No power

1991 CHEVROLET 1500
200,000 MILES • 5.7L • V8 • 2WD • AUTOMATIC
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FELIPE501
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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
Mar 15, 2019 at 6:37 AM
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ASEMASTER6371
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Good morning.

what did you set the ignition timing to?

Is this a new engine or used engine?

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

Roy
Mar 15, 2019 at 10:49 AM
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FELIPE501
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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
Mar 15, 2019 at 11:09 AM
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ASEMASTER6371
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You are welcome.

Always glad to help.

Roy
Mar 15, 2019 at 11:18 AM
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FELIPE501
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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
Mar 15, 2019 at 6:21 PM
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ASEMASTER6371
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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
Mar 15, 2019 at 6:22 PM
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FELIPE501
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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.
Mar 16, 2019 at 6:02 AM
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ASEMASTER6371
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You are welcome.

always glad to help.

Roy
Mar 16, 2019 at 6:07 AM
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FELIPE501
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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.
Mar 17, 2019 at 12:30 PM
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ASEMASTER6371
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Why are you changing the timing?

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

Roy
Mar 18, 2019 at 5:07 PM
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FELIPE501
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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.
Mar 19, 2019 at 5:40 AM
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ASEMASTER6371
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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
Mar 19, 2019 at 5:52 AM
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FELIPE501
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Yes, I did it right. now the timing is set at 8 BTDC.
Mar 19, 2019 at 5:56 AM
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ASEMASTER6371
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12 is a good setting.

It will make the engine run much better.

Roy
Mar 19, 2019 at 6:01 AM
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FELIPE501
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Okay, I will set that today, and will let you no what happen. And see if it backfires are not. thanks
Mar 19, 2019 at 6:13 AM
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ASEMASTER6371
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You are welcome.

Roy
Mar 19, 2019 at 6:23 AM
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FELIPE501
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Okay Roy, set the timing on 12 degrees. test drove it lack of power, like no fuel maybe. let me know, thanks.
Mar 19, 2019 at 12:19 PM
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ASEMASTER6371
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what is the timing when it is running without it being in base timing?

Roy
Mar 19, 2019 at 12:28 PM
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FELIPE501
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I will check that and let you know.
Mar 19, 2019 at 1:10 PM
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ASEMASTER6371
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Sounds like a plan.

Roy
Mar 19, 2019 at 3:00 PM
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FELIPE501
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Timing mark is about two inches to the left from the 12 degrees mark, to the driver side. let me know
Mar 19, 2019 at 4:52 PM
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ASEMASTER6371
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So it is more advanced than the 12 degrees?

Roy
Mar 19, 2019 at 5:07 PM
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FELIPE501
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Sorry Roy, I said it wrong. to the left toward the passenger side.
Mar 19, 2019 at 6:16 PM
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ASEMASTER6371
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I do not think the ECM is setting the advance correctly.

Roy
Mar 19, 2019 at 6:19 PM
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FELIPE501
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Could you tell what else I can do? Thanks Roy
Mar 19, 2019 at 6:20 PM
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ASEMASTER6371
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Do you have a scan tool that can read the OBD1 system? As I stated, I think the ECM is not controlling timing. It should be raising up to around 30 degrees with it running and driving.

Roy
Mar 19, 2019 at 6:31 PM
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FELIPE501
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No I don't have that scan tool.
Mar 20, 2019 at 5:29 AM
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ASEMASTER6371
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You need to find someone who has one so you can see what is going on with the timing.

Roy
Mar 20, 2019 at 5:32 AM
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FELIPE501
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Okay Roy, I will try to get one, then I will let you know what happen. thank you so much for your help. I will keep in touch with you later.
Mar 20, 2019 at 6:50 AM
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ASEMASTER6371
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Sounds good.

Always glad to help.

Roy
Mar 20, 2019 at 7:00 AM
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FELIPE501
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Roy, here while back we text each other about my timing in my 1991 Chevrolet truck 350, I found the problem, it was the fuel pump an the tank, remove it an replace both. the old one was so dirty an lots of corruption on the pump , filter, an the tank, now run great, So thank you so much for your help, we did it together.
Jul 9, 2019 at 9:31 AM
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ASEMASTER6371
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You are welcome.

Always glad to help.

Roy
Jul 10, 2019 at 7:35 AM