Up until now i've just chalked this up to her getting pissy now and then, but if it's something simple that i can fix, i'd like to take care of the annoyance. I'm thinking it may be a tuning issue.


Scenario:

Sitting, idling in the drive thru line at dunkin. Drove there fine, fuel press., oil press, temp and battery, and vacuum, are all good. Car's currently running on hess 93 octane with a little shell 93 octane left over.

After about 2 minutes in the same spot, the idle drops, and it stalls. Start it back up, runs for a little while, then stalls. So i say fuck it, i pull out of line and go inside.


Drive home, everything is all fine still, runs great, no stumbling missing or anything. Get home, sit in the driveway (also on a slight incline like the drive through line) idling for between 5 and 10 minutes, and no problem.


Not a huge deal, only happens while sitting at idle so its not like itll endanger me on the highway. Just a little annoying.

any ideas?

Fuel pump or filter?

fuel pump is a high volume unit, kicks on and runs dead linear without any interruption.

could be fuel filter, i hadn't thought about that. But wouldn't that cause some stumbling while driving and such?


Fuel pressure at idle is right around 30 lbs. Driving around it can fluctuate between 32-42lbs depending on how hard i jump on it.


I know its running rich already, haven't had the chance to get it tuned yet. But, i don't think it running rich is the problem.

My buddy had a similar problem and it was his pump, started ever so slightly sometimes and gradually just got worse.

hmm...again though fuel pressure was constant, i can hear the pump from inside the car and it never stumbled or anything.

fuel filter is only 10 bucks, anybody know the walbro part number for a 98 cobra? I'm only seeing 96-97 everywhere i look.

Be careful with walbro stuff... Not so good stuff anymore, buddy went through 4 pumps last year.

yeah, just dug around and actually cant even use a 255 on the 98 style tank, highest itll go is 190. Ford racing makes a drop in 170lph but i doubt that's enough for this car. In order to use the fuel pump i'd want (ford racing 255) i'd have to buy a 96-97 style gas tank because of the way the pump bucket is designed, unless this has already been done. Like i said it's a loud freakin pump haha you hear it first thing going into accessory, and you can hear it while the car's running.


I'm still not convinced its the pump though, i would have heard it cut or stumble or saw fuel pressure drop, no?