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Hi, I've a 1992 GMC G2500 with a 5.7 350 engine. The

Sent to Car Experts June 13, 2006 8:44 p.m.

Hi, I've a 1992 GMC G2500 with a 5.7 350 engine. The vehicle sat unused for over a year. But, after a trickle charge she fired right up. I've put approximately 60 miles on it. It's gotten new brakes, fluids and an iol change. Here's the problem, drove the vehicle about 15 miles on a highway, at speeds around 70, good accelleration. But, once I stopped the vehicle and turned it off. Here's the where the problem starts, VERY VERY rough idle and almost NO acceleration capabilty. Maybe 10 MPH. She starts and will idle with some help on the pedal. I changed the fuel filter thinking it might have plugged from the OLD gas that has been in it. Still runs VERY rough on idle, but, alittle better. It will stall when you place it into any gear. Suggestions? Fuel pump? Soiled plugs? Fuel injectors? Or just the end of a REALLY OLD tank of gas? Hate to tow this to my mechanic without first trying something first. Thoughts? and thanks very much for your time. Really like this site.

Mike

Customer (name blocked for privacy)

Status: Closed Value: $15

Answer
June 13, 2006 8:56 p.m. (12 minutes and 40 seconds later)

REPLIED

Hi Customer (name blocked for privacy). Thank you for asking your question on Just Answer.

You can look at the injector spray patterns they should be very conical in shape like an upside down cone. If the pattern is broken or erratic then you should suspect a fuel pressure problem(pump,line blockage,injector blockage). You should add fresh gas but do not top it off in case you have to drop the tank. It would be a good idea to do a tune up on the truck either way, "if you plan to keep it tune it". These older style pumps were not horrible about going out but you have to think about the fuel that set in the tank, lines and injectors. It may take a few tanks of fuel before the result are known.

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Reply to Danny
Sent June 13, 2006 9:11 p.m. (14 minutes and 56 seconds later)

Makes sense on the injectors and tune up. Do you have "temporary" fix for me to get this thing to the shop? 5 miles. Injector cleaner and a gallon of 93 Oct shouldn't hurt, right?

Thx

Customer (name blocked for privacy)

Answer
June 13, 2006 11:37 p.m. (2 hours and 26 minutes later)

ACCEPTED

You are correct it will not hurt to use cleaner and higher octane fuel. I would try to drive it around for a while before I took it into the shop though it could straighten itself out.

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Danny -- Shop foreman -- 99% Positive Feedback on 331 Car Accepts
Senior Master Subaru, G.M.Cert.,Honda cert., Dodge Cert., Ford Cert., 2 ASE Master cert.15 yrs exp.

Reply
Sent June 14, 2006 10:04 p.m. (22 hours and 26 minutes later)

Relist: I still need help.
I dropped 2 fresh gallons of gas and some injector cleaner. No change. The idle is really rough, almost sounds like it's cycling itself as it idles. If I stand on the gas pedal it will RPM up very high. But, it won't keep and idle and as soon as I drop it into gear it stalls. Vacuum?

Customer (name blocked for privacy)

Answer
June 15, 2006 7:14 a.m. (9 hours and 9 minutes later)

REPLIED

Look at the injector spray patterns they should be very conical in shape like an upside down cone. If the pattern is broken or erratic then you should suspect a fuel pressure problem(pump,line blockage,injector blockage). Have you checked or replaced the spark plugs yet?

__________________
PLEASE -Remember that your Expert will not be paid until you accept an answer and complete the process. Please leave "FEED BACK".

Danny -- Shop foreman -- 99% Positive Feedback on 331 Car Accepts
Senior Master Subaru, G.M.Cert.,Honda cert., Dodge Cert., Ford Cert., 2 ASE Master cert.15 yrs exp.

Reply to Danny
Sent June 15, 2006 8:35 a.m. (1 hour and 21 minutes later)

Not yet. I'm gonna have a pro look at it. Too many possibilities here. And without the right dianostics tools, I'd just be getting the spark plug wet. If you get my meaning. :O) Mike

Customer (name blocked for privacy)

Answer
June 15, 2006 9:31 a.m. (56 minutes and 8 seconds later)

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Danny -- Shop foreman -- 99% Positive Feedback on 331 Car Accepts
Senior Master Subaru, G.M.Cert.,Honda cert., Dodge Cert., Ford Cert., 2 ASE Master cert.15 yrs exp.

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