Fuel Pressure Issues!!

[gmcturbo]

in an attempt to find my stalling/rough idle problem today i checked my fuel pressure. Base fuel pressure was jumping between 53-52 PSI really fast. Vaccume line on it was at 48-49 PSI also fluttering very fast between the two. The fluttering is just like my tach flutter and sometimes it will put out some white smoke idling (rich). I've heard that 42PSI is stock base PSI. My truck is completely stock with a new MAP sensor, coil, conrad cap and rotor, cheap wires (soon to be changed), cr42ts's, k+n in box filter, fuel filter, no vaccume leaks, and fresh oil change. I have severe tach flutter and sometimes there's a quick intermittant (random) miss like a wires arching out occasionally but not all the time. It also stalls alot when first put into gear (like backing out of my driveway). Any help?? I want to fix ASAP...

Thanks-
Mike

93 ty #0731
black/grey - stock

 

[lSyclonel]

check to see if your regulator is leaking on the vacum side

 

[gmcturbo]

how exactly make sure the bolts are tight and that it's seated properly?

 

[ItsMyTy]

Base fuel pressure was jumping between 53-52 PSI really fast. Vaccume line on it was at 48-49 PSI also fluttering very fast between the two.

I wouldnt worry about the flutter on the gauge.. you're gonna get that with some setups. You need to find out why your pressure is so high. Is it an adjustable regulator? (screw on top). If so, adjust it back down to stock pressure. If it's the stock non-adjustable regulator, check your fuel return line for kinks (like above the transmission, etc). If that checks out ok, you're gonna need a new regulator.

white smoke idling (rich).

rich is usually black smoke, oil a bluish white

I have severe tach flutter and sometimes there's a quick intermittant (random) miss like a wires arching out occasionally but not all the time.

you probably answered your own question "cheap wires (soon to be changed), "

 

[gmcturbo]

thanks for the helpful info itsmyty. i didnt think about the return line. the FP is high right?? all the mechanics at work think its about right off the top of their heads - although most have never seen a ty or sy...

ill do the wires this weekend and i might as well buy a AFPR for future mods.

mike

93 ty #731

 

[Phoon30]

thanks for the helpful info itsmyty. i didnt think about the return line. the FP is high right?? all the mechanics at work think its about right off the top of their heads - although most have never seen a ty or sy...

ill do the wires this weekend and i might as well buy a AFPR for future mods.

mike

93 ty #731

On a relatively stock truck like yours, fuel pressure should be around 45 at idle with the vaccum line disconected from the fuel pressure regulator and plugged up . If you don't have an adj. fuel pressure regulator, you should get one. Also get a new fuel pump. Those are two of the first mods any new syty owner should do if thier truck doesn't already have it.