Quad four problem

[chevync]

I noticed saturday when i was going to get my oil changed the car started to buck on me, so I pushed in the clutch, it idled fine, revved it, smooth like always, as soon as I put it back in gear it starts again, then when on for a few minutes then cleared up. Monday morning i was on my way home from work, and it started about 2 mile sin to my 20 mile trip, I stopped at auto zone and picked up some plugs/wires, like to never made it home..Changed out the plugs/wires, after a mile or two it started again, stopped to put some more fuel in it, and it started idling very low, to the point it was about to die and also poured out black smoke, I got it home and started checking vacuum lines, I found one at the Map senser that was bad, replaced it, another test drive, still after about 2 miles it started again...Can anyone help??? Also did a scan it said the idle control sensor was bad, but i dont see this affecting the "loading up" im getting, also when i took the old plugs out they were black, and reaked of gas....

[nicky gio88gt]

Is your ses light comming on at all? Your car is definetly running rich and an AIC sensor could do that, but then again alot of sensors in your car can do that.

[chevync]

yes its on, i scanned it and it came back idle control, but i dont think that could cause the problem, also checking into the fuel pressure regulator, any idea were that would be?

[rweatherford]

Fuel pressure regulator is on the end of the fuel rail.  Look for fuel coming out of the vacuum hose.

Which spark plugs were black?  Suspect either a bad coil cover or bad injectors.  Swap injectors around and see if the black plugs follow the injectors.  If not then it is likely the coil cover or a bad coil.  It could also be a bad ignition module.

[Mr Goodwrench]

QUOTErweatherford
Fuel pressure regulator is on the end of the fuel rail.  Look for fuel coming out of the vacuum hose.

Which spark plugs were black?  Suspect either a bad coil cover or bad injectors.  Swap injectors around and see if the black plugs follow the injectors.  If not then it is likely the coil cover or a bad coil.  It could also be a bad ignition module.

Check this stuff out..
Try to clean the tb out an the iac valve.  
think abought some new good plugs

Mr Goodwrench

[chevync]

All 4 plugs were black, and smelled of gas, the coil cover does have a small hairline crack in it, about a inch or so, what is a IAC valve? Also I put a set of AC Delco RapidFires in it, and replaced the boots as well..IS the fpr on the left side, at teh end, litle bigger than a silver dollar with a vac line running out the top of it?

[Mr Goodwrench]

YUP

Mr Goodwrench

were the coil towers black from carbon build up??

[chevync]

also no fuel coming out of the hose on top of the fpr ...

[chevync]

(Mr Goodwrench @ Jan. 13 2007,01:43)QUOTEYUP

Mr Goodwrench

were the coil towers black from carbon build up??
no, just the plugs

[chevync]

map sensor was toast, had it replaced today, runs great now, thanks for the help!

johnz

[1988GTU]

Didn't you once already replace the MAP sensor?

[Jeff P]

Heh, I misread that too.  He replaced the vacuum line to the MAP sensor.