Running Rough Help!!!

[jhef83]

I recently bought a 92 bonneville SSEI. The gas guage is way off. I found out after running it out of gas twice. Anyway the car started missing last week.It was intermittent on the way home now it's all the time. I pulled the plugs and they smell of gas and are pretty black. I changed plugs and wires, didn't help. Manifold vacuum is 15" Fuel pressure is 41# doesn't drop when motor started. Coils ohm out at 5.5 roughly.Air filter is new. Car starts fine but after about 5-10 seconds starts sputtering won't gain RPM and back fires if you hit the gas hard.Exhaust smells kind of gassy but no smoke. I'd like to pull some codes but check engine light must be burnt out. Never comes on. Any help would be greatly appreciated.

 

[jhef83]

Well I replaced the fuel pressure regulator this morning, pressure went from steady 41# at idle too an erratic 30#-50# at idle. Still 41# key on engine off. Bad regulator? Went and got another. Think I'll wait till tomorrow to try it.

 

[suicide six]

O2 sensor could cause this.

 

[jhef83]

If I understand right the fuel pressure should drop 10# or so after engine starts so long as theres no vacuuum leaks. I got 15" at the regulator hose, So I'm assuming the regulators bad. I hate being a parts changer, but I'm heading in that direction. I'll know more when I start it tomorrow.

 

[JasonGS]

Sorry, I can't be of much help on the Series I. On the Series II, that is right where the fuel pressure should be (~40-42psi at idle). I will fluctuate with changes in MAP values.

The fuel pressure drop you're talking about is if you have the vac line disconnected (and plugged), it should read close to 52 psi. It shouldn't drop from key on to starting with the vac line connected to the fuel pressure regulator.

 

[jhef83]

Thanks for the replies guys. Yea the second regulators acting the same. So that rules it out. I guess I'll pull the dash apart and change the check engine bulb and get some codes.

 

[jhef83]

Well pulled the dash apart and bulb is good. Somebody [Dealer] sabotaged the light maybe. Went ahead and put a known good bulb in anyway. No light. Probably pull ignition module next and have it checked. This is getting old.

 

[jhef83]

I took the ignition module to Autozone. They say it's good. The scan tool for this car runs well over $300 and they don't rent one. The counter guy suggested unplugging sensors to see if idle improves. I unplugged MAP and tried to start car, didn't start. Hasn't started since. I've got no spark now. I've got 12v to the module from fuse block. I'm about ready to go ahead and try another module. My brother in law thinks it's the crank sensor, I hope not I can barely see it. Looks like it would be a real joy to change. Any other educated guesses would be greatly appreciated. One other thing when I put instrument cluster back in I forgot the metal plate that goes on the back. I think it just helps hold the connectors in though. Or if it's a ground for the cluster... All the guages work though. This has went from bad to worse.

 

[Metalmanimal]

Running Rough

Did you check your Engine coolant sensor? I have seen them get skewed to -30 degrees which would make the car dump way too much fuel.if you unplug sensor
it should default to 50 degrees.If the connector has a bunch of green stuf on it that is definately your problem.providing all other things like compression,Ign Etc is good.
Just My Two Cents Worth
Good Luck

 

[jhef83]

I'm having some trouble identifying sensors. Not much support for bonneville. If I find it I'll try it, Thanks

 

[jhef83]

Crank Sensor

I'm having some trouble identifying sensors. Not much support for bonneville. If I find it I'll try it, Thanks

I found the crank sensor loose today. I pulled the balancer and the sensors all chewed up. There was a little square magnet about 3\16 stuck to the balancer. i think it was part of the sensor. May have found the problem.

 

[jhef83]

Success

It was the crank sensor. Replaced it and it fired right up.

 

[Metalmanimal]

Running Rough

Excellent!! That sensor must have been hit by something to be that messed up.Usually they dont fall apart like that...Good Luck..