Lacks power, sometimes hard to start, black smoke

Tiny
DADBOY
  • MEMBER
  • GMC SAFARI
I have a 1994 GMC Safari Van, Z engine, with 103,000 miles on it. It began a month ago. It started O.K, but jumped/hesitated like an old car used to do when the choke was stuck shut. I limped it along a few days and then it wouldn't start at all. I replaced the fuel pump & strainer, fuel filter, air filter, spark plugs, 3 vacuum hoses (only one was noticeably bad), and 2 days ago had the catalytic converter cut out and a straight pipe put in. It runs better, but lacks power, sometimes is hard to start (I have to floor it to start it), and it emits black smoke.
Friday, June 9th, 2006 AT 8:57 PM

4 Replies

Tiny
BURRBRIAN
  • MECHANIC
  • 158 POSTS
The black smoke makes it sound like you are getting too much fuel. Also if you have to hold the gas pedal down to start you are flooding. Too much fuel will seem like not enough a lot of times. Are you running a carb or are you fuel injected? If you are injected you shouldn't have to touch the pedal to start. I bet you are getting crappy mileage? Check your fuel pressure and see if it is too high. Good luck.
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Tuesday, June 13th, 2006 AT 7:27 AM
Tiny
FASTED116
  • MEMBER
  • 2 POSTS
Sound you have a sticky choke get some carb cleaner and spray on carb and clean choke on car. Your eletric coke may not be working proberly (it sticking closed thus running rich) but check your choke on your carbuator if it is carbuated
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Tuesday, June 13th, 2006 AT 11:10 AM
Tiny
DADBOY
  • MEMBER
  • 4 POSTS
Yes, it is fuel injected, but it acts like a flooded carburator type engine would do.
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Tuesday, June 13th, 2006 AT 9:47 PM
Tiny
DADBOY
  • MEMBER
  • 4 POSTS
This reply may help someone with the same problem. I had a mechanic connect a diagnostic scanner while the van was running. He said the reading indicated the temperature sensor to the computor was bad. I said, "I already replaced that". He said, "There are 2 temperature sensors on this engine". He replaced the sensor and it fixed the problem. Sep. 2, 2006
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Saturday, September 2nd, 2006 AT 8:51 PM

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