2000 Dodge RAM 1500 5.9L V8 Magnum...

The timing adjusting itself all over the place during idle isn't normal, right?




Could this be a bad ECM? The only other thing I can think of would be a bad distributor... perhaps the cam position sensor? But, the timing evens out perfectly when RPMs are over 1500 or so. It's only at idle, accelerating through 1st gear, and when under load (going uphill, etc.) that it does this (which seems to be the cause of the engine stumbling through acceleration)...

I just had the engine completely re-manufactured, and so it has a brand new timing chain in it...

Any input would be greatly appreciated!

 

Could be the plenum, oil covered spark plugs will mess with everything

 

Does it do it cold? If in open loop rule out o2 sensors.. look at IAT and temperature sensors.. what does it read as temps when its doing it?

 

Shouldn't be the plenum. The motor has about 500 miles on it. New gaskets, heads, pistons, lower block, lifters, etc., the works.

Cold, hot.. doesn't matter. It isn't the O2 sensors. I replaced both of them just to be sure.

It does have a Compcam camshaft in it, but it is the least-aggressive one they make. Nearly the same as factory. It shouldn't be causing this sort of thing.

 

It's jumping, its not that its steady.. rule out the cam..

The o2's are out if it does it in open loop..

Check your IAT.. unplug it, and see if it jumps like that.. do the same (not at same time) with coolant sensor.. engine should run off tables at that point.. see if it continues.. if it does, there are two other things to look at..

 

timing jumping wacky-assed crazy at idle is normal.

Now in-gear with a load on the engine jumping like that is not.

 

Still jumps and has engine sinusoidal hesitation under load or acceleration through 1st with the IAT unplugged.

With the coolant sensor unplugged, the engine didn't want to start for some time, and there was quite the ozone/sulfur smell coming through the vents when the engine did start. Timing still jumped around, but I didn't want to drive the truck much with things behaving as they were. Wasn't able to test uphill hesitation.

 

Coolant temp sensor is critical during open loop operation. Not surprised you had a hard time starting it.

 

Wonder if that is a product of torque management, trying to go easy on the trans?