Running rich
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Running rich
Put aside the fact that I have a cavalier, and dont say "buy a new car", my car is basically new and has a warranty....this is for my other car. (94 Cavalier 5spd 3.1L V6)
For the record, I just had the heads milled and acid bathed, replaced the head gaskets, lower valleypan gasket, intake plenum gasket, EGR and EGR gasket, throttle body gasket, valve cover gaskets, exhaust manifold gaskets, sparkplugs (plug wires are fine), O2 sensor, alternator, starter, air filter, new oil and antifreeze, if that even matters.
I have taken the injectors/fuel rails out and checked the o-rings (all were fine) and cleaned what I could. With the IGN on, the fuel injector sensors tests all in the same area in terms of Ohms, but this was not with the car running. No codes are being thrown. No Valve tick. All rocker arms, lifters, and rods are fine.
Heres the symptoms:
-white smoke at from exhaust at cold temp, no smoke at operating temp.
-VERY potent gas smell from the exhaust, along with LITTLE water and black soot.
-No smell of gas from around the fuel rails and injectors.
-Idles beautiful at cold temp, moderatley rough at operating temp.
-Has a slight misfire/hesitation feeling at 1/2 throttle...WOT is fine.
-Sparkplug on cylinder #4 has a slight amount of oil on it, the other 5 are fine.
-Smell if fuel in the gas
-Two clicks 5 seconds after the car has started.
Any thoughts? I personally think leaky injector(s),TPS sensor, or fuel pressure regulator, but I dont think that all of the cylinders are running rich.
For the record, I just had the heads milled and acid bathed, replaced the head gaskets, lower valleypan gasket, intake plenum gasket, EGR and EGR gasket, throttle body gasket, valve cover gaskets, exhaust manifold gaskets, sparkplugs (plug wires are fine), O2 sensor, alternator, starter, air filter, new oil and antifreeze, if that even matters.
I have taken the injectors/fuel rails out and checked the o-rings (all were fine) and cleaned what I could. With the IGN on, the fuel injector sensors tests all in the same area in terms of Ohms, but this was not with the car running. No codes are being thrown. No Valve tick. All rocker arms, lifters, and rods are fine.
Heres the symptoms:
-white smoke at from exhaust at cold temp, no smoke at operating temp.
-VERY potent gas smell from the exhaust, along with LITTLE water and black soot.
-No smell of gas from around the fuel rails and injectors.
-Idles beautiful at cold temp, moderatley rough at operating temp.
-Has a slight misfire/hesitation feeling at 1/2 throttle...WOT is fine.
-Sparkplug on cylinder #4 has a slight amount of oil on it, the other 5 are fine.
-Smell if fuel in the gas
-Two clicks 5 seconds after the car has started.
Any thoughts? I personally think leaky injector(s),TPS sensor, or fuel pressure regulator, but I dont think that all of the cylinders are running rich.
Last edited by Black Z-24; 08-09-2004 at 05:32 PM.
#2
Iridium V
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Re: Running rich
Your exhaust smoke seems to be normal condensation, except for the rich smell. There are many things that could cause the car to run rich without faulty injectors. Mas air flow sensors malfunctioning telling the ecu it is passing more air than it really is, oxygen sensors telling the ecu that the exhaust gas temp is higher than it really is. A faulty ecu will also do this. Possibly a bad pressure regulator. You may want to spend the 60 bucks to have it properly diagnosed if you don't have the proper equipment to do so and save your self the hastle. Once the car is diagnosed, you can do the work yourself.
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Re: Running rich
do you have any diag equipment? GOOD fuel pressure gauge, scanner, inj tester?
if not, i would bring it in to a GOOD drivability shop. could be alot of things, but i would have too look at serial data and other things before i could accurately diagnose it.....
O2 sensor isnt going to tell the ECU exhaust temps, and if i recall, the 94 3.1 was a speed density system. GM had MAJOR issues with MAF's being bad from the factory in the late 80's, and went to a speed density (read: TPS and MAP based fuel metering)
if not, i would bring it in to a GOOD drivability shop. could be alot of things, but i would have too look at serial data and other things before i could accurately diagnose it.....
O2 sensor isnt going to tell the ECU exhaust temps, and if i recall, the 94 3.1 was a speed density system. GM had MAJOR issues with MAF's being bad from the factory in the late 80's, and went to a speed density (read: TPS and MAP based fuel metering)
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Re: Running rich
Originally Posted by fc735
do you have any diag equipment? GOOD fuel pressure gauge, scanner, inj tester?
if not, i would bring it in to a GOOD drivability shop. could be alot of things, but i would have too look at serial data and other things before i could accurately diagnose it.....
O2 sensor isnt going to tell the ECU exhaust temps, and if i recall, the 94 3.1 was a speed density system. GM had MAJOR issues with MAF's being bad from the factory in the late 80's, and went to a speed density (read: TPS and MAP based fuel metering)
if not, i would bring it in to a GOOD drivability shop. could be alot of things, but i would have too look at serial data and other things before i could accurately diagnose it.....
O2 sensor isnt going to tell the ECU exhaust temps, and if i recall, the 94 3.1 was a speed density system. GM had MAJOR issues with MAF's being bad from the factory in the late 80's, and went to a speed density (read: TPS and MAP based fuel metering)
Going to try a couple more things.
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