Ok so here we go,

2002 Blazer ZR2 right under 90K

Spark at the plugs,
Fuel pump wines when key is turned on,
Fuel pressure when cranking is around 40
After cranking stabilizes at about 35, then quickly drops to 0.
Pulled intake tuke, disconnected the MAF, poured some fuel into the throttle body, and she started momentarily.

I read some where on here that it may be the fuel pressure regulator.

Any help would be great.

Joel

 

If it drops that quick youve got a problem. Also you need around 58-62 psi to start.

The quick pressure drop sounds like FPR, but the low pressure at crank sounds like fuel pump.

 

Change your fuel filter first... MUCH cheaper and easier fix if it works.

 

betcha it'll be a pump-use an AC Delco but....try to iso the problem area...possibly take a pressure reading where the fuel filter is with the front line unhooked to iso it to the rear.(or front).JP ps good luck and open your checkbook![&:]

 

Ok so how do I isolate to ensure that it is rhe regulator or the pump. Help would be great, need this thing running.

Joel

 

If its the FPR, you wont hold fuel pressure...which means to isolate it, you need a fuel pressure test.

 

Get a fuel pressure gauge and a buddy. Put the fuel pressure gauge on it. Key it on while your bud(or yourself) is underneath and takes needle nose pliers/needle nose vise grips(my favorite) and pinches off the fuel line from the tank-the feed line-the fuel filter line. This has to be done immediately after the pump completes its two second cycle. If pressure holds-issue in tank. If it bleeds-in the intake. good luck! JP[:@]

 

Is the fuel pressure regulator some thing that I can remove and clean out and put it back on and it might work? or is it either good or bad?

Joel

 

I've never cleaned one but just bought one today for stock...ACDelco-list about $100(just under-check Rock Auto a fav. of posters on this site) but...if this is what you think the problem is you can remove the upper intake plenum and re-hook up the fuel lines, key on the truck and watch the regulator. I did a 96 last Friday with a bad FPR and this technique worked slick. Upon keying the Blazer on I could see a 'teardrop' of gas drip out of the FPR along with fuel pressure bleed off. Never heard of cleaning one up-maybe someone out there has but...if you troubleshoot it to this point and the FPR is the issue, I would be putting in a new ACDelco-I prefer doing things once! JP(PS-somethings)[X(]

 

A fuel pressure regulator has a diaphragm inside. If it is leaking, that means that the diaphragm has a tear in it. You cannot clean an FPR that is leaking. If it is the o-ring seal, then you may be able to replace that, but as JP states, this is a job you want to do once. IMO the work required to get down there is worth a lot more than the part.

Anyone attempting to diagnose a fuel system problem on any one of the 96+ SCFI or mid-2002+ MFI motors should have a look at the DIY section for a complete diagnostic chart on the fuel pressure test procedure.