Well long story picked up a clean 2000 Ram 5.2L w/ a blown motor. Threw a junkyard motor in w/ 70K and good compression. Changed the oil pan gasket and checked out the bearings... changed valve cover gaskets head was clean. New cap, rotor, wires, spark plugs, fresh gas, front and rear seals and the motor will not run.

It fires up but dies immediately. If you keep your foot on the gas or idle up high it will run fine. Cleaned the TB and all sensors, still will not idle. If you unplug the IACV it will idle at 900 with no fluctuation. Picked up a new IACV took it for a ride and it still will not idle.

There are no cels, no oil pooling in the bottom of the TB, no pending codes, no hissing, good vacuum...

Motor is making a pinging noise under light acceleration and even when in park. Thats about it.

What are your thoughts????

 

Throttle positioning sensor.

 

would that cause pinging?

any way to test it? even though testing a sensor is hit or miss.

 

Check the diy section for the prescribed method of testing it. The tps wouldn't cause pinging though. Pinging is either bad fuel, carboned up valves, plenum gasket leak, etc.. There are many reasons for pinging. Do a search and you will be surprised.

 

anybody have a link for the method of testing the tps? i have searched and searched w/ no luck.

as far as the pinging goes as soon as I can get this thing idling I'll further diagnose it. pending the 2 are not related.

 

Get a haynes manual, it tells you how to check the TPS, and the rest of the sensors, besides, you'll want the manual for when you replace your bad plenum gasket.

 

thanks got it... i'll check the tps tomorrow and post my results.

as far as the plenum gasket goes I hope its as easy a fix as that. how much oil is normal. I mean it is not even pooling... just light oil at the edges comparable to condensation.

 

Did you remove the TB , and look all around inside with a mirror and a flashlite?

 

Yes and there is no pooling at all.. there is slight oil residue almost like condensation thats about it.

I have the intake manifold off the old motor and that plenum gasket was clearly blown. oil pooling in the corners and the bottom of the im was a mess.

I can get some pics tomorrow but I'm 99% that is not my prob. I also just tried a TPS off the old motor and it still won't idle.

WTF. Gonna test both TPS's tomorrow just to be sure but IDK what is up.

 

Back to the not idling problem, that is usually the symptoms of a bad IAC.