Phone Man

Hi all,

New to this forum and looking forward to hearing from some knowledgeable members.

I have an issue with idleing in gear but not in park and neutral. Here is some history:

Installed new GM Crate Motor HT383e. Everything was fine until I started having wicked ideling issues a few weeks after. When the engine is cold it runs normal After it warms up in park it's ok. When warm and in gear, the idle will level off as normal then start to slowly go up and down untill it becomes erratic, surges and finally stalls. If I put it into park ar even power brake, it will go away. This process will start over again.


Here is a list of things I have done:

No codes. SES light is off. Replaced:
TPS
MAF
MAP
EGR
IAC
VSS
THROTTLE BODY
COIL
TEMP SENSORD (BOTH)
AIR TEMP SENSOR
OIL PRESS
CAM POS SENSOR
COMPUTER W/STOCK PROGRAMMING
NEW LOWER INTAKE, NEW ARP BOLTS AND FELPRO
CRANK RE-LEARN
TRANSMISSION W/NEW TC
BATTERY IS GOOD AND ALT OK
TIMING SET TO 0

According to the GM TECH II, the engind is running fine. O2 sensors good. I had a plenum spacer that I removed and put back on bc there was no difference.

It did this with the old transmission as well as a new one that I have in now.

Any Ideas????

Thanks

73shark

Welcome to the forum.

Have you checked fuel pressure?

Phone Man

Yup fuel pressure is good. No problems on the highway or acceleration. 54lbs

in2pro

how does the exhaust smell is it running too rich maybe?

Phone Man

I have a scanner and a laptop program. Engine runs exactly 14.7:1

Phone Man

Just replaced the upper manifold and Crankshaft Position Sensor. Still the same. Any suggestions?