Progress Thread My centrifugal ppl, how’s this deal?

My Glowshift gauges have been reading consistent for a couple years ( verified with megasquirt ). Looks like low fuel pressure...and the popping you heard could've been lean backfire. You'd be surprised how much air fuel ratio can change the exhaust sound.

Plugs don't look bad to me either. That oil would drive me nuts.

Your AFR seems like it's on target in the driving video. That goes against a fuel issue. I would expect to see the AFR at about 16- 17 for it to be truly running lean. When on the throttle it would climb and get worse as you put load on the engine.
So in the video when I was trying to start it you could hear it trying turn over then put put put like it wasn’t getting fuel. That’s what happened when I drove it a couple of days ago again after it just died off on its own for no reason. Then it just cranks right up. When I do start it up normally with no issues the gauges correlate then after a little cruise I notice the gauge tend to drop below 20 like it was showing. Can’t seem to figure it out and makes driving the car a very uneasy feeling bc last thing I want to do is get stuck in the middle of traffic. SUCKS!! I’m gonna pull the filter just to check it since it’s easy enough, then crank it and try pulling the line from the fuel pressure reg and see what it does. Do you think it could be losing pressure due to something electrical?
 
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Definitely sounds like a fuel supply issue. Fuel pressure is vacuum referenced so at high vacuum (idle) it should be around 30 psi. Under throttle, low vacuum, should be around 40 psi. What’s the age/history of the pump?
 
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Definitely sounds like a fuel supply issue. Fuel pressure is vacuum referenced so at high vacuum (idle) it should be around 30 psi. Under throttle, low vacuum, should be around 40 psi. What’s the age/history of the pump?
Pump was a brand new aeromotive 340 stealth. I’m guessing that even if it was new they can still go bad
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Pump was a brand new aeromotive 340 stealth. I’m guessing that even if it was new they can still go bad
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I would check the regulator. Is it stock or adjustable? I do know my adjustable one needed a ton of adjustment from the factory setting. Have you pulled the vac line to see where the psi goes? does the vac line smell like gas? what psi do you get when you just turn the key to the on position?
 
I'm not suggesting you do this right now, but something to keep in mind. Those rubber hoses that connect the pump to the hat can have issues (kinks, rips, loose clamps).

Also, looks like the fuel line mounted gauge shows 30 psi and the cowl mounted gauge is below 20? Were those pics taken with the engine running?
 
I would check the regulator. Is it stock or adjustable? I do know my adjustable one needed a ton of adjustment from the factory setting. Have you pulled the vac line to see where the psi goes? does the vac line smell like gas? what psi do you get when you just turn the key to the on position?
No it’s an adjustable kirban, in the works of cranking it and pulling the line to see what it does, as well as see what I get with just key on now that I swapped the fuel filter.
 
I'm not suggesting you do this right now, but something to keep in mind. Those rubber hoses that connect the pump to the hat can have issues (kinks, rips, loose clamps).

Also, looks like the fuel line mounted gauge shows 30 psi and the cowl mounted gauge is below 20? Were those pics taken with the engine running?
Yes the car was running as I had just got it back home after that cruise where it just cut off on it’s own and struggled to restart. Not sure why the mix match in numbers. Which was why I checked the fuel line I had spliced for the grille mounted gauge but all looked intact and no leaks.
 
