O.K. i have a 98 b1500 van sometimes called the ram van
it has several issues but the main one which is not related to the others is this one it will not start.
weather damp and rainy , yesterday it took about 3 tries to get it started then it ran fine for the day , today it cranks but will not start, i shot some starter fluid in it and that causes it to back fire, it backfires wiithout it too but it is a muffled one. it has spark at the cap and the wires i replaced the cap first as it was crudded up real bad and i thought that was it, nope, i checked all the fuses and found the fuel relay fuse blown so i replaced it it did not blow again, still nothing my neighbor has a code checker and it pulled three codes they are: p0320,p0545, p0545.
on side note i have a haynes manual which only covers 2 of the codes, here is description of what the codes are: p0320 is no crank reference signal at pcm i put a multimeter on the sensor and it checks good also checked a new one out same readings.,p0545 bank 1 sensor 1, circuit low for exhaust gas temp sensor, p0505 idle air control motor circuits.
the crank sensor goes straight to the pcm no interruptions wires appear good no breaks or burns, the exhaust temp sensor i am not sure where it is and the idle motor i haven't checked, is my pcm shot? would all 3 problems cause it not to start i dont want to replace the crank sensor since it is reading properly so i am at a loss here any help would be appreciated.

 

well i have to add a reply, now that it is warmer out and all the moisture under the hood is gone, i was able to start the van and go to the store, i got back borrowed the neighbors code checker and there are no codes on it, i guess what happened was where i was parked caused a lot of moisture to build up under the hood because it was severely wet and caused bad signals or the pcm not to work properly but now it appears fine.
so is there any product out there i can spray on my wires and modules to repeal the water i seem to remember a silicone based product from many years ago.

 

Nope, cant say I've ever heard of WD-40. Congrats! You did a hell of a job of troubleshooting a newer obdII vehicle! Nice to see someone do the work, rather than just throwing parts at it. My 95 Ram did the same thing at 7k when it was new. Cracked cap.

 

I guess sometimes it pays to plug it in, cap and rotor was just coincidental it still prolly needs plugs and wires. cool nice to know i can use wd-40 on the electrical to help keep moisture out , whats really wacky is that when i unplugged the pcm and plugged it back in my trip odometer no longer automatically resets when i turn the truck off!

 

The problem with WD-40 is that it is water deluted.

On electrical conections, use di-electric grease. It is designed just for this.

 

ive got a 2001 ram and im in the process of stripping it down to bare bones, and the pcm is currently disconnected with a superchips tune in it for a 5.2L dodge,