Idle with dips... Why???

[Ton van der Sluijs]

Hi everybody
As long as I own my truck, On LPG, as well on gas, idle is at 750revs, but after a couple of minutes the dips occur... and sometimes the engine stalls.. Everything what has do with "making sparks" in new.. New valves, new Hego and new MAPsensor.. the only thing what's not onboard is the smogpump..
Sometimes I do have the idea ,that during idle the Hego cools down a bit..
does anyone has suggestions?

best regards Ton

 

[primetime]

Have you cleaned/swapped your idle air control or checked your TPS sensor Ton?

 

[Ton van der Sluijs]

Goodmorning Justin;
I've bought a brand new TPS sensor and I've cleaned the IAC valve.. TPS is checked an gives a good voltage an IAC gives a neatly 1100revs when starting cold... What else can I measure on the IAC?
Thank you very much for you input

Ton

 

[smokey]

Sounds like the iac is sticking..

 

[Ton van der Sluijs]

Okay Smokey; thanks for the input; appreciated!! I shall dismantle it this week.
I've read somewhere that indeed the IAC's can give troubles..

Best regards Ton

 

[primetime]

Anytime I`ve had one of these trucks rev up then idle down to the point where they`ll stall it`s been the IAC. I`ve cleaned them, put them back on, fired them up and they are fine. Go out the next day and right back to where they were. I`m not saying it`s your problem, but if you can get another one to try that might not be a bad idea. Have you checked for vacuum leaks?

 

[Ton van der Sluijs]

Goodmorning
I've checked all the vacuumhoses; they're fine.