hey guys long time no see, i think i told yal i lost my ram to a wildfire last year and picked up a ramcharger, but now its acting up a hair.

ok guys so my 1993 ramcharger with the 360 with fuel injection is acting up. didnt used to do it, but it developed a weird POP when u are under a load and the engine is still somewhat cold, doesnt seem to do it when warm. so example...i start it, and head on down the road, make it downshift into a passing gear and it will slightly stumble and give a couple LOUD Pops, but it still has ***** and gets it. once warm i cant seem to replicate it. I have changed the plugs, wires, cap, rotor. i ran a can of seafoam through it and i think it helped a little. i tried to mess with the timing with the truck runnin and i thought i got it fixed cuz i couldnt get it to do it anymore once i messed with it a little, but its still there once the engine was cold again. I recently put the FI Airgap on so i got rid of the POS Plenum design, and its not related to the airgap install, it did it before it also. So only thing i can think of that might cause it thats left, is maybe the o2 sensor? since it did have the old plenum on it when it started. and im not sure if its the original sensor or not. my step dad thought maybe it wouldnt hurt to check the distrib pickup inside the cap. any ideas guys? i also ran seafoam through the fuel. i dont think its a fuel filter problem because it would do it cold or warm. also i cleaned all the throttle body sensors and such. so those should be good. just seems like a sensor problem to me.. let me know guys thanks.

 

and please dont move this thread to the other sections because i already posted it there and got no help. and my engine is the same as we had in our rams so please give me help and not move this thread

 

Check your fuel pressure when cold and then when warm

 

^^ this and the MAP sensor.

 

Mine used to do that on large throttle opening acceleration. Crank sensor fixed mine.

 

maybe its just me, but the fuel pressure idea doesnt make sense, its still gonna push the same pressure either way hot or cold, yea i know things expand but the line is only one size, dont change. ill check the other sensors, im just tryin to get a list of things to check. its not a super big deal cuz when its warm its awesome, runs perfect, but i like things to work right all the time.

heyyou your talkin about the crank position sensor? how did that cause this problem? just by miss calibration of the sensor?

and yes i forgot to mention it only pops on hard accelerations when cold. WOT. so it leaves me to believe its a sensor for sure, like the o2, or the MAP. but i already cleaned all the sensors on the TB. only one's i have not check is the o2, and the crank. i think ill start with the o2 just cuz of the old plenum that was on it all that time. so it needs to be replaced anyway, if that dont get it then ill try the crank. and im gonna seafoam it again. thanks for the ideas guys. its chasing the little problems that suck, big ones are easy :P

 

I don't know how exactly or if there's a difference between the years of Magnum engines, but did you twist the distributor when you tried to change the timing?

If so, then your fuel sync may now be messed up. The ignition timing on a Magnum engine is completely controlled by the PCM, so twisting the distributor won't change your timing. It will, however, change your fuel sync which will need a specific scanner to correct.

O2 sensors wouldn't hurt to replace, but your truck should be bypassing the O2 sensor when cold anyway. Crankshaft position sensors are pretty notorious on the Magnums. Only buy a MOPAR one.

Crank sensor gives PCM location of crankshaft, which is probably how the PCM sets ignition timing. just something to think about...

 

PCM ignores the O2 sensors at large throttle openings.

Use some variety of spark checker on the coil wire. Crank engine, make sure that spark is strong, and consistent. If you get any variation, replace crank sensor.

Reset fuel sync. Turning the distributor does absolutely nothing for ignition timing, that is all controlled by PCM via the crank sensor. Turning the distributor changes injector timing. (via the camshaft position sensor in the dist. or, pickup coil.)

Test TPS. Should be less than one volt at closed throttle, greater than 3.5 at WOT. Progression should be smooth throughout the range. (analog meter to test please, digital doesn't react fast enough.) If it is out of range at either end, or, bounces around as you open the throttle, replace it.

Check connections at coolant temp sensor. Yours has two, one (single wire) is for the gauge in the dash, other one (two wire) is for the PCM.

 

ok guys thanks for the help and input, i change the 02 sensor, coolant temp sensor, and the crank sensor, and it appears to be fix now, it had a slight stumble but it was different with NO POP like before, so i moved the dist again back closer to where it was before and got rid of the stumble. but it was also warm but that point, so in the morning will be the true test. thanks guys.

 

Did you disconnect battery when you changed sensors to reset PCM?