91 camaro rs tbi 305 auto vert stock except edelbrock cat back and open element. Hmm car randomly started acting up idle goes way down and back up by itself until at running temp. Runs like poop when cold and only a little better when warm but idles great when warm in park or neutral randomly cuts out in gear and sputters and jerks. No vacuum leaks. Only code I got was 34 map sensor so I just threw a lil money at it and replaced aging sensors iac, map, coolant, also fuel filter coil distributor cap n rotor, plugs wires, egr valve, vacuum hoses. Helped a lil bit for a week or so now car getting progressively worse so I'm guessing fuel pump issue? I just stuck an inline fuel pressure gauge on it it's at 9 psi cold start and goes down if I tap the throttle I don't have much to diagnose it and I'm no mechanic but can do basic things and I live in a townhouse complex can't do much in this parking lot lol. I'll prob take it to the shop but hoping for more input thanks! I did attempt to post a link to an idle video hope it works and helps thanks! Ps in video I am not touching throttle that's the car "idling" lol

http://s1279.photobucket.com/user/w_patrick79/media/Mobile%20Uploads/trimC4D3F1A7-438E-446A-96D6-5EA11064C457_zps3bab5140.mp4.html

 

9 psi at idle is the LEAST amount it can run on. Tapping the throttle shouldn't drop the PSI. That effectively means that under throttle, the car doesn't get enough fuel. What does it go down to?

 

Just started it again even lower at 7 psi goes down to 6 when tapping throttle and then cuts out also fuel pump priming I can hear it but takes longer to start everyday

 

Fuel pump is shot. Drop tank and replace. Consider TPI pump while you are there

 

Hey thanks for the info man just needed a second opinion greatly appreciated

 

 

If you measured fuel pressure, with a good gauge, and you only see 6 to 7 PSI then it is time drop and replace. It is very common in GM cars to start loosing in tank pumps after 20+ years. If you're getting 6 to 7 PSI you probably have a fuel leak in the hose between pump and feed through assembly. Leaks will kill FP after time - it spins faster and wears itself out.

When you do the R&R make sure to use SAE 30R10 submersible rated fuel hose between FP outlet and feed-through. For best results use AC-Delco FP pump kits - with correct grade hose. If you get a 'white box' kit toss FP hose into a garbage can and get the right hose from Napa or another reputable store!

//RF

 

Wow great info will do I love you guys lol thanks