No power

Tiny
FELIPE501
  • MEMBER
  • 1991 CHEVROLET 1500
  • 5.7L
  • V8
  • 2WD
  • AUTOMATIC
  • 200,000 MILES
When Idle the engine run fine, an even if when I throttle all the way down run with power, but when I test drive it, seen like no gas to the throttle body. I check the pressure to the fuel pump an it is 11 LBS. I have replace the fuel pump, filter, new fuel line, new pump relay, fuse, new distributor, spark plugs an wires, new computer, map sensor, throttle sensor, Idle air control valve, new gasket set with seals for throttle body. I cut the pipes before it goes to the catalytic converters so the pipes are clear. If you could figure the answer to my problem you would be my friend for ever. I have been working with my truck for two years now. I install a new engine, new everything I can think of. Thank you
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Friday, March 15th, 2019 AT 6:37 AM

33 Replies

Tiny
ASEMASTER6371
  • EXPERT
Good morning.

What did you set the ignition timing to?

Is this a new engine or used engine?

Roy
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Friday, March 15th, 2019 AT 6:52 AM
Tiny
FELIPE501
  • MEMBER
Yes, set timing by ear, and yes it is a new engine.
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Friday, March 15th, 2019 AT 10:19 AM
Tiny
ASEMASTER6371
  • EXPERT
You need to use a timing light. Needs to be 8 degrees before top dead center with it in base timing mode.

Roy
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Friday, March 15th, 2019 AT 10:49 AM
Tiny
FELIPE501
  • MEMBER
Okay, I will try that. I will need to get a timing light then I will let you know something. How think work out. Thanks
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Friday, March 15th, 2019 AT 11:09 AM
Tiny
ASEMASTER6371
  • EXPERT
You are welcome.

Always glad to help.

Roy
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Friday, March 15th, 2019 AT 11:18 AM
Tiny
FELIPE501
  • MEMBER
Okay Roy. Went an bought a new timing light, and then remove the timing advance connected and set the timing according to your question, and then when I connected the timing advance, did not make a difference in the timing mark. When the floor it to the floor had a back fires on my throttle body. Do you know why? Let me know, thanks. Let me explain, the old motor had a EGR, but my new motor could not use the same intake, so had to switch intake, an the intake does not have a place for the EGR. Thanks
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Friday, March 15th, 2019 AT 6:21 PM
Tiny
ASEMASTER6371
  • EXPERT
Okay, after you set the timing, then connect the timing wire, the timing will not change until you turn off the truck and restart.

Roy
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Friday, March 15th, 2019 AT 6:22 PM
Tiny
FELIPE501
  • MEMBER
Okay, I will check the timing again Sunday, and will test drive the truck and will update results, later in the day, Thank you buddy for doing good on you helping me with my truck.
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Saturday, March 16th, 2019 AT 6:02 AM
Tiny
ASEMASTER6371
  • EXPERT
You are welcome.

Always glad to help.

Roy
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Saturday, March 16th, 2019 AT 6:07 AM
Tiny
FELIPE501
  • MEMBER
Results I set the timing 8 degrees BTDC and when test drive stall, then set to 4 degrees BTDC like it run out of gas, then set timing to 12 degrees TBDC, then better but not good still a little rough. Now what can I do to correct it? Roy, let me know.
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Sunday, March 17th, 2019 AT 12:30 PM
Tiny
ASEMASTER6371
  • EXPERT
Why are you changing the timing?

Did you set it the correct way by putting it in base timing?

Roy
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Monday, March 18th, 2019 AT 5:07 PM
Tiny
FELIPE501
  • MEMBER
I wanted to know what kind of difference it would make, but yes right now I have it to 8 BTDC, on that timing mark. When I floor board it it is backfiring through the throttle body. When I test drove it, it stalled. Don't no what else to do at this time. Any help from you will help me. Thank you Roy, sent me more information.
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Tuesday, March 19th, 2019 AT 5:40 AM
Tiny
ASEMASTER6371
  • EXPERT
You keep avoiding my question about if you did the proper procedure for setting the timing.

If you did not, the timing is way off.

Roy
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Tuesday, March 19th, 2019 AT 5:52 AM
Tiny
FELIPE501
  • MEMBER
Yes, I did it right. Now the timing is set at 8 BTDC.
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Tuesday, March 19th, 2019 AT 5:56 AM
Tiny
ASEMASTER6371
  • EXPERT
12 is a good setting.

It will make the engine run much better.

Roy
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Tuesday, March 19th, 2019 AT 6:01 AM
Tiny
FELIPE501
  • MEMBER
Okay, I will set that today, and will let you no what happen. And see if it backfires are not. Thanks
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Tuesday, March 19th, 2019 AT 6:13 AM
Tiny
ASEMASTER6371
  • EXPERT
You are welcome.

Roy
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Tuesday, March 19th, 2019 AT 6:23 AM
Tiny
FELIPE501
  • MEMBER
Okay Roy, set the timing on 12 degrees. Test drove it lack of power, like no fuel maybe. Let me know, thanks.
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Tuesday, March 19th, 2019 AT 12:19 PM
Tiny
ASEMASTER6371
  • EXPERT
What is the timing when it is running without it being in base timing?

Roy
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Tuesday, March 19th, 2019 AT 12:28 PM
Tiny
FELIPE501
  • MEMBER
I will check that and let you know.
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Tuesday, March 19th, 2019 AT 1:10 PM

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