96 dodge ram 5.2 magnum
Cold start shakes whole cab for about 45 seconds to a minute and half after that it runs perfect and fires up throughout the day no problems at all until the next morning.
replaced plenum gasket, TPS, MAP, IAC, Ignition coil, engine coolant temperature sensor, crank and cam position sensor, fuel pump assembly, cleaned gas tank out,
cap rotor wires, compression 125-135 across the board without WOT (forgot to hit the gas pedal while doing it) ,cant find any vacuum leaks (spraying air intake cleaner where i think there would be one) , upstream o2 sensor i have no catalytic converter
Ive put a 15" hollow metal rod about 1/4" diameter on all the injectors to feel if they are pulsing and they seem to be pulsing fine.
Truck only has 158,000 KM on it
i know the valve stem seals might be bad because it burns a bit of oil and cylinder 8 plug gets a bit fouled every 4,000 km (oil/carbon build up on plug but doesnt smell like gas)
Im running autolite 3923's
im at a complete loss ive read everything i can on most of the forums and have run out of ideas. thanks for your time and any suggestions.

 

Use a temp gun on the exhaust manifold to figure out which cylinder is misfiring. Then swap injectors to see if the miss moves.

 

It will be hotter or colder?

 

The misfiring cylinder will be colder. It may take several tries as the whole manifold warms quickly and the temps even out.

 

I have headers so I think it might be easy to find that way

 

My 5.2 hated 3923s. Could be bad plug?

 

I figured since I posted I might as well update it’s been raining here but before I started the truck up this morning I put my msd coil back in instead of the one from part source then I reset the pcm before I fired it back up. it popped twice shook for maybe 5 seconds and was better than it’s been in a long time so I’m not sure what’s going on with this thing but I will be trying the temp gun on the headers and swapping injectors around to see if it is an injector problem

 

Stock coils are best. I remember years back people complained of MSD anything.

 

So I replaced the injectors everything was fine no more cab shake in the mornings on cold start. New problem now it cranks forever when I start it takes 10-15 seconds of cranking to get it to start, this morning I had to keep pressing the gas pedal to keep it alive it kept dying out on me
Long term and short term fuel trims are around -28 to -33% now

 

Did you install stock injectors, or bigger ones? Or even different ones.... Unfortunately, not all companies use the same method to flow rate their injectors.

Looks like you are running rich..... Is one of 'em stuck open??