coppercutlass

Guys I have been trying to dial in the edelbrock 1405 on my olds powerd 77 Pontiac Bonneville. Idle is great , no studders, no bogging etc etc. my only problem is the Idle drop. I have to have my base idle about 800 rpm to keep the idle about 500 ish in drive. I have tried multiple timing settings , ported , unported vac. source for the adv. and changing the idle mixture. Pretty much no change at all. Very very minor. It does not like a lot of timing at idle so I'm starting to lean towards a converter that's way tooo tight as I have tried a variety of changes.

keep in mind this whole engine combo was at one point in my 72 cutlass but with a 2200 stall . I'm starting to think even though its a very mild build it needs some stall. The exhaust is a bit more restrictive than in my cutlass .

dragline

can you post a picture of the engine, there may be something one of the members can spot. also if you pull a manifold vacuum line off, does the idle go up or down?

coppercutlass

Yes. I have done ported and un ported vacuum source. The idle goes up and so does the timing but it dies when you put it in gear. Which makes me think its the torque converter. I dont know how a picture would work. I tried less timing and that didnt work either as the engine does not respond well to anything under 10 degrees initial.

olds 307 and 403

Some of the factory converters stall really low for sure, my current TH350C stalls really low. What timing are you running at idle? Points or HEI?

coppercutlass

HEI. It works well at 12 tried mant other settings

olds 307 and 403

I flash stall tested my stock TH350C converter, maybe 1400 RPM! No wonder it is a dog now. I find my cars like 1000+ RPM in park to have acceptable idle in drive. I always see at least 250 to 300 RPM drop in gear, both manifold vacuum. The stock cam and converter 260, the throttle shafts are probably very worn out on the dualjet, drops about 400 rpm. The 260 runs a very aggressive timing curve, starts advancing at 600 rpm. The Qjet was rebuilt with throttle shaft work and a custom tune on the 350 in the 70S. The timing is less aggressive on the 70S, it was maybe slightly better with the 2300 flash stall converter but still a good drop, around 300 RPM.

coppercutlass

I dont remember the idle drop when this engone was in my olds but my 355 i just sold would drop maybe 150 rpm but i had a 3500 stall. Based of what you told me seems like my converter is the issue . I just wanted to confirm it. I got a converter from a friend im going to put on.