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Discussion Starter · #1 ·
Hi everyone, I've got a problem that might be a simple fix or might not...

I've got an 86 cutlass and recently swapped the old 307 for a sbc and th350. I called ******* perf. and they set me up with a nice 3000 stall converter. When I go from park to reverse or neutral to reverse, it kills the engine dead. When going from neutral to drive, rpms drop a little and I have to give it a little gas but it doesn't stall.

The carb is a holley 4150 770cfm street avenger. I really doubt I have any vacuum leaks and the trans shifts very nicely in all three forward gears. I've been thinking the problem is tuning the carb, I haven't got the idle set properly in drive.... but would this kill it automatically when I shift to reverse? I also advanced the timing a good bit to see if that would help, but apparently not.

I asked around some tranny shops and they said the problem was I have a non lockup converter and it should be a lock up.... but would the trans shift fine going forward if I had the wrong converter?
 

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what trans did you have in the car before or is it the same origional trans that you installed another converter in? if so, does the drivers side of the case have an electrical plug with wires going into it?
 

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Discussion Starter · #3 ·
The original trans was a th200 and was scrapped for 4$, that's about as much as I could get outta it

The new one was actually in an 86 monte carlo which was primarily a drag car. It wasn't mine, just a guy who had a deal on a transmission (was selling his whole engine/trans to upgrade to a turbo sbc and 5 speed)

He didn't sell his converter as he thought he could reuse it - it was a nice nitrous holeshot - he had time slips that showed the tranny ran high 10's/low 11's on nitrous so it has to be in good shape cuz it still shifts

I'll look to see if it has any electric plug/wires but I don't think so...

I tuned my carb near perfectly this morning and it has good vacuum and starts right up, so the problem isn't vacuum or carb. I'm almost positive the timing is fine, it's a little advanced but not enough to hurt anything.

I checked the trans. fluid again and it's well above full so I'm going to let about a quart out and see if anything changes. Could it be too full and the pump has too much pressure so it's not engaging reverse? I don't know much about transmissions so any advice will help

Also the engine idles in park at 1600, in neutral at 1700-1800, and in drive at 800rpms. Is that normal? I've never heard of a car dropping idle so much...The cam is a comp cams 282 XE retro fit roller. The vac. reading was 18-19 at idle and about 10 in hg in drive/idle. It's a little low, but should be fine
 

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yea,that hole you pointed out is just for a jig that holds the case for assembly. thats supposed to be there. the electrical plug would be below that if it has it...
other than the vacuum dropping off everything you mentioned sounds fine. to me it seems that maybe you have a hole in the vacuum line or the converter isnt what its supposed to be. ive gott a 2000 rpm stall converter in my 700r4 and my idle barely drops 100 rpm. so, i would check to see if your bleeding off vacuum in the line somewhere from the manifold to the modulator, and make sure you got the right converter... gl
 

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1600 in Park and 1700-1800 in Neutral is too high. As tnsmith10 says, you need to look for a vacuum leak. Then get a timing gun and set your timing correctly. I've never had an automatic car with 1600-1800rpm in Neutral or Park, even my old "blown" car was never that high in Neutral. Try shooting for 1000-1100 rpm in Park or Neutral.
 

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Discussion Starter · #7 ·
hey everyone, thanks for the ideas... I fixed my problem. I bumped back my timing a little, set the idle a little higher, and took about 1.5 qts out of the tranny. It shifts perfect in reverse... now to figure out that idling problem..
 
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