My daughter's 1986 GT has always had black soot around the exhaust pipes for the past 2 years she's had it. A couple of weeks ago, the car was occasionally hard to start. Then one day she couldn't get it started. When I tried, I noticed fuel dripping from the center of the car and near the driver's door. Turns out the drip near the door was from fuel running from the upper plenum, through the throttle body, and into the air cleaner can. I've always suspected the black soot was due to a bad coolant temp sensor making it run rich. What is the most likely source of this current flooding? Fuel Pressure Regulator? Stuck CSI? Leaking Injectors? I've read lots of posts about flooding but none I found were about flooding this extreme. Need help getting her car running as soon as possible.
Sounds like the cold start injector. The Fiero has a 'clear flood condition' mode, you hold the accelerator all the way down while cranking the engine. Release the pedal once the car starts. There are several threads on removing the CSI.
The fuel pressure regulator can fail, but it won't leave fuel sitting on the engine. For that you need a bad connection or some physical damage..Check to see if the Schrader Valve is still working. Don't let her drive it.....big fire hazard.
The fuel pressure regulator can fail, but it won't leave fuel sitting on the engine. For that you need a bad connection or some physical damage..Check to see if the Schrader Valve is still working. Don't let her drive it.....big fire hazard.
She's definitely not driving it until I get it running right. How do I check the Schrader Valve?
There is a little cap on the passenger side of the fuel rail.. Under it is what looks like a bicycle tire valve. It's for checking fuel pressure...and could be leaking.
The fuel pressure regulator can fail, but it won't leave fuel sitting on the engine. For that you need a bad connection or some physical damage..Check to see if the Schrader Valve is still working. Don't let her drive it.....big fire hazard.
When the diaphragm fails it can, and will most definitely, inject fuel into the the vacuum system at whatever pressure the pump can deliver and it will head straight into the plenum. The fuel pressure regulator shares the same vacuum port as the MAP sensor on the passenger side of the intake plenum.
When the diaphragm fails it can, and will most definitely, inject fuel into the the vacuum system at whatever pressure the pump can deliver and it will head straight into the plenum. The fuel pressure regulator shares the same vacuum port as the MAP sensor on the passenger side of the intake plenum.
Do you check it with engine running or not running.
When the diaphragm fails it can, and will most definitely, inject fuel into the the vacuum system at whatever pressure the pump can deliver and it will head straight into the plenum. The fuel pressure regulator shares the same vacuum port as the MAP sensor on the passenger side of the intake plenum.
The fuel pressure regulator is sounding like the most likely culprit to me. I didn't find how to access it in either the factory shop manual or the Haynes manual. I'm guessing I have to remove the upper intake manifold to get to the fuel pressure regulator.
OK, lets' review. You can check the fuel pressure regulator by pulling a vacuum line and checking for gasoline. Any line should do...but one near the MAP is easy. IF the FPR is bad, there will be no leaks on top of the engine. If you have loose fuel dripping onto the ground, something else is wrong. Maybe there is a split vacuum hose near the fuel rail or something like that.
Fuel Pressure Regulator had both diaphragms worn through. Replaced the FPR diaphragm/spring assembly and have no more fuel running out and no smell of fuel. However, the car won't start. I tried cranking it and it did not fire at all. Held the gas pedal down and cranked it for a long time. It eventually started to hit a little then ran enough to disengage the starter. Engine was just barely chugging along with WOT. As soon as I let up on the gas pedal it died. Did that twice. Pulled the three "easy" sparkplugs and they were normal color and dry. Any ideas on what to check now?
Decided it was likely the car was running rich, after Fuel Pressure Regulator rebuild, because of a bad Engine Coolant Temp Sensor. Replaced the sensor. Car started after long cranking with throttle at WOT. Made lots of blue smoke and idled at about 2000 RPM. After 2 or 3 minutes of fast idling, the idle speed started to drop and at 1000 RPM, the engine died and wouldn't restart. Let the engine sit for an hour or so while I had AutoZone recharge the battery. Car started at WOT after LONG Cranking. Lots of blue smoke, fast idle for 2-3 minutes, then died and wouldn't restart. I'm thinking about deleting the Cold Start Injector by flattening the line from the fuel rail to the CSI.
Blue smoke indicates burning oil, whereas black smoke would be a rich condition.
I think the blue smoke came from oil that had collected around the sparkplugs and drained into the cylinders when I took the sparkplugs out. Yeah, I need to replace the rocker cover gaskets.
I think the blue smoke came from oil that had collected around the sparkplugs and drained into the cylinders when I took the sparkplugs out. Yeah, I need to replace the rocker cover gaskets.
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Geez, just how much oil is leaking from your valve covers?
And along with the oil, what other outside crud (lodged around your spark plugs) might've dribbled into your cylinders?
Have not replaced the fuel filter. What effect does a clogged filter have? What should the fuel pressure be?
fuel pressure should be above 30 lbs with the engine idling. A clogged fuel filter will reduce fuel pressure during acceleration or high speed. If it's really bad it reduces fuel pressure all the time. When fuel pressure is low, the engine loses power.
When the diaphragm fails it can, and will most definitely, inject fuel into the the vacuum system at whatever pressure the pump can deliver and it will head straight into the plenum. The fuel pressure regulator shares the same vacuum port as the MAP sensor on the passenger side of the intake plenum.
Carbon, that was the most helpful information! When I read your post it totally made sense of what was going on and gave me a direction. I'm glad I went after the FPR and rebuilt it first. I still have problems but that one HAD to be fixed first!
Geez, just how much oil is leaking from your valve covers?
And along with the oil, what other outside crud (lodged around your spark plugs) might've dribbled into your cylinders?
I know, I know. It's my daughter's car and as long as she could turn the key and go it didn't matter that there were puddles of oil, I guess. Now she's given up on the Fiero and bought a new Camry. Left the Fiero for dear old dad to fix up and sell for her.
Funny thing is that people often mistake her car for mine and vice versa. Hers is a yellow '86 GT that somebody put '88 notchback body on. Mine is a yellow '88 Formula. Two yellow Fiero notchbacks in the driveway always make people do doubletakes.
[This message has been edited by Timpilot (edited 12-09-2013).]
