I have a 86 302 f.i. that is giving me trouble. It never has quite run right since we bought it, but now has become worse since it sat. Tank was nearly empty, but had maybe a gallon of fuel in it. We put five gallons of gas in it, and attempted starting. It would not fire while cranking, so I squirted fuel in the intake and it took off. Spitting, sputtering, idle is rough, and has no power. Eec tested fine and is working, bright blue spark, timing is at 12*. Fuel pressure sits at 32-35 idle, 40 when I rev it up. I can not get it to rev out. Fuel pressure does not change when the truck begins to stall. I'm thinking it has a bad bank of injectors, or a bad air speed sensor. Any insight?

 

Sounds like dirty Injectors.

 

What I was thinking, that or a bank of injectors isn't working. Are they port fired, or are they bank fired? What has me stumped the most is it will not fire while cranking unless you give it gas in the intake or a quick squirt of engine candy.

 

I honestly can't remember, my truck originally had that FI 302 until it died then I swapped to a new 302 carb setup. Sounds like it's starving for gas based on you having to add some to get it to crank up. Maybe prime the system by turning over the key (let the fuel pump prime the fuel system) then press onto the gas twice & repeat 2-3 times & see if it turns over. Does sound like an injector issue.

 

Has fuel pressure instantly, and will hold pressure after key is shut off. I agree it's fuel, but why will it fire after a little gas in the intake?

 

I think you answered your own question there. Fuel pressure is obviously making it to the rail but not into the combustion chamber which leads back to the Injectors.

 

Agreed, but I'm just thinking that there should be some spitting and sputtering if it will run some afterwards.

 

I'd buy a cheaper set of 8 online just to verify it is the Injectors without hitting your wallet heavy, at least if it does start you know what the problem was right away & if it wasn't than you know you have a new set of injectors installed & you can investigate what other issues might be the root cause.
Some places do injector services, price them to see which one is the better deal.

 

Do you have power to your injectors?

 

Have not verified that yet. Looking to get a noide light soon.

 

With the key ON, you will have 12v dc to the Injectors.

 

Got ya, then I assume the computer grounds them?

 

Correct, 4 at a time....

 

Electronic Engine Control - Gary's Garagemahal (the Bullnose bible)

 

Thank you, that's a big help. I was looking in the FAQs for that, but must have skipped over that...