1990 5.7 TKX swapped

I started it in the garage and noticed an unusual rich smell.
While driving and stopping it would stay at 1500rpm before after some time slowly go down to 750rpm.

I searched and didn't find any info on this issue.

Advice is always appreciated!

 

P/n wire ungrounded ? Vss signal to the ecm ?

 

P/N wire?
VSS is done with the Dakota Digital SGI-100BT

 

D16 on the 730 is p/n for automatic. Should be open circuit on a manual transmission. What tune did you use or did you mess with throttle follower ?

 

Please excuse my ignorance.
I researched the TKX swap for a year before I decided to do the swap and didn't see any changes needed for the ECM other than the VSS which is the reason I got the Dakota box.

How should I unground the p/n wire?

The tune is the same from the auto.
I had the engine modified by Ray Bohacz when he had Precise Automotive in NJ back in the mid 90's. He did the custom chip.

I did not mess with the throttle follower. I don't know what that is!

Thanks for the help

 

https://www.thirdgen.org/forums/diy-...llower-8d.html

you can unpin the orange white wire d16 at the ecm or tape it up at the old gear selector. It may only decrease idle 50-100 if it’s grounded now.

 

That's a good detail to catch. It's not uncommon for that kind of detail to be overlooked in swaps.

 

IIRC That wire on the shifter only grounded when the shifter was in park.
Once the shifter connector is unplugged it would be open

 

At this point I don’t think this issue is do to the TKX swap.
It ran well without this problem for about 20 miles.
Going to try a IAC reset

Thanks

 

Crazy hot here and have my daughters graduation party this weekend so won’t be able to troubleshoot till next week

 

I reset the IAC and did a vacuum leak test. I sprayed starting fluid around intake and didn't notice any idle change.

Took it for a 25 mile ride and it seems that issue has been resolved.

 

I may be out of my league here, but I would think about engine timing.
Is your timing controlled electronically? If it is set without separating the electronic spark timing (EST) from the circuit, it will try to correct any adjustment you are making to the timing and thus throw it completely out of whack.
Would be an explanation for why it ran properly for a while, as your temperature and engine load values relevant to timing keep changing. EST can only adjust so far.
Or has the distributor locking clamp perhaps loosened up and timing has changed because of it?

 

I timed it with the EST wire disconnected.
I'll check the timing just to be sure.

Thanks