I’m sure this has been asked before and I apologize in advance. I’ve tested every wire i could think of as to why my fuel injectors (brand new injectors.. TPS.Fuel pressure regulator) won’t release fuel.after reading my MOTOR Manual I did notice that pins 15/16 are grounds. How they aren’t grounding out with or with the ignition on. It say if my OHMMETER is more than .5 (it’s 1.4) I need to repair ground circuit for high resistance to ground eyelot. I guess my question is how do I do that? And second question I have is the ecm supposed to be ground somehow?

please note I am no mechanic just a man trying to get his truck back on the road and I was allows told no question is a stupid question.

thanks in advance

 

Does the fuel pump come on with initial key on? It should also fire the injectors(for a second) to prime the motor for starting. You won't see a ground till after the motor starts. Are you getting positive power from the asd relay?

 

I have an inline pump on a switch, however the one I had on it didn’t have enough psi I guess to open the injectors up if that sounds right. So I’m guessing I need to start with the correct psi fuel pump that will allow the injectors to release the fuel in which that should get me to a starting point and that would create the ground to the injectors.

 

TBI only really wants about 15 PSI, doesn't it?

 

Thats what it says. Bad part is I bought the Holley mighty mite and it’s only 7psi. One more question. Fuel pressure regulator how does that work exactly? Does it just regulate the amount of fuel that goes into the injectors or regulates the amount of fuel that gets returned? My thoughts were since the pump had the incorrect psi the regulator wasn’t opening up to allow the fuel into the injector

thank you for your help on this I couldn’t find no where that had the information on why I only had power and no ground on the injectors. I thought my ecm was cooked

 

Regulator maintains a target pressure. PCM controls when the injector opens. That is pressure independent. But, if there isn't sufficient pressure, you get inadequate fuel flow, and the engine either runs terrible, or not at all.

Of course, if your pump doesn't put out pressure greater than what the regulator wants to keep it at...... nothing returns to the tank.

 

Did you remove the pump in the tank? Sounds like you need a fuel pump assembly(one in the tank) it's regulated and comes on when the pcm tells it. I know the fuel pump assemblies in the 89/90's are impossible to find(or at least they were). You can retrofit the pump from a 91 i believe. When i had my 90 i think i got one of the last fuel pump assemblies before they became extinct.

 

Yes I didn’t remove the fuel pump from the tank and put an inline fuel pump on it. Will that not work? I’ve tested all the wiring from the distributor to the ignition module to the coil and I’m getting power every where but not to the injectors themselves. Could it be my ecm itself? I’ve looked online for a new one and yea they are impossible to find as well. Not sure if I can use a 88 model instead or not. Your thoughts?