5.0 Woes

[chrisfletcher]

Hey guys,

Ive recently ran into two different problems with my 5.0.

It is a 4cylinder car, with a Mass-air 302 conversion. Ive been having the issue that maybe twice a week out of the blue, ill try to start the car, and it'll crank really slow, as if the battery is low on voltage. When i let off the key, the solenoid stays energized and continues to crank the car, regardless of key position (or if the key is out all together). The clutch safety switch has been bypassed also. I have replaced the solenoid, but that was to no avail.

Also, this past weekend i swapped on a set of ported boss 302 heads with crane roller rockers. Fired the car up (after realizing i had ignition timing 180 out ) And the car will not 'learn' itself to idle. It revs freely, and smoothly, much moreso than before with the stock heads. Ive checked for airleaks, and came up with nothing. The car will rarely idle, and when it does, it is sparatic, basing out at around 500rpm. Driving the car resulted in a much better 4500-rev limiter pull, with a slightly less agressive idle-3000rpm pull.

The only thing i couldnt recall, was if there was a vaccuum line on the fuel pressure regulator or not. I tried it both ways, and came up with nothing.

Any thoughts or ideas would be greatly appreciated. Thanks guys.
Chris

 

[86bluecobra]

This should be in Tech.

If it is a stock fuel pressure regulator then yes there should be a vaccuum line on it.

So when you talk about the car not learning have you removed the battery cables and let it sit for a while then reinstalled?

If it isn't Idling or it is surging go through Jrichker's sticky.

 

[85ragtop]

Moved to tech.

 

[chrisfletcher]

thanks...

Ive snooped around the site, and havent really came up with much.

My newest issue (after letting the car sit for 24+ hrs with the battery unplugged), is that the car idles worse than ever, (sometimes at 1500, sometimes at 500, sometimes jumping around), and now backfires like a mofo every time u come from 4000rpm or greater, and let it come down, then step on it again, according to a car following me, was literally shooting flames.

It burps and hiccups its way to 2500rpm, and then seems to be okay, but low on power, and below that it just runs terrible, jerky, and stutters.

 

[MahFiVeOh]

Hey guys,

Ive recently ran into two different problems with my 5.0.

It is a 4cylinder car, with a Mass-air 302 conversion. Ive been having the issue that maybe twice a week out of the blue, ill try to start the car, and it'll crank really slow, as if the battery is low on voltage. When i let off the key, the solenoid stays energized and continues to crank the car, regardless of key position (or if the key is out all together). The clutch safety switch has been bypassed also. I have replaced the solenoid, but that was to no avail.

I had this problem also.After replacing the solenoid several times my mechanic suggested using a different solenoid.We ended up putting in a solenoid from a 1981 Ford E150 van with the 302.The solenoid is almost identical to the one that was in there, the only difference was the shape but it didnt affect instalation.Its been almost 2 years and i havent had a problem since.

Just figured i'd give you the solution that worked for me

PS The part # is 84017 and is from CarQuest.

Good luck.

 

[chrisfletcher]

thanks ill give it a shot... Its a little embarassing to have the thing freak out and me running around it like a banshee trying to get the hood opened fast enough to tap the solenoid.

Got the car to idle, but it still seems to have a slight off-idle hesitation, and pops under off-throttle decceleration, and occasional slight pop/backfire as soon as the throttle is touched.

EDIT: And i cant seem to find my self-test port...its nowhere to be found on the firewall near the passenger side strut tower.... any ideas where else it may be

 

[MahFiVeOh]

thanks ill give it a shot... Its a little embarassing to have the thing freak out and me running around it like a banshee trying to get the hood opened fast enough to tap the solenoid.

Yep......been there done that.I had an adjustable wrench in my glove box for that or to remove the battery terminal if that didnt work.

 

[chrisfletcher]

hah..... at least im not the only chump thats been in this position... To make it even better, since ive bought the car the hood release latch has been broken off (the T handle has no ears left, so its just a straight piece), and every time it happens, u either need super human strength to pop it, or hurry up and find a pair of pliars.