HELP!!High RPMS after using cruise control, stuck???

[buzz88]

OK - so I was cruising on the highway today for the first time since getting new tires and my B2 was riding so nice I figured I'd throw on the cruise control around 70. Only problem was when I got off the exit my rpm at idle were at 2300, basically felt like the truck was still in cruise or maybe 2nd 3rd gear. when I throw it into park or neutral the engine fires up to over 4000 rpms. Is this a tranny prblem, ignition, or cruise control issue. Stock 2.9, while I'm driving the rpm stay around 2000 to 2500 and with my foot off the gas she just keeps going....Any help suggestions much appreciated...

 

[adsm08]

Sounds like a vac leak. There is no possible way this is a tranny or ignition system issue.

It could be related to the cruise system. Start by pulling off your intake tubing, see where the throttle plate is sitting, it should be fully closed, or only slightly open. If its open more than a few mm, pull the CC cable off and see if it closes.

If its closed, look for a vac leak. Thats a vacuum controlled CC system, so it might have ruptured the diaphragm. If it did, then the CC won't work anymore, if it works, that diaphragm is still good.

The CC system may also have failed to disengaged, if that was the case if should return to normal after a key cycle, but I'd think that putting it in park should have disengaged it.

If none of those have any effect, check for broken vac lines. To hold it around 4000 RPM in neutral its gonna be a big one. You can pretty much ignore the little plastic lines, you are looking for the big boys like the one to the brake booster.

 

[buzz88]

adsm08 - thanks for the input, I think you are right prob a big vac line, because its still happening after turning off the truck, and I believe the cc was still working. If the cc is shot I dont care anyway, rarely get on the highway but nice option to have when it's not blowing vac lines. When let you knoe when I diagnose it...thanks