES CC-278-2)

Engine Identification:
Start Yr. End Yr. Make Cyl Description
1957 1987 CHEVROLET 8 FAIR IDLE, MODERATE PERFORMANCE USAGE, GOOD MID-RANGE HP, BRACKET RACING, 3400-3800 CRUISE RPM, 10.0 TO 11.5 COMPRESSION RATIO ADVISED. BASIC RPM 3000-6500
Engine Size Configuration
262-400 C.I. V

Valve Setting: Intake .022 Exhaust .022 HOT

Lift: Intake @Cam 320 @Valve 480 All Lifts are based
on zero lash and theoretical rocker arm ratios.
Exhaust @ Cam 3334 @Valve 500
Rocker Arm Ratio 1.50

Cam Timing: TAPPET @.018
Lift: Opens Closes ADV Duration
Intake 29.0 BTDC 69.0 ABDC 278 °
Exhaust 82.0 BBDC 26.0 ATDC 288 °

Spring Requirements: Triple Dual Outer Inner
Part Number 96877
Loads Closed 126 LBS @ 1.850 or 1 27/32
Open 304 LBS @ 1.400
Recommended RPM range with matching components
Minimum RPM 3000
Maximum RPM 6800
Valve Float 7400

Cam Timing: TAPPET @.050
Lift: Opens Closes Max Lift Duration
Intake 10.0 BTDC 48.0 ABDC 109 238 °
Exhaust 63.0 BBDC 5.0 ATDC 119 248 °

that cam should be able to idle at 750-850 rpm pretty easily.
Did you get any info on the trans and ignition?

its a cap and rotor im betting because I had a cracked cap before and it would idle ok till it was put in drive then sputter and die.

I think the convertor is locking whenever the shifter is in high, but it's just a guess, need more info!