[65gto69]

Hi Guys,

Have a technical question that I hope someone can help me out with, I just can't think anymore and feel I covered all the bases but must be missing something because the engine does not stay running.

Info on car:
65 GTO
68 Pontiac 400 30 over, trw pistons, total seal gapless rings, 58-62 forged rods polished
68 #16 heads ported, polished, bowled, 1.65 steel rockers
65 distributer, new accel heavy duty points and condenser, accel super stock coil, new acel 8mm plug wires, new ac spark plugs gapped at 30
crane cams flat hydraulic cam around 560 lift w/1.65 rockers, I think 308 duration
timing at 34 degrees, idle between 800 and 1000 rpms
65 stock mechanical fuel pump, original from 65 has not been replaced as long as i have owned it, since 1985

Have tried many different intakes: offenhauser 2 four intake with 2 new edel. 600's, holley street dominator w/ new edel. 750, & rebuilt holley 750 dp/df/mechanical, & 65 tri-power setup.

Hope that is enough info, here is the problem, car idles great, starts up very quick, but when going for a drive when you are coming to a stop, the car stalls. It will start back up no problem, but stall again as soon as you come to a stop.

What do you think my problem is. if you need anymore info please let me know.

Thanks for all the help
Mark

[65gto69]

Hi Guys,

Have a technical question that I hope someone can help me out with, I just can't think anymore and feel I covered all the bases but must be missing something because the engine does not stay running.

Info on car:
65 GTO
68 Pontiac 400 30 over, trw pistons, total seal gapless rings, 58-62 forged rods polished
68 #16 heads ported, polished, bowled, 1.65 steel rockers
65 distributer, new accel heavy duty points and condenser, accel super stock coil, new acel 8mm plug wires, new ac spark plugs gapped at 30
crane cams flat hydraulic cam around 560 lift w/1.65 rockers, I think 308 duration
timing at 34 degrees, idle between 800 and 1000 rpms
65 stock mechanical fuel pump, original from 65 has not been replaced as long as i have owned it, since 1985

Have tried many different intakes: offenhauser 2 four intake with 2 new edel. 600's, holley street dominator w/ new edel. 750, & rebuilt holley 750 dp/df/mechanical, & 65 tri-power setup.

Hope that is enough info, here is the problem, car idles great, starts up very quick, but when going for a drive when you are coming to a stop, the car stalls. It will start back up no problem, but stall again as soon as you come to a stop.

What do you think my problem is. if you need anymore info please let me know.

Thanks for all the help
Mark

[STripleduce]

Do you have power brakes?If so I would guess the diaphram is bad and loosing vacuum when the brakes are pressed causing the engine to stall.

[65gto69]

STripleduce,

Yes I do have power brakes. It is all original from 65, nothing replaced since I own it. Very interesting, never heard of that before. Is there a test that i can do before going out and replacing an expensive part that may not fix the problem?

Mark

[pchris]

Vapor lock?

[Lerry: The Body Ventura..]

If it has a emergency brake, stop car with it and see if it is what Tripleduece says it is. It sounds like carb to me? Even though you've had numerous carbs on there?

[STripleduce]

Take the line off at the booster and plug it then try to stop,the brakes wiil probably feel harder but if it doesnt stall after that then you found it.Youu may even notice a change in the idle speed as soon as you plug it.

[65gto69]

STripledeuce,

I will try the test in a week or so but I was thinking. If it was the power brake unit, wouldn't I have the engine stall problem idling and hitting the brakes? Just wondering, don't understand what the difference would be idling or driving and why it only happens while driving and coming to a stop.

Thanks for the help
Mark

[Lerry: The Body Ventura..]

That's why I think it's sounds like carb. When slowing down, the gas is sloshed forward. Causing starvation or your drowning it? What's plugs look like?