1993 GMC Yukon sputtering during acceleration

Tiny
JMILLER427
  • MEMBER
  • 1993 GMC YUKON
  • 5.7L
  • V8
  • 4WD
  • AUTOMATIC
  • 130,000 MILES
I just recently replaced all my plugs wires ect. On my 93 yukons 350 and in mid range rpms it seems to have a hesitating sputter and also stalling out at times I checked the times it it seems to be on from what my Haynes book suggests it to be at 0° tdc with wire on fire wall disconnected not sure what else it could be now any advice is appreciated
Friday, January 2nd, 2015 AT 1:14 PM

10 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Have you checked trouble codes? Have you checked fuel pump pressure?
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Friday, January 2nd, 2015 AT 4:18 PM
Tiny
JMILLER427
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  • 6 POSTS
No how do I check the pressure on that? I don't have any codes from no lights on dash
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Friday, January 2nd, 2015 AT 4:21 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Here are directions for checking fuel pump pressure:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Since this is an OBD1 system, the check engine light may not be on, but codes may be stored. Do you know how to check?
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Friday, January 2nd, 2015 AT 4:26 PM
Tiny
JMILLER427
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  • 6 POSTS
No I don't know how to check I'm use to non computerized autos
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Friday, January 2nd, 2015 AT 5:07 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Under the dash is a large rectangular plug. What you have to do is turn the key to the off position. Using a paper clip or wire, jump pin A and pin B. Once the jumper is between the A and B terminal on the data link connector (DCL), turn the key to the run position / engine off. The check engine light will begin to flash.

The flashes from the check engine light are codes. The codes are 2 digit numbers. For example, if the light flashes 3 times, there is a slight pause, then 7 more times, that is a code 37. There will always be a brief pause between the two digit code. There is a slightly longer pause when it changes to the next code.

If you could try this, it would help me provide better info.

Let me know,

Joe
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Saturday, January 3rd, 2015 AT 7:11 PM
Tiny
JMILLER427
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  • 6 POSTS
K I tried that n I got the normal three flash for a code 12 but then pauses for bit n flashes four times in a row not sure what that code could be? Any suggestions?
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Saturday, January 3rd, 2015 AT 7:28 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Are you sure it isn't a code 34? That would indicate a manifold absolute pressure sensor (MAP) signal is out of range. (Too Low) The vacuum hose to the sensor may be leaking or disconnected. That could cause the issues you are having.
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Saturday, January 3rd, 2015 AT 7:39 PM
Tiny
JMILLER427
  • MEMBER
  • 6 POSTS
Will check it out n see
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Saturday, January 3rd, 2015 AT 7:56 PM
Tiny
JMILLER427
  • MEMBER
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So I checked the vaccum line on the map sensor its still good now the computer is throwing a code 43 says its not receiving signal from the knock sensor? Would that do it at all I replaced the distributor all so
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Saturday, January 10th, 2015 AT 6:27 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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The purpose of the knock sensor is to fine tune ignition timing to its optimum point under different conditions. The key word is FINE TUNE. I don't feel that would cause the engine not to start. Have you checked fuel pump pressure?
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Monday, January 12th, 2015 AT 5:58 AM

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