I gots a 86 sitting, and it is running really rough, about 7-10 mpg city, 14 max hiway. Thinking o2's, but I dont wanna spring for em till I know what the problem is.
I know its getting pleanty of gas, as a matter of fact, it leaves a black stain on the ground anywhere it is parked running. Jet black exhaust, and it isnt getting any better. I know the timing is off on it, but that isnt the whole problem. It did this before it sat for the last year, and before I pulled distributor out to test the one out of my crown vic in it.
But yeah, really really rich, jet black exaust and bad(horrable) mpg. It acts like my dads motor cycle does when you have the choke on after its all warmed up.
Step 1: Fix the problems that you know about.
Codes!
Leaky injectors maybe?
I will pull codes and re time it, then I will let you know. Honestly I am thinking a stuck egr valve.
EGR valve wont cause it to run rich. Sounds like a fuel pressure regulator.
FPR has already been changed.
Doesnt mean its not defective. Check it again.
Pull your spark plugs. See if they are all running pig rich, or just a few.
I changed them out about a week ago, prolly 20,000 miles on them and they were black too. all 8 of them. I will pull a new one too.
Mine does the same thing, and leaves a huge black stain. Mine was looked over at a dealer before I bought it? HMMM??
Most likely your O2's...don't be a cheap ass, replace them. You will end up needing to either clean or replace your EGR now, I'm sure...it will be all full of carbon from running so rich.
Ok, someone educate me, Where the hell is the EGR at?