Video ?

I did static pressure leakdown test on another car (before $700 for 16 new INJ's)...

The same in principle.

 

My 1999 Blazer ZR2 have been behaving strange

Early this winter i was going to use the car and when i turned the key to start the car the starter operated as normal but the car did not start,

I thought that the fuel pump was bad so before i was going to test the fuel pressure i turned the ignition on and used a cut off q tip that i inserted into the fuel pressure valve thinking that if the fuel pump is okay the the fuel will flush out as long as i keep the q tip pressed in, But no there only came a little squirt of fuel and that was it.

Since this was winter i did not bother working on the car outside and since i have several cars i did not have a look at the car before earlier this spring
The first thing i did was goinf thru some cable connectors and i also charged the battery.
Then i thought i should try to start the car and the car started right up at once. Not any problem at all.

I have used the car for a litlle over a month and one morning a week ago the car behaved just like it did erlier this winter and would not start.
I checked the fuel pressure and there was only the same little squirt of fuel that camme out of the test valve.

I thought that the fuel filter must be clogged so i changed that a couple of days ago and after i took the old filter off i could easy blow thru it so the fuel filter looked fine but i replaced it with the new fuel filteranyway.
I also cleaned a lot of electric connectors using electro cleans. This included the 4 connectors that goes to the ECU

After i had done this i tried to start the car with not much hope that the car would start but the car started right away

But i find it strange that the car have behaved this way and when the car will not start there have been no fuel pressure. I still have the same fuel pump that was in the car when i bought it.
All i can say about the fuel pump is that the previous owner replaced the fuel pump late in 2012

 

An Amazon based solution for the hook up to the fuel filter output:

 

What is the allowable pressure drop across the injectors? I cannot find a spec on this. I tested mine with a snap on scanner and had about 10 psi drop after each one tested. trying to establish if that is acceptable or not.
thanks

 

Your a lifesaver Captain Hook! save worthy sticky for a common troubleshoot on these 4.3s!!!

 

A common "injector balance test" is to apply the same injector pulse scheme to all injectors one by one after energizing the pump/fuel rail to the same starting pressure then measure the pressure of each injector after the opening pulses and consider the results good if they are all within 1 or 2 PSI of each other. Make sure to also do a leak down test of the whole system by charging the lines with the pump and make sure you are still at least 55psi after 5 minutes.

George

 

Fuel leakdown test results... Engine side of filter 86 initial and 68 after 10 mins.
At test port 60 initial, as soon as pump shuts off drop to 52 and after 10 mins it's at 44.
Fuel pump replaced last year 4 months b4 spun bearings.
Upgraded, brand new spider never used till now.

98 Blazer 4.3 4x4 4 Dr vin W. Rebuilt motor never started. Fuel in oil, noticed smell while priming oil pump, checking oil pressure. Zero pressure on instrument gauge, blowing out past new o ring and gasket (from dealership) on remote lines adapter...all 3 bypass valves replaced with no change...3 gallons of oil wasted...anyways...

Any help greatly appreciated.

Jim

 

https://m.harborfreight.com/fuel-injection-pump-tester-62623.html

Will this one work?

 

Sure will Lewin; GREAT price too.

 

q[left]So this is the 3rd fuel pump getting put in. I was ready to do it last night but part did not arrive and after finding this fantastic and informative site, I tested the fuel pump out of course and it fired up every turn of the key. In my new found glory I canceled the late amazon order and proceeded to put my rig back together. Starting right up I cleaned up and the next day fired right up again. A few hours later I took it for a quick spin approximately 1 mile there turned it off and 10min later started right back up however on the ride back a block from home, ty, ty ,ty. It lost most power and felt like it was starved. Got a quick boost and had to coast down my street into driveway. Next morning it fired up ran for 10 min and died. It seems as though there is intermittent power to the relay fuse box. Also I’ve had to hit the tank just about every time to get pump to kick on. I’m going to change out pump again because pressure only got to 55, it held on bleed down! Combined with the need to bang start the pump. Any suggestions on loss of power to relay box?!