Help with strange stalling issue.

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Jan 19, 2022 | 12:58 PM

Mrcurrence

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Help with strange stalling issue.

Hello everyone I have a 1993 f150 mark3 with a refeshed 5.8 .40 over gt40pheads, lunati cam and the old e40d. I have replaced and tested all the sensors i can think of, new fuel pump in the front tank, but im having this stalling issue when at low speed and stopping. The truck just dies like it runs out of gas. It also acts like it needs more fuel at 3/4-full throttle, almost like it hits kind of a dead spot. I am at the end of my rope and could use some advice. Only codes i get are for egr which has been deleted along with smog pump , tab, tag, tad and cat. Please any insite is appreciated before i swap a 5speed and carburetor in this thing.

Last edited by Mrcurrence; Jan 19, 2022 at 01:01 PM. Reason: Spelling

Jan 19, 2022 | 02:46 PM

Beechkid

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From: Southern California

Hmmmm. assuming the fuel filter has been replaced s well? My swag would be Fuel Pump Driver Module!

Jan 19, 2022 | 06:04 PM

Mrcurrence

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Quote:

Originally Posted by Beechkid

Hmmmm. assuming the fuel filter has been replaced s well? My swag would be Fuel Pump Driver Module!

Yes i did change fuel filter. I have a return line so no deiver on mine.

Jan 19, 2022 | 07:15 PM

xlt4wd90

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From: SoCal

Can you put a pressure gauge on he fuel rail and see what it reads? What would be ideal is if you can watch it while you drive it under load, like at 3/4 throttle opening.

Jan 19, 2022 | 07:17 PM

Mrcurrence

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Yes. It was within spec at idle i have no way to drove arpund with one hooked up

Jan 20, 2022 | 07:11 AM

rla2005

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From: Kentucky

Quote:

Originally Posted by Mrcurrence

i have no way to drove arpund with one hooked up

Then you will never know if the fuel pressure rises under load. At the very least try applying the brake and throttle to put a load on the engine. A few seconds should be enough. Watch the fuel pressure to verify it rises to ~40 PSI under load.

Jan 20, 2022 | 07:12 AM

rla2005

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From: Kentucky

What are the specifications on the Lunati camshaft you installed. Adding heads and a hotter cam will push the envelope for the factory EFI system programming.