Mdz320

I've found and replaced the injector fuse and one of the ecm fuses. No obd1 codes posting. I'm wondering what other fuses and such might I look into?

DynoDave43

iTrader: (11)

Welcome aboard Mdz320!

By the statement above, are you seeing that you are not able to get the ECM to flash codes? Or that you cannot obtain a connection to the ECM with a scan tool?

Tuned Performance

iTrader: (92)

Working on motorhomes dave lmao

DynoDave43

iTrader: (11)

What I know about this stuff you could put in a thimble.

But at the end of the day, it's a GM engine with Rochester TBI EFI. We had two of these in the family over the years.

Schurkey

What is the battery voltage at the battery? What is the system voltage at the ECM fuse?

If you don't have "code 12" you have an ECM fault or a power-to-the-ECM fault, or there's a fault in the Check Engine Light circuit including a potentially-popped light bulb on the dash. CONNECT A SCAN TOOL.

Does the engine crank? Do you have spark? Will the engine run if you splash a little gasoline down the throttle body?

Does the fuel pump prime when turning the key from "Off" to "Run"? If so, what is the fuel pressure? How old is the fuel filter?

Mdz320

I jumped the obd1 after I replaced the fuse. Read, 12 repeating. I only checked the ECM fuse because I notice there was no check engine light. My next step is to find someone who can get into the tight spot to check the rest of the fuses and maybe the relays for the fuel pump and such.

Mdz320

Yeah. Its just a 91, 454 tbi on a p30 chassis. No need to get RV in the mix to cause confusion.

Mdz320

I have code 12. Engine cranks and sparks. Fire with starting fluid. Yet to be determined if we can hear the fuel pump. I need a second hand.