I'm having starting issues with my car. It will start, then ifle really rough, then shut off. This repeats several times with no change in status. I've done everything I can think of, replaced PCM, new spark plugs, new injectors, new MAP, new Crankshaft Position Sensor, checked wiring at PCM.... Fuel pressure to the rail is right at about 58psi. Something else I noticed was that it isn't firing on all cylinders. 1 & 3 are cold to the touch and 5 & 7 are hot. Ive checked wiring on the injector harness as well. Any clues? Thanks.

 

Did you change the plug wires as well or try moving the wires or coil packs around with cylinders that are firing?

 

I did not, but I will give it a try to see if the issue moves. Thanks.

 

There's a diagnostic/tune forum for issues like this...
Read the stickies.

 

Moved to PCM section. Might get more traction over here

 

What DTC's are you getting?

 

I'm not getting anything at the moment. I was getting one for the MAP, but I replaced it.

 

I think I forgot to mention, but it smokes like nobody's business! A very white smoke at that. I'm at a loss guys. It ran (rough) when I bought it, I drove it home, and haven't really been able to drive it sense. I did find out that the guy I bought it from was driving on a "start" tune. It was wired for Nitrous, but It looked like my 6 yo wired it, so I removed it all. I've been working with Casey from Texas Speed, but he can't really help me if I can't get the car to run long enough to get a read. I've replaced the PCM and loaded the previous tune sent by Casey (based on mods completed) and it still does the same thing. A friend told me to remove the valve covers and check the rockers and springs and as far as I could tell, everything was kosher. All of them were tight and nothing was loose. I'll keep you all updated. I'm going to check the coils soon. Thanks!

 

White smoke can indicate a head gasket failure. Does the while smoke have a sweet smell to it? Are you finding you are constantly low on coolant? Or is your oil kind of chocolate milkshake looking?

 

To be honest, I haven't been able to drive it to see if the fluids are nasty or low. Oil looks fine now. It does not have a sweet smell, but the smell is a strong exhaust smell. If that makes sense.

 

White smoke can also be condensation in the exhaust.

Do you have a way to data log it?

If there are several cylinders cold to the touch, which obviously means they aren't firing, I would expect a P0300 or several P03xx DTC's unless they have been turned off in the tune.

 

I've been using a buddy to log tunes. I do have a check engine light now, so I'll have him flash it for codes. Thanks.

 

So I swapped cylinder 1 and 5 coil packs with no change in state. 1 still is not firing. I also noted that 2 and 3 aren't as well. The rest are firing. I also swapped plug wires with no change. I'm actually really baffled by my issue. I've done just about everything I can think of and what has been suggested. Any ideas?

 

My suggestion is to first figure out if you're getting spark on those two cylinders, if not, try swapping the coil packs bank to bank and see if the missing follows to the rh bank

Sounds like the coils are probably good, but moving individual coils doesn't eliminate the coil pack harness, they can get kinda crusty

 

Which PCM are you using? What are you using to scan PCM for DTCs? What does oil pressure show when it starts? Have you verified injector and coil firing signals on problem cylinders (compare to good)?