1991 Problems

[bobbarker123]

I have a 1991 lumina with a 3.1 V6 it has about 198,000 miles on it. The car run really really well when driving BUT when i come to a complete stop it idles like shit and i get a strong gas smell and sometimes it might die it does it when hot or cold. the car will be fine until it comes to a complete stop. things i have done: replaced fuel pump, ignition module, coil packs, egr valve, idle air control valve, crank sensor, fuel filter, air filter, intake gasket upper and lower included valve cover gaskets and 4 of the injectors rubber o-rings. i also replcaed all plugs and wires. i can not think of anything else possible that it would be.. i need help please

[maxwedge]

Welcome to AF, besides all these parts what have you done to " actually' find out what is wrong? Try disconnecting the egr, or cleaning the pintle, check for vacuum leaks, check fuel pressure, check for fuel getting into the fp regulator hose? Scan it for sensor activity, fuel trims?

[bobbarker123]

Originally Posted by maxwedge

Welcome to AF, besides all these parts what have you done to " actually' find out what is wrong? Try disconnecting the egr, or cleaning the pintle, check for vacuum leaks, check fuel pressure, check for fuel getting into the fp regulator hose? Scan it for sensor activity, fuel trims?

I replaced the egr valve and sprayed carb cleaner inside the throttle body the fuel pump has just been changed and they only code i got was 14 which i believe is a coolant sensor, however code 35 has came up before but then went away also 44 did to and went away and same with 62 so yeah im confused

[maxwedge]

Coolant temp sensor can cause a rich condition, again a scan will tell you,

[bobbarker123]

Originally Posted by maxwedge

Coolant temp sensor can cause a rich condition, again a scan will tell you,

There are times where i will scan for codes myself with the paper clip and it wont pick up anything and there are times it will.. my engine light will go off and on if i push the gas down light will come on if i let off after a bit it will go off and just do the same repeatdly

[maxwedge]

You are not " scanning" this will not allow you to see into the pcm, a fulll scan to look at sensor inputs is the only way to avoid " guess" work and unecessary parts replacement. You may have to have a shop do this for you.

[bobbarker123]

Originally Posted by maxwedge

You are not " scanning" this will not allow you to see into the pcm, a fulll scan to look at sensor inputs is the only way to avoid " guess" work and unecessary parts replacement. You may have to have a shop do this for you.

[richtazz]

IT sounds like a sticking TCC solenoid. This solenoid locks the torque converter at highway speeds for improved mileage. When they stick on, the car will buck and lurch as you come to a stop until the car finally dies. It's similar to coming to a stop in a stick shift without pushing in the clutch or putting the trans in neutral. Your car has 2 different trans possibilities. One is electronic, the other not. If you have the 4-wire trans connector (indicating the non-electronic trans), just unplug it and see if the car stops stalling (this will disable the torque converter lock-up function). If you have the 6 wire connector (indicating the electronic trans), you cannot just disconnect it as this harness also controls shifting. I've read somewhere on these forums before that you can disconnect one of the pins on the 6-wire connector to disable the TCC, but I don't know which it is (sorry).

[bobbarker123]

Originally Posted by richtazz

IT sounds like a sticking TCC solenoid. This solenoid locks the torque converter at highway speeds for improved mileage. When they stick on, the car will buck and lurch as you come to a stop until the car finally dies. It's similar to coming to a stop in a stick shift without pushing in the clutch or putting the trans in neutral. Your car has 2 different trans possibilities. One is electronic, the other not. If you have the 4-wire trans connector (indicating the non-electronic trans), just unplug it and see if the car stops stalling (this will disable the torque converter lock-up function). If you have the 6 wire connector (indicating the electronic trans), you cannot just disconnect it as this harness also controls shifting. I've read somewhere on these forums before that you can disconnect one of the pins on the 6-wire connector to disable the TCC, but I don't know which it is (sorry).

i know for a fact its not the TCC solenoid because if it was it would surge and die when i hit the gas... and plus i already have it unplugged its been unplugged for bout 4 months now cause it was sticking. but thanks anyways

[bobbarker123]

what the car is doin is when i come up to a stop the car is fine but right when i stop it idles like shit and i get a strong gas smell and "SOMETIMES" it will die. but other then the idling the car runs perfect. it has 198,000 miles on it but i think the engine has been replaced cause of how strong the engine is

[bobbarker123]

i think i know what it is... i had the car running and i put my ear close to the manifold and i can hear air getting sucked in from somewhere under the upper manifold... so my next step is to take the manifold off and see if one of the lines has a crack in it.........

[richtazz]

That was going to be my next suggestion. There is a big vacuum line that runs under the upper plenum that supplies vacuum to the PCV valve and MAP sensor.