Missing w/ strange noises from fuel pump

[platoribs]

Hello fellow SHOwners, I've got a 93 mtx with 145K with a new OE fuel pump 40K ago. Occasionally (2-4) times over the past few months I've had this strange start-up condition.

When the fuel pump spools up before cranking it makes a very unusual noise, hard to describe without misleading, suffice it to say it does not sound like normal, it's louder and not the consistant spin like noise I'm used to hearing. Then when I crank it it will start up but there seems like there is a miss or something preventing it from idling up like normal. The tach reads a rough 500 RPM and seems like it wants to die. At this point I'll give it a little peddle and it will slowly rev up and then the problem seems to go away. It just did this again at lunch a few minutes ago while I was lunching with Mike from Midwest SHO. He hasen't ever seen anything like it. After a minute I shut it off and restarted it and it started normally.

Would you guys please offer suggestions as to how to diagnose this so I don't end up blowing a lot of $ fixing unrelated stuff.

 

[revhardSHO]

Sounds like a fuel pressure issue. Even though its a low mileage pump Im betting thats your problem.

 

[platoribs]

Sounds like a fuel pressure issue. Even though its a low mileage pump Im betting thats your problem.

It's getting reinforced motor mounts, strut mounts, swaybar bushings and endlinks, and ASFB in the next few weeks.

I'd really like to get more opinions or confirmations of this before I start these other projects so I can address it all at once. Thanks smithsil, anyone else?

Would low fuel pressure cause the missing?

 

[bgjohnson]

low or inconsistent pressure would cause it to run like crap or chuggle. you could have a bad connection, i had a friend that the pump would do that and somtimes it wouldn't even run, so first off i'd check the connection

 

[Dr.Evil]

my friends car is doing th exact same thing. It sounds like the fuel pump is blowing air into the tank...? I can hear is spin and it sounds normal, except for the gurggling sound. it also will not idle or rev. After cycling it about 10 times, it fired up fine and sounded fine (both motor and pump). If anyone knows what this is please post it...I don't want to change thte pump if that is not the problem.

 

[91whiteshoplus]

i bought a fuel pressure meter for about 25 bucks from pep boys to diagnose my pump. it goes onto the schrader valve on the fuel rails.