87 LX 5.0 issue

01silverstang

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So my father-in-law and I picked up an 87 LX 5.0 that was T-5 swapped recently. When. He first went to look at it, it ran fine. When we went to pick it un it would not start. We put it on a dolly and brought it home with the plan that we are swapping the T-5 into his 89' GT vert and his AOD into what will be my 87'.

Today we adjusted the timing slightly without a timing light and we got it to idle well. The alternator is good, the battery is good, it's obviously getting fuel to idle.... However, as soon as we slip it into gear and try to drive it stalls. We are at a loss as to what is going I or what to check next? We plan on getting a timing light, to dial it into to stock timing perfectly. It just seems baffling that it runs in neutral but not in gear???

Any ideas or help would be appreciated!!

Edit: Does this sound like an IAC issue?
 
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wesessiah

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did you leave the manual computer in with the aod? did you swap in the auto computer to your car without modifying the harness? both can cause issues, with the second possibly causing damage. t5 to aod isn't as direct as aod to t5.
 

01silverstang

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did you leave the manual computer in with the aod? did you swap in the auto computer to your car without modifying the harness? both can cause issues, with the second possibly causing damage. t5 to aod isn't as direct as aod to t5.

We haven't done anything to it, the previous owner did the swap. It apparently ran fine last summer, but has sat in a garage all winter.

It was my understanding that the only thing different between an AOD 5.0 and Manual 5.0 was the transmission harness between the transmission and ecu?
 
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FISHTAIL

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ECU's are also different. That said, which of the 3 cars is having the issue, and what has changed? It's not abundantly clear from your original post...but do keep the ECU swap in mind when you start this whole thing. There are several different ECU's, and they are not all interchangeable.
 

01silverstang

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ECU's are also different. That said, which of the 3 cars is having the issue, and what has changed? It's not abundantly clear from your original post...but do keep the ECU swap in mind when you start this whole thing. There are several different ECU's, and they are not all interchangeable.

Well I doubt the ecu is the issue as this car ran last summer for the previous owner after the swap. I have looked through a lot of transmission swap guides for the 5.0 and I have yet to come across one that lists ecu as needing changed?

I'm starting to think its a vacuum leak... Last Saturday it was sunny and 50's and we finally got it to idle for about 10 minutes, sounded like it had a healthy cam but it's stock cam. Then when we attempted to drive it, it died and wouldn't idle again.
 

wesessiah

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figure out what ecu/harness setup is in it, nobody can say definitively without knowing exactly what combo you have, but you haven't seen all the threads on various sites about aod with an a9l if you think this issue never comes up.
http://forums.corral.net/forums/general-mustang-tech/1094179-oxygen-sensor-harnesses-manual-auto-differences-year-differences.html
http://www.allfordmustangs.com/forums/5-0l-tech/119449-1989-mustang-t5-aod-swap.html
http://www.allfordmustangs.com/forums/5-0l-tech/68088-a9l-computer-aod.html
 

01silverstang

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figure out what ecu/harness setup is in it, nobody can say definitively without knowing exactly what combo you have, but you haven't seen all the threads on various sites about aod with an a9l if you think this issue never comes up.
http://forums.corral.net/forums/general-mustang-tech/1094179-oxygen-sensor-harnesses-manual-auto-differences-year-differences.html
http://www.allfordmustangs.com/forums/5-0l-tech/119449-1989-mustang-t5-aod-swap.html
http://www.allfordmustangs.com/forums/5-0l-tech/68088-a9l-computer-aod.html

I'll check tomorrow and report back.
 

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