Engine slow starting and the engine service light is on

Tiny
RUSS1953
  • MEMBER
  • 1999 CHEVROLET S-10
  • RWD
  • AUTOMATIC
  • 166,000 MILES
When cranking the engine it is slow by starting up the engine service light is on. When I plug the scan tool into the ALDL and turn the key on nothing happens, the scan tool does not show anything. What is the cause?
Friday, December 30th, 2016 AT 9:39 PM

7 Replies

Tiny
CARADIODOC
  • MECHANIC
  • 33,870 POSTS
Do you mean the engine cranks too slowly to start, or it has a long crank time before it finally starts running?
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Friday, December 30th, 2016 AT 9:46 PM
Tiny
RUSS1953
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  • 23 POSTS
It has a long crank time before it finally starts running?
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Saturday, December 31st, 2016 AT 12:21 AM
Tiny
MHPAUTOS
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Is it cranking over fast or slow? If slow starter may be pulling and drawing current this will cause ignition voltage problems and hard starting.
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Saturday, December 31st, 2016 AT 1:04 AM
Tiny
RUSS1953
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It is cranking over fast.
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Saturday, December 31st, 2016 AT 11:08 AM
Tiny
CARADIODOC
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The best suspect is fuel pressure is dropping when the engine is off. It should stay up for days or weeks. To verify this, turn the ignition switch on, wait for two or three seconds, (you might hear the hum of the fuel pump for one second), turn it off, wait a few seconds, then turn it on again and crank the engine. If that helps, it's because fuel pressure needed to build up enough for the engine to run. The pump runs slower than normal during cranking, so pressure builds up slower.

The best suspect for losing fuel pressure is a leaking injector, but a leaking fuel pressure regulator or a leaking check valve in the fuel pump can do that too. You can connect a fuel pressure gauge to see what happens to fuel pressure when the engine is off, and when you try to start it.

I will be leaving now to hibernate overnight! HMAC300 will give you some guidance if he is watching for your next reply.
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+1
Saturday, December 31st, 2016 AT 3:07 PM
Tiny
CARADIODOC
  • MECHANIC
  • 33,870 POSTS
Should have said "MPHAUTOS"! Sorry MPH.
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Saturday, December 31st, 2016 AT 3:13 PM
Tiny
MHPAUTOS
  • MECHANIC
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All good Mate, will keep an eye on it. Cheers
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Saturday, December 31st, 2016 AT 3:49 PM

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