Mustang5L5’s progress thread - fuel pressure shennanigans SOLVED

Hmm. I’ll have to sit back and see how popular these become. I like them, and then I also don’t in some views.

I just wish I could get my current wheel in a 9” wide and I’d be happy
 
I was just thinkin' the same thing. There will be 50 cars with them at foxtoberfest this year. They look great, but everyone will think so, too.

Feels like you have to go to other circles to find something a little more unusual.
 
There are several places that can widen them. I know you are pretty picky so just throwing g it out there.
Which company is the best to go with on widening wheels? General cost?

Been toying with the idea of having 2 of my S197 wheels stretched out when it comes time for new tires. I'd like to get some 275/40's on the rear.
 
I think it was $250ish a wheel when I inquired several years back with weldcraft. Costs could have gone up since. Didnt include shipping costs or repairs/refinishing if necessary.

Could have gone up since then.
 
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Probably the most well known one is Weldcraft. I will say that you need to clean the wheels up really well and take very good pictures at all different angles. I have seen a couple instances where they say a wheel needs to be repaired. Couple were wheels were sent that needed to be fixed. couple were shipping damage, and most were "I didn't have pictures of them before they shipped so I have no idea". Other thing is if they say it needs to be fixed ask for a detailed explanation from them as to why and pictures showing what needs to be fixed. If the wheels were fine before then its up to you to have them fix it or just widen it and move on. If the damage prevents them from getting it into a welding jig then its fix the wheel, find another wheel, scrap it and eat the loss, or have them ship the wheels back.

This is all worst case scenario as I have seen hundreds of wheels widened by them and they are money. Weldcraft is not the only one so do some research.
 
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Ok back to main topic.

Tossed some gas in the car and fired it up. Sounddd nice and healthy after the winter slumber. Had to set the fuel pressure reg and then started logging and gave it some throttle blips.


Same damn thing. Drops to 27-29psi and goes lean.

So…looks like it wasn’t the wiring. Well, it’s upgraded anyway now.

So looks like next thing on my list is to swap the fuel pump.

She sounds good though


View: https://youtu.be/rgr3k6RBd-M?si=Q2OqkrIXjSiuSHLT
 
That blows. Probably a worthwhile upgrade anyway.

Just to play devils advocate, what if these two things aren't related? Would FP of 27-29 psi cause a lean condition with no load in neutral, I wouldn't think so. It's possible of course. But I'd think you could have seriously low FP and still have enough fuel to run properly under no load.

Of course you have to fix the FP becasue something ain't right there. But is it causing the lean condition? That's the question I guess.

You'll figure it out. It's alot easier to get stuff done when the weather breaks. It's finally happening here!
 
That blows. Probably a worthwhile upgrade anyway.

Just to play devils advocate, what if these two things aren't related? Would FP of 27-29 psi cause a lean condition with no load in neutral, I wouldn't think so. It's possible of course. But I'd think you could have seriously low FP and still have enough fuel to run properly under no load.

Of course you have to fix the FP becasue something ain't right there. But is it causing the lean condition? That's the question I guess.

You'll figure it out. It's alot easier to get stuff done when the weather breaks. It's finally happening here!

Last fall when I was driving the car, it was running lean on WOT pulls. I had to dial in a lot of fuel into my VE table. Enoigh that it seemed excessive.


One other test I did today was to pull the vac line off the regulator and cap it. Wanted to take the vac diaphragm out of the picture. Static at 39psi. Blipped the throttle and dropped to 32ish.

I did peek in the tank with the pump running from the fill port. No leaks or split hose so that’s ruled out.
 
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Guess we're ready for a fuel pump, now.

I have one. Got one from @Kid wita 5oh tonight.


Need to find time to swap this in and see what happens. If that doesn’t solve it, I need to start looking for a restriction in the lines somewhere. Saved that for last because in my mind it’s the least likely, but can’t rule it out.
 
Swapped the pump. Fired it up.

No dice. DIdn't make a difference. Same exact thing. I played with it a little bit but essentially I got the same darn numbers. Any sort of blip on the throttle and pressure drops.

Not sure what else it could be. At this point it could be a blockage. It would have to be ahead of the pressure gauge, as a blockage after that wouldn't register the pressure drop I assume. SO i need to blow out the main feed line from the fuel filter to the soft line connect on the pass side. I can't rule out debris in the lines. WHen i rebuilt the engine I stuffed some rubber plugs inthe lines. I can't guarantee all of it came out. It's also possible whatever debris was there jammed itself in the hard line with the pressure port just ahead of it.

Need to stop and think about this a bit more....

There are physical symptoms. The engine stumbles when I blip it.

Blue line is where i stab the gas. Pressure drops off, engine rpm drops, AFR goes to 19 shortly after. EVery time i blip the throttle i get the stumble.

1776115155537.webp
 
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Holy cow... That sucks. At this point, I'd be inclined to buy rubber hose and bypass the fuel lines to recheck that everything else is fine, and that the part of the line you're bypassing contains the crimp or blockage.

Starting to make me wonder if it could be more than one part.
 
At this point I threw the tank back in the car. Just need to crimp up the weatherpack connector on the wiring and organize it nicely and take a break.

Im dejected for now. Thought I had it. Just gonna pull the car out in the sun warm the engine up and give it a wash and change the oil while I think about this a bit.
 
Are you sure there arent two issues here? The FP dropping is an issue to be sure, but for the blip, is the accel enrich set up right? That would cause an instant lean and stumble condition.