ok so about 3 weeks ago my blazer started crapping out, i assumed it was the fuel pump as it has been going out so i replaced it and the sending unit at the same time, same symptoms starts right up idles great nice and smooth, give it gas it revs right up hold it up in the rpm's and it stays right there smooth and sounding great, but the second you let off the gas it idles down correct and then just dies. after it dies it wont start till it wants to and again will do the exact same thing die when its revving back down.


i have replaced the fuel pump assembly strainer and all, made sure the ground wire is a solid ground by using a dremel with a wire wheel to sand all the crap off to bare metal and a good nice bolt. haven't done the fuel filter as it holds fuel pressure threw the whole ordeal 60 when you turn on the key doesn't drop below 54 even at high revs so i figured its OK. it will start with starter fluid and run till its gone, but it wont start without it.

oh yea my ecu was shot as it would mess up the iacv and cause it do idle and run wild so i got a new one, at the same time i also did the fuel pump relay

so after that i was thinking cpi unit or fpr well i did that in june of 09 it was under warranty so i got a new one replaced the whole cpi unit(in which auto-zone screwed up the first time and didn't charge me enough for the cpi unit and it cost me a extra 200 bucks i wasn't counting on spending), started great idled perfect revved up great held fine let off gas and bamm it dies and wont start....wtf...fuel pressure is fine whole time. ok so im like damn wtf could it be i checked the spark and it was orange and looked kinda weak so i replaced the coil as it was oe with 180k on it couldn't hurt right, got out the dmm and looked at wires coil wire was at 3 ohms and the rest where in the 4-9 range so i got new ones. got a new cap and rotor while i was there as it was worn and had a lifetime so i used it.

so ok i got new wires new cap and rotor, new coil should be a awesome spark get it all on and.....bamm starts right up rev it up and idle down and die....arghhhh!

so now roughly 350-400 bucks deep my blazer still wont run my ford is acting up just got outa the hospital for more cardiac problems and i dont know what to do next.. i need my blazer i miss her....any ideas thoughts donations of c4 or explosives with a good insurance agent i could use i have till weds and no more money...please help!!

thanks


update: it wont start now...fuel pressure is good has spark....



copied from another section hoping i get more help in this section.

 

You didn't mention anything about codes, are there any codes? From your sig it looks like this blazer is a 93?

 

no codes...and yes a 93 cpi


and now the oil pump looks like its out in my ford farm truck....so now i got no wheels...

 

I understand you can hold @ rpms but when the engine revs down it dies. Have you tied to use the starting fluid to keep it running as it revs down?

 

Try pulling the IAC and clean it up. It opens and closes based on throttle to allow enough air to maintain idle speed. Possibly closes when you bring RPMs up but does not respond fast enough to open when you let off.
Now it may be stuck shut since you cannot restart motor. I've used Brake Cleaner on mine but am not sure if it's good for it or not, so clean it with whatever at your discretion.

 

Those GM IACs do some nasty things when they go bad. I have cleaned many and replaced many on many Gm cars. The worst was a 92 lumina I had that would not start sometimes. I would pull the IAC and clean/ tap on it. Then start it up to hear the 3.1 loping like it had a huge cam. Then would maintain 70mph with the throttle completely shut. I had to power brake it to keep the car from dying at a stop. Got home replaced the IAC and it purred.

 

ok put a known working iacv on it, it started and ran then died, upon dieing i tried to crank it over to get it to start and no start so i continued for a 30 sec burst stopped, then ran to the number one plug pulled it out and...dry as a bone so i still got 58psi of fuel at the check valve but what if my wire harness to the cpi unit is bad.

if i knew what voltage the plug was spose to be putting out i could check it when its dead and see if i have voltage to the cpi plug and if i do i wonder if the end on the cpi unit itself is bad...now somewhere on here someone had a part number for the harness as the ones i find are the wrong one bt for the life of me i cant find the post thread or anything about it.. so if someone knows off hand that would be great..

or if my train of thought is wrong input is also good

 

see if this helps....

http://www.tomorrowstechnician.com/A...injection.aspx

 

Is there an injector fuse similar to TBI, or are all injectors run of the same fuse for the whole electrical system?

 

ok im so confused about fuel pressure one place says 66 one says 60 one says 58....so what should it be when i turn the key on and what should it drop to for starting..

update:
tonight i put on a new cpi harness pigtail from bwd am getting 12.6 volts on the red wire and not sure about the blue as i didnt have any help and dont understand if it should pulse 12 volts or what