i have an 89 chev blazer, 4.3 2wd and after a couple few minute of running it will sputter in and out and die. sometimes i can keep it running (sputtering) if i feather the gas pedal but it still ends up just dying. it seems to start right back up but sputters and dies. if i let it sit and come back to it sometime later, itll start up and run fine again for a few miles then same story. when it first started happening to me i was able to go about ten minutes before it started, now im lucky if it will go four or five minutes before acting up and dying. i changed the fuel filter. no difference. a friend of mine hooked it up to his snap on scanner and after punching in the cars info it said something about fuel system relay and ecm limp home mode. i forgot to mention that each time it starts to act up it will blink the check engine light on and off, pretty much in sync with the sputtering. sometimes the check engine light doesnt blink in sync, it just stays on. thats only for a few seconds and it is usually back to blinking with the sputtering. at least thats what it seems like. while my friend was playing with the snap on scanner he at some point diconnected the battery to clean the brain. on my test ride it of course did what it does and threw up the check engine light again, sputtering and all. yesterday i went to shucks and they put it on their very basic little scanner thing and it said nothing at all. no codes stored i think it said. however, since clearing the brain it did throw up the c.e.l. and acted up. i would think it should have been logged then, huh? anyway, i bought two different kinds of relays for the 89 blazer, a small grey 4 pin one and just to cover bases also a larger 5 pin one. im not finding my fuel pump relay anywhere in the engine compartment because i dont know where to look or even seeing something id guess was it. there are two relays installed on the engine wall fender driver side and they are right next to each other. i dont even know if it is the relay or egr (?) or what that is giving me the problem. please help

 

Those are the relays. I THINK the left one is the relay. Im not sure what the other one is for. If you want,just swap the 2 used relays and see if anything changes with the fuel system. Honestly it sounds like the pump is going out. if it is buy only the ac delco or delphi. I purchased the carter/airtex and replaced them many times within a few months.

 

chris, thanks for your input. my friend did switch the relays on the fender wall and it still did what it does. this afternoon, about an hour ago, i myself switched them and let it run for about ten minutes, at which point it started sputtering and wanting to die unless i feathered the gas pedal. i even went ahead and unplugged both those same relays and it still started and ran as long as it seems i wanted it to although sputtering and wanting to die every other minute or two. inbetween those little periods it would run normal it seemed. rpms would pick up a bit and it would smooth out for a few seconds. like 30 or 40 sec then back to the sputtering. everytime it does this the check eng light flickers in and out . i even unplugged the vac line from the egr and no difference. you really think its the f pump? im so freakin broke now its not like im able to buy one and hope it fixes it, ya know... thanks for your interest man

 

honestly, my knowledge regarding cars/trucks is so limited its as if i was trying to teach french (i dont speak french) i do however grasp concepts easily and usually a quick study. at least the basics. if anyone can spare the time to offer their opinions and/or expertise, id be so appreciative. thanks in advance

 

Well, 1st thing you need to do is check the fuel pressure. Should be 10-13 psi. if its low its time for a pump. You need a fuel pressure gauge and a adapter for the tbi. Ask a salesman they should know what you need. I think you can "borrow" a fuel pressure tester at autozone,you just pay like $75 to use it and when you bring it back you get a FULL refund.


Second thing id check, remove the air filter housing and look at the injectors. Have someone start it and watch the spray pattern. Is it a clean cone mist or a drippy messy shape?


Another that can affect the idle if fuel is fine is the Idle air control. Its a round sensor thats plugged into the throttle body on passenger side. Unplug the square wire and remove the sensor and clean up the tiny piston and reinstall it.

 

We would like to know what the engine code that being set off is, use the paperclip method to check what code its tossing at ya, and let us know.

 

bend the clip into a U shape and stick it into the the a and b pins on your diagnostic plug. that's the plug under your dash/steering wheel, a little to the left of your center console. i believe a and b are the two pins in the upper right hand corner of the plug. then turn your ignition to on, wait till the first code flashes three times which will be a 12. the service engine light will flash the codes...So the 12 will be a
"flash"...then "flash flash" (1-2=12) thats saying the computer is reading and allowing the thing to read codes. after it flashes 12 3 times,IF there is any codes stored it'll flash the code. After codes are flashed it will flash 12 3 times again to complete cycle..


Ok i typed a bunch,im getting some breakfast. let us know how it goes.

 

thanks for the direction. im glad to have the paper clip method explained to me. im going to try it now and ill get right back here and post my findings. im thankful for all the help. back in a few.

 

after the paper clip method i had 32, 34, 51 flashed at me. (each was repeated three times before going onto the next code, i assume it was just giving each one in triplicate) in any case what i got from it was 32,34,51. lol, without you guys on this forum, i cant do alot with this info. lol thank you in advance.

 

GM Check Engine light Codes without a Scan Tool here ya go...