Idle Flux:

[wag928s]

Porsche, 85 US Edition, 5 speed, 32 v. Idle at start up is from 500 / 2500 rpm's, when it is warmed up, stays steady at 1200 rpm's. I replaced the temp sensor, had the MAS unit rebuilt and put in another known working idle stabilizer unit. I have checked for vac leaks throughout all seems to be OK.

Anyone have any suggestions? I have been though the manuals on this one. I have also replaced most of the relays too but this problem continues on.

Any help would be appreciated!!!

[Danglerb]

1200 rpm warm idle is way too high isn't it?

Air is getting in somehow, start checking all the ways.

Surging only when cold makes me guess its something related to a temp sensor. I would start by verifying the sensor signals at the brain.

[wag928s]

Danglerb:

Whether or not is it suitable, I filled a spray bottle of water and started to spray it on the vacuum connections and found several hoses that were swollen up, not making a good seal. After replacing them, now it idles nice.

One was under the MAS on the 5 vacuum hose plastic unit, (I replace the whole thing with a much more rigid unit) and another from the throttle unit where the hose was actually split.

Thank you for your help!!!

[rhjames]

Originally Posted by wag928s

the vacuum connections and found several hoses that were swollen up, not making a good seal. After replacing them, now it idles nice.

If several were bad, you can bet the others won't be far behind......suggest you replace all vacuum lines at this juncture.

--Russ