Hey,
I am looking at a 1996 GMC box truck. It claimed not to run, but when I visited the seller I was able to get it started. However, it was pouring out a good amount of grey/black smoke and smelled like it was running very rich. It would also stall out almost immediately when put in gear.
Anyone know how to fix this?
2007-12-30 14:46:21 · 8 answers · asked by Svidrigailov 2 in Cars & Transportation ➔ Maintenance & Repairs
Forget the sticking choke since a 96 350 TBI does not have one. The most likely cause is a bad oxygen sensor. It could be unplugged or just needing replacement.
2007-12-30 15:04:53 · answer #1 · answered by Ken E 6 · 0⤊ 0⤋
Without being there, I'd say black smoke is too much fuel.
Could be some cylinders not firing, too, but you didn't say if it misses or stumbles.
If you can pull the plugs, look and see what they're like. Too much black, sooty coating is a too-rich mixture. Black and oily means oil is getting up into the combustion chamber. The last common thing is white or grey smoke that means water is getting combusted. This frequently means a bad head gasket.
You can try taking the air filter off, see if it runs a bit better. But the main thing is to find what's happening. From what you say, it could be a stuck choke or a blown head gasket. Can't say from this distance.
2007-12-30 14:56:48 · answer #2 · answered by going_for_baroque 7 · 0⤊ 1⤋
Kind of need more info...I thought GM went to multi-port Vortec in the trucks in '96 and also, if it is a TBI, they don't have a MAF sensor. Definitely running rich, could be a faulty MAP sensor. Would have to watch it on a scanner. Also could be a bad fuel pressure regulator if TBI.
2007-12-30 16:03:15 · answer #3 · answered by Colin W 2 · 0⤊ 0⤋
I think that the spark plugs are misfiring, resulting in improperly burned fuel, and therefore the black smoke. Misfiring also reduces power, so that might be why it stalls when put into gear. It could many different things but that's a possibility.
2007-12-30 15:05:02 · answer #4 · answered by jetengine767 3 · 0⤊ 0⤋
Sounds like an injector is stuck open in the throttle body.
Pull off the air cleaner, start the truck and look down the air horn, you would be able to see one of the two injectors pouring gas into the motor...
2007-12-30 14:51:10 · answer #5 · answered by boogie_4wheel 7 · 0⤊ 0⤋
sounds like a bum mass air flow sensor. forget a bad o2 sensor it would not cause the car to stall. If your check engine light is on and you don't have the tools to retrieve the trouble code take it to a professional.
tech for 17 years toyota, chevy and hyundia
2007-12-30 15:23:41 · answer #6 · answered by NONAME 2 · 0⤊ 0⤋
seal on the injectors is bad, 14 pounds pressure probably dripping gas, pull the cover and start it up.it should be a funnel shaped spew of gas on both sides. any dripping is bad.the reseal kit is 4 o-rings and 2 steel holdown seal/washers.
2007-12-30 15:07:48 · answer #7 · answered by jay p 4 · 0⤊ 0⤋
agree with everyone fuel mixture
2007-12-30 15:00:54 · answer #8 · answered by mike w 4 · 0⤊ 0⤋