What could it be.......

[Wilecoyote]

EDIT Days ago I cranked the 98 K1500 5.7 Vrtk and let hit run on the 27 morning.Ran a mile to the gas station and bought some dip w the motor running.It was warmed up and as I left it I had stop for a light. At idle it was stumbling and about to die.Turned around and went back home.It ran down the road well but when I stopped at home is was stumbling and rpms about 400/500rpm.I got out and smelled gas, went to the tailpipe and steam and heavy gas smell. A scan yesterday had a p0174 and p0300.I took the the dizzy cap of and it had some corrosion on the contacts. Replaced the cap and rotor w ACD parts and it seem to be good idling for 5 mins. Went up the street turned left and ran about 55 for a 1/2 mile went to turn around and it was about to die while idling.Drove back home and parked it. It was stumbling and fuel smell in the exhaust the tailpipe was dripping water, but its done that since I bought it until it gets hot.The exhaust is original. W it idling I can hear a PSSSH sound like a compressor venting now and then.After i shut it down i can hear a loud TINK /ping sound about ever 10/20 seconds coming from the top of the engine. Does anyone know what might be the problem?

 

[Wilecoyote]

Does a TPS sensor have a spring in it?

well the new one does, the old one was broke and the twisty thing was wobbling around it the housing.

 

[thinger2]

Yep, the TPS has a spring in it.
The Tink/Ping is probably just the engine cooling.
Probably
Water dripping out the tailpipe on a short partially heated run is normal.
Raw gas smell aint normal.
Not out the tailpipe or anywhere else.
Emissions systems are designed to prevent fuel vapor from escaping to atmosphere
Is it an actual raw unburnt gas smell or just exhaust?
If you are actually smelling unburnt gas at the tailpipe you are running way way to rich and are washing the oil off of the bearings and the cylinders.
And there is always a possibilty of an exhaust/ cat fire to think about too.
There is a reset/relearn procedure you need to follow when replacing the TPS or pretty much any sensor.

 

[Schurkey]

A scan yesterday had a p0174 and p0300.

Reading codes is not a "scan". If you'd have looked at the data stream, the faulty TPS would almost certainly have stuck out like a sore thumb. It would be worth looking at the data stream now, to verify the rest of the sensors, the fuel trims, etc.

If you are actually smelling unburnt gas at the tailpipe you are running way way to rich

"Too rich" results mostly in increased carbon monoxide (CO) emissions. CO is colorless and odorless.

MISFIRE for any reason--too rich, too lean, or anything else--results in eye-burning, "gasoline"-smelling tailpipe emissions. That cylinder's load of fuel goes out the exhaust valve without burning.

A failed catalyst--for any reason, but misfire will kill a catalyst--will also result in some stench at the tailpipe.

 

[Wilecoyote]

The oil doesn't smell of gas on the stick, some from the filler.I'm hoping it's a misfire/dead plug or wire.Gonna pull them and check them. What is the procedure for the reset? pull the positive cable of the battery for a while?

 

[Wilecoyote]

Reading codes is not a "scan". If you'd have looked at the data stream, the faulty TPS would almost certainly have stuck out like a sore thumb. It would be worth looking at the data stream now, to verify the rest of the sensors, the fuel trims, etc.


"Too rich" results mostly in increased carbon monoxide (CO) emissions. CO is colorless and odorless.

MISFIRE for any reason--too rich, too lean, or anything else--results in eye-burning, "gasoline"-smelling tailpipe emissions. That cylinder's load of fuel goes out the exhaust valve without burning.

A failed catalyst--for any reason, but misfire will kill a catalyst--will also result in some stench at the tailpipe.

Got's the stench of fuel and something else like rotten eggs.

 

[stutaeng]

Probably the spider injectors malfunctioning, but need to properly diagnose.

Are they the original?

 

[Wilecoyote]

I'm sure they are.Bought it last year w 113k.I pulled the TB and cleaned it after a few months and the hoses looked old and everything in the intake was brown but not a lot of gas smell. In hindsight I should of removed the TPS before I turned the plate wide open in the TB.

 

[Wilecoyote]

A neighbor let me borrow his Autel OBD II tonight. I will play w it tomorrow.

 

[stutaeng]

I would check for fuel pressure with a guage. Should be like 58 psi minimum with engine off, key on.

Usually, fuel delivery problem would cause a P0171 and P0174, lean on bank 1 and bank 2. Both.

Lean on one side or the other is most likely an injector problem and/or vacuum leak.

Look for any broken vacuum hoses. You can *cautiously* spray some carb cleaner around engine and listen for engine rpm change. If you find one, you found the vacuum leak.

Injectors can be checked by doing an injector balance test, but requires more advanced diagnostic tools.

 

[stutaeng]

Does that Autel have live data? Can you pull up the fuel trims for bank 2?