I watched my lead tech diagnose a fuel pump issue yesterday with a snap throttle test on an older F150. Pressure was fine at idle but would drop way down after a snap throttle. He started with the filter and no change and then did the fuel pump and got it running fine and shipped it.
I plan to go to this car tonight and diagnose it. Let's hear which tools and methods ypu guys would bring.
other info is plugs are on the blacker side.
Oh yeah my car was running like turd before when my in tank failed and put extra stress onto the in line. I replaced my in tank and got it working but the damage was already done. In line fuel pump would make a oscillating whine and car would run sluggish as heck(massive hesitation). Contrary to popular belief fuel pumps can "start" failing, it is not a back or white thing but can be in between too.
I also had to fix my radio suppression relay which I found that my mechanic was lazy as heck and just silicon glued the wires to the pins. I even had to replace my maf because there was a LH 2.2 maf in my LH 2.4 car lololol!!! Also replaced my fuel pump relay and crank position sensor for good measure. I did compression test, replaced fuel filter, and a hours worth of fixing to get the car where it is now. Just do your usual visual checks and you'll probably find the problem. Also many of my problems were found via codes, what does the obd1 system say? Mine in the past said "fuel injectors" which after I took them out was absolutely falling Apart. Once I replaced this, codes went away and car drove waaaaay better. Then it said maf code which after I put a normal lh2.4 in there ran evveeeen better. So basically don't underestimate obd1, it actually told me accurately what was wrong. Same with the fuel trim code. Replaced fuel pump and fpr and stuff and had good adequate pressure to the injectors.
I think I had a total of 5 codes. 4 of them I fixed. Last one I couldn't fix was crank position sensor, which was bull crap.... so I replaced my 563 ecu with a 937, and behold no codes
and a amazing running car! It actually cranks too fast, literally .5 seconds of cranking before it fires up lol. And it's fast! I raced a BMW i3 SUV with 220bhp so I at least have that
!
And let me tell u guys....never run a 2.2 maf in a 2.4 car, you should've seen how it ran lolololol! Well it wouldn't hold idle after unplugging the battery and during the relearn phase. It would die and I would have to start it up again to let it try and relearn idle, die for another 5 cranks until it figured out how to idle with the 2.2 Maf. Would have to also hold down the gas to keep it from dying. Once it learned idle though you were pretty much home free, however God save you if you removed the battery terminals.
Fumomike~ master Volvo tech