Goosepoop302

I'm having an issue with a hesitation or sporadic buck. Occurs under acceleration but only every once and a while. Only once did the check engine light come on but immediately turned off. I am suspecting my fuel pump currently as my fuel pressure will sometimes bleed off very fast as soon as the car is turned off, other times it will hold for some time. The car runs and drives great for 20min or more without issue then occasionally there is a power loss or hesitation while accelerating. FPR is new, pump currently is a 255 walbro that was installed years ago..

Can a bad or failing pump cause issues like this?

any other ideas on what to look at?

thanks for your help!

TrimDrip

Why don't u pull the codes to see if it stored anything. With the light coming on like that it could be the maf as well.

89StangGTConvertible

Yeah, pull codes... I bet something got stored. Sounds fuel pump related to me, though...

malo012000

Maybe plug wires

Goosepoop302

well I stopped at oreilly auto to pull codes, no luck. I tried both the engine bay port and the connection under the dash. Neither one would connect to the vehicle although while it was trying to connect the rpms were sitting around 1400 then 1200 like a test was being done.

In hopes it was a fuel pump issue I have dropped the tank. I found the in tank filter looks pretty gunked up and the small rubber piece on the pump hanger is ripped and falling apart... what is this orange piece on the hanger called? purpose? I am hoping I can locate one tomorrow so I can reassemble.

I also pulled spark plugs today. they all look pretty good, maybe a tad white but nothing seemed to outta line. I want to run new lines from the top of my tank to the filter/ hardlines. what size high pressure line should I get?

any more help or ideas would be great. I was told that the diagnostic port was connected to the cig lighter fuse or something? if so where is that damn thing...

Goosepoop302

Doubt its plug wires, there pretty fresh and I have checked them over fairly recently

malo012000

Mine look good to then I put some water on them and ark city. does your tac jump when you push hard on the gas. By jump I mean seem like it studers?

Goosepoop302

97% of the time the car runs and drives great, no issues. I noticed when parking slightly nose down it did not idle at start and seemed to be running oddly for a minute or 2 then it was fine, also rarely while cruising at 3k rpm in third and a relatively small push on the gas can cause the bucking. TPS is new as well

TrimDrip

Mine won't connect to a scanner most of the time either. If I jump it with a wire it works though...

Lee Kelsoe

why did you ask about the tach jumping? just asking because mine was doing it when mine would start hesitating at WOT... I changed the plugs, wires, cap & rotor, and coil... the tach jumping went away, but the hesitation did not.... mine will start up fine, idle great, and accelerate awesome, for about 10 minutes, then hesitation, bucking, and bouncing idle... but in experimenting with it, found that it can be doing allt these things at its worst, and while still rolling down the highway, I can shut the ignition off for maybe 3-5 seconds and restart, and it will run amazing again for another 5 minutes or so then right back to horrible again...I've cleaned everything, new fuel filter, smog bypass with all hoses and vac lines sealed.... what can make it run so bad and then "reset" with just a 3-5 second ignition off on scenario?

don't meant to highjack your post... just wanted to get this in were there are people taking about it as well...