loss of power when accelerating

MikeUCFL

Since covid hit, my Z has been rarely driven. I took it out today and when starting in first gear there was a huge loss of power when trying to accelerate (even at 10% throttle), felt like I applied the brakes almost. There are no CEL's on, however I want to say the last time I filled up may be a year ago with 93 octane. I'm assuming it could be bad gas, so my thought is to use something to siphon out the gas and put some fresh 93 in, but not sure what else I should check. Possibly the fuel filter as well? Just looking for some ideas/thoughts to check.

Some more notes:
- I could rev the engine in neutral fine, seems to happen under load
- Mainly happened in 1st gear, either at low throttle or full. I could put it in 2nd or 3rd and step on it and the car seemed fine.
- The car would engine brake really badly when accelerating, and then snap back and take off.

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Magnetic Black Touring/Sport/Navi/6MT < Stillen G3 | ZSpeed Stage 1 Clutch/Flywheel/CMAK | RJM Rev 3.2 Pedal with Tilton Master

Spooler

No fuel filter on the stock car. Drive the fuel out and fill up with fresh fuel. See what happens. How old are your tires, if you had traction control on it may have cut the throttle due to traction issues. They may have been what you felt.

MikeUCFL

Ah didn't realize there was no fuel filter. My tires are about a year old. Traction control was on, but most of the time I was barely pressing the throttle when it happened (normal driving). In any case I'll try turning it off and see if there's any difference.

Another note I forgot to mention, about a month ago I drove it on the highway for about 20 miles and I went from 1/4 tank to 1/2 tank. Really strange. I had the fuel sending unit replaced under warranty about 8 years ago, wonder if it has gone bad again.. or could bad fuel cause it to flake out as well? It seems to like to stay at half tank right now even though I drove it maybe another 20 miles since, miles left in tank fluctuates from 149-153 miles.

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Magnetic Black Touring/Sport/Navi/6MT < Stillen G3 | ZSpeed Stage 1 Clutch/Flywheel/CMAK | RJM Rev 3.2 Pedal with Tilton Master

redondoaveb

I wonder if the top hat has broken on your fuel pump

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Fast Intentions "Stage Seb" twin turbo #098- Specialty Z/Tial-Xonarotor/CJM/Ecutek/HKS/KW/SPL/Hotchkis/Rohana/Toyo
700+whp

Spooler

That is what it sounds like. The top hat broke off the fuel pump assembly.

MikeUCFL

Thanks guys, after reading some it does seem like this could be the cause.

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Magnetic Black Touring/Sport/Navi/6MT < Stillen G3 | ZSpeed Stage 1 Clutch/Flywheel/CMAK | RJM Rev 3.2 Pedal with Tilton Master

Tractionless

Nissan considers the pickup sock on the bottom of the pump the fuel filter. I've yet to see a auxiliary fuel filter (mod) added to the OE system.

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Toys Not Tots

phunk

There is a fuel pump strainer which is a prefilter, and then there is a post-pump low micron filter. The filter is inside the white plastic fuel pump housing, and it is not serviceable or replicable without replacing the entire fuel pump housing... but it is in there. If you look at a stock fuel pump assembly, the hose leaving the electric fuel pump itself is a 180 degree bend... it goes from the pump to the filter inlet. Then opposite of it is the filter outlet to the plastic top hat.

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