popping wows

[chicinwang]

ok i know the norm for tech questions or any other for that matter....but i'm impatient i've been looking and have not found an answer.....so here goes....87 bronco xlt 5.8 auto new wires,plugs cap,rotor,chain and gears,pickup in the dist...oops dizzy has been replaced module checked(at a parts store)tps,map,coolant temp,idle air,are all with in specs..the prob is it's hard to start idles fair but try and give it the fuel it spits and pops in park or drive....when the key is turned on the pump runs constantlyand coil is firing..oh and it has 40lbs of fuel press w/key on and trying to start it but looses it very qwick when the swicth is keyed off..and the fp relay is good....what gives

 

[Miss Kitten]

maybe some bad gas or there's some water in it?

 

[Bronc76]

this may not be it, but have you changed fuel filter?

 

[chicinwang]

yep previous owner replacedit... i removed and checked it for SAG..and it flowed great fuel looked great as much as i can tell....but i have found somethin ouy... i got to thinking that i had a code reader so i pluged it in the sap sucker went HAYWIRE (the reader)buzzing and beeping all crazy so i replaced the batt same thing so i tried it on my dads 93 pu...worked like a charm.....beeped out the codes like it should???? so i started leaning toward the ECM so i removed it...and i found out that it was a F0T on the ECM F^%$ thats a 1990 ECM...so i loked at thee vin the sapsucker originally came w/ a 302 notta 351 aaaaarrrrrrgggghhhh...i always get the ***** ones....ECM will be in in the morn..please if anyone comes up w/anything dont hesitate to let me know cause that may not be the prob...thanks for the replies!!!!!!

 

[fordsohc46]

it should hold fuel pressure after key is turned off. i think the leak down spec is something like 5psi in 10min. if it is leaking down i would clamp the return hose with vise grips or find a way to block it and see if it will hold pressure with key off. if not the problem is in the pump. this can cause a hard start/long crank issue for sure and could cause a running problem.

 

[chicinwang]

yep it was the ECM plugged in the new one...and it fiered right up...drove it round bout 03-45 min oil pressure dropped and the left front whell started shimming bad!!! so know gotta pull the pan and check the pickup tube.....**** i might as well gohead and replce it after going thru all that....thanks for the replies i"ll keep ya posted...