Alright so I pulled the filter not sure what brand it was but i bought a motorcraft just in case. This was a new filter when I changed about a year ago. The gas that poured out when I pulled looked pretty clean and shot a small vid just to try and show. The nozzle that painted towards the passenger side seemed just slightly bent but not sure if that would really make a big difference, but since I had a motorcraft and it looked straight compared to that one I just swapped them out. Dropped the car, primed the pump a few times to get some fuel through and with just the key on my gauges were both Reading close to the same. The GlowShift read about 32psi and the line mounted was about 34psi. I cranked it on and they still read at the same numbers. So I let it warm up some and FP held the same, I pulled the line on the regulator and both gauges jumped up to 40psi. Put it back on and they dropped back to the same readings as before. Didn’t take it for a drive yet, I’ll probably do that tomorrow after work just to see how the Fuel pressure holds and whether it just shuts off again or if I get any fluctuation on the pressures again. What I did notice after all that is the fact that my rpms seemed to settle at idle to about 800 vs on my previous post where @a91what and some others were stating that it was running a little hi at 1000 during idle. I let it run for awhile in the garage and it stayed steady as far as fuel pressure readings on both gauges and the rpm at idle. Could something in that fuel filter been causing issues? Idk just strange that now the fuel pressure seemed to be reading better and now the rpms seem to have taken a slight dip.
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To check fuel filters I cover the tubes with my thumb and pointer finger and shake it. It stirs up the dirt inside. Also, you want to pour it out on the inlet side of the filter.
 
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Made it to Radwood 80s-90s car show here in ATX for the second year and it was a blast! Got up early did my checks, oils, fluids etc. and we are off. Car drove great, was a nice cool morning, no issues with idle at the stop lights, fuel pressure held up perfect, got stuck in line to get in the show car just trotted along and I was pumped to park, get some breakfast beers goin, and check out the scene. Started to warm up around 1130, but it was a great day, so many sweet rides. That was the good, time for the :poo:! So it’s about 130 and figured meh I’m gonna get rolling so I can beat this traffic out of here bc they have everyone park along the race track and I got parked way out back. Got all my stuff packed up, got in the car and crank it and guess what? It’s starts doing what it was doing previously that I mentioned and in the videos. Cranking, sounds like it wants to go and nothing. Tried a few times and decided I’m gonna let it sit for a minute bc I was frustrated, due to the fact that it had been running so great. Waited about 15 minutes, and gave it another go, and it just did the same thing, cranking and its trying and sounds like it’s gonna turn over and put put put. Kept trying and trying with no avail. Had some guys help me push it to a spot on the track where there was some shade and let it sit again. By this time some other fox body guys at the show start trying to help diagnose. Even tried jump starting it and no go. Pulled the coil plug to check spark, has spark. Pulled the cap to check the rotor etc all looks normal. Has fuel pressure around 20-25 if I remember correctly. Would turn key on and the guys would check the fuel rail gauge had about 30 and during the crank it would hold or bump up slightly. Could hear the fuel pump priming, while trying to crank over you could smell fuel. I tried and tried till about 430 at this point, everyone was gone and I was stuck on the track, so one of the track workers helped tow me up front. Gave it another go and nothing. So once again had to get it towed. Towed it to a friends shop who had helped with my top end work previously but no one was around, parked it in the lot and left it over night. Went back Sunday afternoon around 2 and shop was closed so I wanted to get some stuff out of it and decided let’s see what happens. Well guess what it cranks right up like a champ. Wtf!!!!! I decided to drive it home and once again it’s running great, get stuck at some lights and no issues. I’m so confused at this point bc I believe this is something beyond my knowledge. I talked with the shop owner, and asked about vapor lock even though I’ve heard it doesn’t happen on EFI cars. I removed all my smog emissions stuff even the canister so idk. Could it possibly be some thing with that? He was starting to think as I have noticed this seems to happen once the car warms up and maybe it could be the PCM. My plan is I’m gonna drive it for a bit this coming Saturday and run it by the shop and park and see if it will do this crap again so we can try and diagnose it when it’s actually happening vs just word of mouth. Not what I wanted to do but at this point I’d rather some one with better car knowledge than me hopefully be around it when it does this bc I’m sick of it. Gremlins I tell yeah have hi jacked my car. Could it possibly be something with the SCT chip and tune? I have no clue as I did what I could. So surely there is spark, fuel pressure, fuel, so what am I missing?? Any ways chime in and enjoy the pics!!
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idk if you guys watch iron resurrection but got to meet Shag from the show, he was standing behind me at the merch line and we got to chatting, super cool guy, their shop isn’t that far from my place and said to swing the car by for some photos just not during lunch!!
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