Sounds like the pump is good, could be the spider or regulator

 

I changed the spider to the new MFI upgrade, a Standard Motor Products FJ503.

 

Leme get this straight Key on, engine off, and with the fuel pump running, (first 2 seconds after you turn the key to RUN) pressure is 60+psi and holds at 58psi for 10 minutes. If that's correct, the fuel delivery system is working fine, (pump, lines, regulator and injectors). Clarify something for me here, does the fuel pressure drop and then it stalls, or does it stall and then the fuel pressure drops? Next, (and I'll get flack on this one) with the engine at operating temp, what is the fuel pressure when the engine is at idle?

 

It is happening simultaneously, so, the fuel pressure drops (usually when I hit the accelerator, but not always), it tries to recover, but can't and then it stalls. But I have got it to hold idle and fuel pressure holds.

I'll have to check again about the idle operating fuel pressure, but I believe it is always between 55-58 psi with engine running at op. temp at idle.

 

When you start the engine, does the check engine light come on, and then shut off? If it stays on, or flashes, what DTC's are in memory?

 

I'd check, but I don't have a scan tool. Can you recommend one that is affordable but will do the job?

 

Sorry to jump in, just waiting for animal control to come. Need to find out if a dead raccoon that came in my cat door is rabid ( came in semi-alive ).


Any of the cheap scanners you find at a local place will do to read codes.


A bi-directional that will actually allow you to get into your cars computer and order it to do things are very expensive.


Research the Actrons . The only thing I would recommend is that it shows live data and has storage.


Anything more then $75 is a waste. The reason I say that is unless you spend 3G's it's just bell's and whistles.

 

Autoenginuity seems like a good tool. I was going to go ahead and get it, esp. for my Ford powerstroke 7.3L diesel.

Anyhow, I finally (after bitter cold and snowstorms) got to work again on this Blazer. I found out for one thing that my alternator had gone bad in the midst of all this and had ruined my battery to boot. So I replaced both and NOW everything is back to square 1 when I drove back from my mom's (about 600 miles) and it started misfiring real bad. I got a scanner and its reading P0300 multiple random misfire which, DUH, it's doing.

So, not quite sure where to go from here. I had replaced all of my ignition parts. I can check all the plug wires to make sure their tight Can a bad O2 sensor cause this? Or maybe a collapsed catalytic converter?

 

When the engine is at idle, trans in neutral or park, momentarily open the throttle quickly about half way, then back to idle. Fuel pressure should increase, then drop back when you close the throttle. Try that and post your results.

Next, on your scan tool, go to the codes menu and bring up "freeze frame data". It is a "snapshot" of all of the data when the P0300 was set. Post all of the readings.

 

Ok, fuel pressure was zero this morning. Added some fuel from a can, it jumped up to 60 psi. Guess a little ice got stuck down there. ??? Anyhow, here is the data you asked for:

Cleared DTC's, started over:

Started with P0301 and no FF data then, scanned again and got P0300.
FF data:
Fuel Sys 1: CL
Fuel Sys 2: CL
Calc Load: 3.1
ECT: 188.6
STFT B1: -2.3
LTFT B1: 8.6
STFT B2: -14.8
LTFT B2 3.9
MAP 8.9
RPM 1044
Speed 0
MAF 1