I have a 95 blazer 4.3 vortec, cmfi, edI. My fuel pressure is 60psi and I have spark (I used a test light pooked into the rubber spark plug boot) I went to test my fuel injectors by testing for power and the pulses using a test light(I dissconnected the wirering harness that go's to the injecters) I got a steady light on one wire and nothing on the other. So I was unplugging other sensors to see if I could get a pulse and then I got no power at all going though the one wire so I plugged every thing in and it started right up and ran great for 5 min. Then just shut off, I checked my wire and it had power I tryed starting it a few times and my power went off in the wire agine so I plugged it in and it started right up and died after 3 or 4 seconds I can repeat this over and over aging. Im confussed now. Oh my problem was it felt like it was running out of fuel so I pulled over and it died so I towed it home and started checking thing out.
You got me confused here-Do you have a TBI or the CPI-spider assy?
December, 26, 2011 AT 10:53 PM
Its a central multiport fuel injection according to the picture in the book. It does connected to OBII even though its a 95. Im learning as I go so if I dont know what Im talking about Id say TBI, but the picture in the book looks just like my motor (its the only one with the Vortex plenum on the top) and calls it cmfi. That wire I was talking about its supose to be the injector harness(wireing) that goes to the injectors witch I cant get to unless I take the air intake plenum off according to the book. Thank you soooo much for any advise or point me in the right direction I dont know what I should check.
December, 26, 2011 AT 11:21 PM
The engine light was on but shut off when it started to die and hasent been on since. The last time I checked why it was on it was the o2 sensor it came on and off with the same code for the past few years so I never thought twice about it. Also I replaced my spark plugs and fuel filter about a week before this happened not that its relivent or not just trying to give as much info as possable, thank you
December, 26, 2011 AT 11:58 PM
Do a KOEO fuel pressure check and monitor the fuel pressure how long it'll drop to zero-
December, 27, 2011 AT 12:02 AM
I dont know what KOEO means but I can check the fuel pressure again
December, 27, 2011 AT 12:11 AM
Key On Engine Off
December, 27, 2011 AT 12:13 AM
KOEO = Key on, engine off
You can't test injectors using an incandescent test light. That will take your computer out pretty quick. You have to use a noid light or something with an LED.
December, 27, 2011 AT 12:29 AM
Ok thanks I didnt know that, I did buy a box of noid lights but I didnt use them yet I was hoping to take them back since they where so expensive but I can put one on it if you want. The book said I should measure the resistance on the injector side but I thought the test light would show me it was working too oh well the book can be confusing it has multipal systems it talks about anyway the pressure test it still going on its been 10min. And its only dropped to 50psi it was a hair under 60psi when I looked first. Thank you
December, 27, 2011 AT 12:50 AM
48psi after 35 min, by waiting longer what will this tell us? Thank you.
January, 27, 2012 AT 7:13 AM
Nothing. 35 minutes is more than plenty. It isn't the fuel pump. You need to check the injectors to see if they're being pulsed.