i have a '93 s10 blazer with 4.3L vortech. not running will crank but not start keeps backfiring. i have replaced distributor cap and rotor, fuel injectors, fuel pump and fuel filter and cleaned the intake manifold. still nothing. thinking of totally rebuilding engine since it probably needs it anyway.

i have read on here about people swapping for a 4.3L tbi, but wondering if the engine can be converted to tbi. asking because my brother in law just converted his suburban from fuel injection to carb and wondered how difficult it would be to do that or to tbi. i know i would be loosing hp once its all done but since its not running i got no hp anyway.

if it is possible to convert to tbi, i would appreciate some advice on how to go about and what i would need.

 

you could,you have to swap wire harnesses over etc. Problem is do you have the 4l60e transmission,if so your computer could be a problem since it runs off of it.

Also,the balance shaft on the cpi,will sometimes rub against the intake manifold. you can either grind it down a little,or remove it completely and replace the holes with freeze plugs. If you have the electronic 4l60 i dont think it'll be worth the time and effort. look in your glove box if you arent sure. Youll see a sticker with a bunch of codes. mool for md8 or m30. If its m30 you have the 4l60e,if its md8 you have the 700r4.


What brand pump did you install? these blazers like nothing but ac delco and delphi. Also,have you tried replacing the fuel relay? Do a fuel pressure test. It must hit at least 60psi and hold above 55 for 10 minutes. If it leaks down quickly its either the pump,or the injectors. They pressure kit comes with a adapter that you can use to plum into the fuel filter. Do the test there first and see if it holds,if it does. cool that rules out the pump.

 

it keeps backfiring, is the firing order correct? There is a way to use the existing wiring harness to go from the cpi to a tbi setup, I found it on some astro van site. they went from 4.3 cpi to a 350 tbi.

 

thanks for the replies. sorry that i didnt reply sooner. i ended up having my cousin take a look at it and the firing order was not right, guess i messed it up when i did it. he got it running and there was fuel in the oil cause the fuel lines in the plenum where cracked. after he fixed that, one of the rods was bad and we swapped the block cause i didnt want too take the chance of having another one go out soon. shes running well now. thanks again