Chronumn

iTrader: (2)

Having issues starting my FD. It's a 94 with 75k miles. I listed any mods I feel would be relevant below. A month or two ago I hardwired the fuel pump to combat a fuel cut issues. Which is a whole other story that has gone unresolved.

My issue today is my car was running fine on Monday. Then Friday when I went to start the car up it was idling very rough and billowing white smoke from the exhaust until it warmed up and calmed down. My first thought was the car may be down on spark, I pulled the spark plugs and they were all black, I will attach a picture below. So I put my old plugs that still had life back in and started the car back up. Still with the rough idle.

Time to check the compression, when I pull the plugs they are black! Literally letting the car warm up caked the plugs. So I proceeded to check compression and it's good across both rotors.

My next idea is to try new coilpacks, so I picked some used ones up from a friend. My leading 2 had a little corrosion so I think this may be my issue. Install them and the car starts and runs the same. Now, the next day I try and fire the car and it doesn't start at all. Switched coilpacks last night and get the same results. Now I'm here asking for help.

Also if it means anything the exhaust temp light came on last time I tried to start the car which I know has something to do with the PFC.
Thanks for the help.

update: Hooked up my new fuel pressure gauge and it's read just over 40psi when the engine is cranking


Mods
Mazda Reman w/ low miles
Garret T04 Single .70AR
HKS 50mm Wastegate
Apex'i Power FC
Aeromotive Stealth Fuel pump, FFE Fuel Rails ID 2000 secondary & 725 primary injectors w/ hardwired fuel pump
Pettit Racing Air Pump delete

MjhRotor

iTrader: (1)

Billowing white smoke and rough running that goes away after a bit sounds like a bad coolant seal.

MjhRotor

iTrader: (1)

A good way to check for this is to let the car sit a while maybe a day pull the spark plugs and turn it over if you get coolant from the spark plug holes you know you have coolant entering the chambers slowly while the vehicles sitting.

Chronumn

iTrader: (2)

Would this keep the car from starting though?

MjhRotor

iTrader: (1)

It certainly would have issues starting with a rotor full of coolant yes.

Of course you need to do some diag to be sure as this is only a potential cause.

Chronumn

iTrader: (2)

Gave Cam @ Pettit Racing a call and he came to the conclusion it may be a stuck injector so I might bring the car up to him to check it out.

MjhRotor

iTrader: (1)

That certainly would be a more desirable problem to have than a coolant seal. Though, to much fuel should produce black smoke.

Good luck and report back with results hopefully it's something silly.

Chronumn

iTrader: (2)

I'll keep updating this thread so some else with this problem can go have a nice list of things to go through.

Cam did mention coolant seal but.. he said that the car would idle rough with a lot of white smoke and then clear up. Which it doesn't or didn't when it started. Now it's just plain not starting as mentioned above. He also told me to check the cap? on the motor to see if coolant is right at the top. I'm going to find out what this cap he is talking about is and check it out soon.

MjhRotor

iTrader: (1)

Your original post described exactly that hence me originally thinking coolant seal.

Chronumn

iTrader: (2)

Ah yes misunderstanding on my last post, I meant idle clearing up. Not the smoke.