1995 Ram 1500. Just rebuilt the 5.2l and finally started it up for the first time a day ago. It runs good and doesnt have any clunking noise or any serious internal issues (SO FAR). I am having a couple problems though and I'm not quite sure what to do.

1.I have tried to set the ignition timing. This is my first time so I'm not a hundred percent. Because I have the higher lift cam a mechanic told me to make retard it to 5 before TDC. I have it in that area, but it is not consistant. The line (on harmonic balance or the dampener?) hits the same spot a few times but then skips around a bit in both direction (almost 5 notches in either direction). Is this a timing chain issue?

2. When the truck is running it seems to idle fine (just below 1000rpm). If I gradually go up to 2500rpm and gradually back off of the throttle it is also fine and hangs just under 1000rpm. However when I give a sudden spike and let off completely the rpms dip to only 250 but bounce back up to 750. When I took it for a little drive it would stall when I let off the throttle (more than 3 times). Is this an ignition timing problem? and if so what should i do to fix it.

Also I get a wiff of gasoline (maybe its running too thick?) when the truck is off and the exhaust has white smoke (I think its only condensation... doesn't have an oil or fuel smell or a tint to it). Thanks for the help guys.

 

Ignition timing is not adjustable. Turning the distributor only changes Injector timing. (fuel sync) Need a scan tool to properly set fuel sync. Timing is completely controlled by the PCM, and gets its reference from the crank sensor. Turning the distributor does nothing for spark.

Did you replace the timing chain and gears when you did the rebuild?

Think I would pull the throttle body off, (battery disconnected) remove the IAC from the back, and clean the pintle/IAC well REALLY good. Put it all back together, hook up battery, turn ignition "on", but don't start yet, count to 10, then start the engine. Let it warm up some, and see if it can control idle any better. If not, replace the IAC.

 

Did you replace the crank position sensor when you did the rebuild?
If it is high mileage (~100k), it is likely not as accurate as it once was (senses a wider arc)... if the CPS is triggering the PCM early (or late), your timing will be off by that number of degrees, and that will have a trickle down effect to everything else (that is going by the assumption that the timing is correct, when it is not).

 

OP...You need a new mechanic.

 

When I did the rebuild I got new timing gear/chain. The mechanic has been volunteering his time coming over to my house and helping me, but we are getting to the point were we are running out of possible problems. He has turned the distributor cap, and moved all the plugs one space clockwise which seemed to make it idle better. It also would not stall when driving.... BUT it does not have the power it should still. He suggested I tear down the front and check the timing chain to see if it was a tooth off, it wasnt. I'm putting all that back together now and he suggested I disconnect the exhaust after the headers to see if its possibly a clogged catalytic convertor. The IAC is only like $35 so I will either clean or change that also and maybe replace the positioning sensor? Other than this he agrees that it may be a computer issue. Anyone have any other ideas? I would hate to go out and get the new programing and have it still run poor.

 

Turning the distributor does NOT change ignition timing, it changes INJECTOR timing. You need a good scan tool to reset fuel sync. (relationship between cam sensor in the distributor, and crank sensor.)

#1 is marked on the distributor cap for a reason. For the engine to run right, that HAS to go to the number 1 plug, and then fuel sync needs set correctly. Need to get that right, before anything else is going to be effective.