1995 GMC Yukon stalling out

[Smith1]

Need Help..I own a 1995 GMC Yukon GT. It has a new jegs crate motor plain Jane and a rebuilt transmission 4L60E. I can drive my truck and every now and then when I slow down close to stopping the truck will cut off. I can usually start it back up go on about my way. The map sensor I am using came off the old engine could that be the issue? Any ideas would be appreciated. I could also answer any questions if I didn't provide many details.

 

[Tonyrodz]

Are you getting any codes?

 

[drakon543]

is the map sensor the only thing that was reused? any other electronics, intake manifold, and i could be wrong as i always mess up the year but i believe yours is tbi. was the tbi unit replaced entirely or rebuilt before it was swapped.
early in the morning so ignore my poor grammar pls.

 

[Smith1]

Are you getting any codes?

No codes being shown..this vehicle was messed with alot before I got it wiring wise anyway..it doesn't seem like it is a fuel problem cause it idles well runs well doesn't sound like it's choking just when I deaccelerate it shuts off.

 

[drakon543]

intake leak, tbi could need a refresh if it wasn't done. tps sensor could be faulty. also i could see the map possibly causing some issues but i think it would be more wide spread.

 

[Smith1]

intake leak, tbi could need a refresh if it wasn't done. tps sensor could be faulty. also i could see the map possibly causing some issues but i think it would be more wide spread.

I didn't rebuld the tbi. I just did a swap with the intake over to the new engine but checked of course for faulty issues. Is the TPS Sensor a relatively easy fix?

 

[Tonyrodz]

I'd think it could also be the iac.

 

[Smith1]

I'd think it could also be the iac.

The idle air control plug is the 4 pin plug that goes into the side of the throttle body correct?mine has the little latch pin broke on the side so maybe it's not making a good connection.

 

[drakon543]

it could be that also but i didnt suggest it as you said its only stalling when you slowing down to a stop. if its generally having trouble holding an idle id be more suspicious of the iac

 

[drakon543]

if you have an intake leak it could be pulling air through the leak when your throttle plates close. its possible but you would usually see other issues tied with that. i only suggested that as it was probably one of the parts you swapped as usual with crate engines. if the tbi is leaking fuel around the bowls it could be happening when you let off the throttle. couple things you can try is remove the air cleaner pan and bump the throttle a few times watching in injector spray. if it doesn't hold the cone spray pattern or you see some fuel leakage it could have some issues. as for the broken clip for the iacv the wire connector is fairly cheap at advanced auto id replace it just for the fact it is broken. as for the intake recheck the bolts and make sure none of the bolts loosened up.