5.7 tbi surging and stalling

[Wanderer 290]

Hi, I am working on a little problem and any input is appreciated.
01 290SD with twin 5.7 TB efi. B3 with 400 hrs and fresh water.
After a few minutes and at 170* the port engine begins surging and dies. Any thing above idle and NO problems. I bought a new IAC from Autozone and put it on the SB engine and moved to SB IAC to port and still have the problem. If I disconnect the coolant temp sensor the surging is less frequent and the engine does not stall.

My next step is to swap coolant temp sensors and if no joy swap the ecm’s.

Thoughts

Thanks

 

[Strecker25]

Hi, I am working on a little problem and any input is appreciated.
01 290SD with twin 5.7 TB efi. B3 with 400 hrs and fresh water.
After a few minutes and at 170* the port engine begins surging and dies. Any thing above idle and NO problems. I bought a new IAC from Autozone and put it on the SB engine and moved to SB IAC to port and still have the problem. If I disconnect the coolant temp sensor the surging is less frequent and the engine does not stall.

My next step is to swap coolant temp sensors and if no joy swap the ecm’s.

Thoughts

Thanks

I had a similar thing on our 98’s. The ignition sensor under the distributor would get hot and do crazy stuff, cut out, etc. you can replace the module but it’s a PiA so I got a new distributor. Problem solved.