idles perfect then jolts and cuts out when put into Reverse or Drive.

[shanesstangs]

Some background: i pulled the drivetrain out of a 1989 Mustang GT 5.0 HO with the AOD transmission. installed it all in a 1969 mustang. ive had plenty of issues but my current one i cant figure out.

Issue: Car idles fine usually, but now im at the driving stage of my project. When i shift the AOD into Reverse or Drive the vehicle jolts and then will die. the RPMs drop real low. usually if i push on the gas a little when i shift i can get it to stumble into gear. now this is a new transmission that i serviced and set TV pressure to 35psi with the spacer. not really sure where to go next with this thing. any help appreciated!

 

[General karthief]

EFI or carb?

 

[shanesstangs]

EFI or carb?

EFI

 

[86HO5.0]

Codes?

 

[General karthief]

Operating temperature idle rpm?
You need to make sure all the harness grounds are connected similar to the stock locations, the important ones for the computer are, battery to computer ground, ground for the injector harness, there are other stuff that need addressing so I will refer you to the tech thread here:

Help me create the "Surging Idle Checklist"

Updated 05 July 2022 to add rough idle when cold and smooth idle when up to normal operating temperature. See the EGR tech information, section #15 for more help. Many of you are familiar with the "Cranks OK, but No Start Checklist for Fuel Injected Mustangs" checklist and the No Crank...

www.stangnet.com

This will show you how to check and adjust stuff and covers checking codes too I believe,
I'll leave this here for a minute to get some responses going then I'll move it to the appropriate forum.