Rough Idle after thermostat replacement

[jcabe1794]

New here and new to expy's all together. I picked up a 2000 EB Expy and so far have loved the truck outside of a few maintenance issues it has been flawless. I noticed I had a stuck open thermostat and replaced it two nights ago. Now I am experiencing a terribly rough idle. Rpms are jumping from 500-700 and it almost seems like it wants to stall. So what did I do it ran fine before the thermostat replacement. Did i foul the MAF sensor, possibly get coolant on a coil causing it to misfire? Please help I had an otherwise great running truck that now idles terrible.

 

[Bedrck47]

recheck the coil connectors use some dielectric grease on the contact points

with the engine running you could disconnect the coil connectors one at a time to see if the idle changes. if a coil or the boot got water in it you shouldn't notice any change in idle speed but if the coil/boot/plug is ok then the rpm's should drop

If you find a misfiring cyl. Remove the coil and boot Blow out any water that may be in the spark plug well. You may also want to replace the boot and use dielectric grease on the boot wire.

Are you getting a CEL if so get the codes read

How many miles on the expy and when was the last time plugs/boots/coils were changed

 

[jcabe1794]

Computer is not throwing any codes. I just purchased the truck about 3 months ago with 160k miles on it. I dont really know the service history, but it was a one owner and is in exception condition.

 

[Bedrck47]

check what I posted above You may also try to contact the previous owner and ask about the plugs/coils or change them out.