TBI problems

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daw5spd

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Hi folks, I just reinstalled my 7.4 in the 94 K2500 4WD after having it redone; sleeved, bored, new pistons, new cam & lifters etc., etc. Tried to start it today, the TBI injectors are apparently spraying 100 percent (big spray fan of gas from both injectors at startup attempt) and of course flooded. LOTS of gas on the plugs. I'm an old Holley guy, working on FI stuff is a new challenge. Any suggestions to start the trouble shooting process?
Thanks
 

Schurkey

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Connect a scan tool, look at the sensor data.

At startup, the coolant temp, the MAP, and throttle position will be very important.

Verify no grounded, pinched, or mis-routed sensor wires.

Did you have the throttle body apart? No missing or torn seals for the injectors?
 

daw5spd

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Thanks for the reply, I'm working on checking the wiring, the throttle body wasn't disassembled and looks to be working as advertised.
 

thinger2

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Hi folks, I just reinstalled my 7.4 in the 94 K2500 4WD after having it redone; sleeved, bored, new pistons, new cam & lifters etc., etc. Tried to start it today, the TBI injectors are apparently spraying 100 percent (big spray fan of gas from both injectors at startup attempt) and of course flooded. LOTS of gas on the plugs. I'm an old Holley guy, working on FI stuff is a new challenge. Any suggestions to start the trouble shooting process?
Thanks
Timing, Set it to tdc before tou do anything else.
With the dist wire unplugged.
Let it get warm untiil the thermostat opens .
Check the timing again.
Its all of it all damn bit of of it just a little bit of ******* around and tweeking and tuning.
This is easy easy easy easy.
Always keep in mind, some nut jobs are gatekeeping about old chevy trucks.
Hi folks, I just reinstalled my 7.4 in the 94 K2500 4WD after having it redone; sleeved, bored, new pistons, new cam & lifters etc., etc. Tried to start it today, the TBI injectors are apparently spraying 100 percent (big spray fan of gas from both injectors at startup attempt) and of course flooded. LOTS of gas on the plugs. I'm an old Holley guy, working on FI stuff is a new challenge. Any suggestions to start the trouble shooting process?
Thanks
set the base timing.
Base timing off will fire hose fuel and wash the rings if you let it go toi far.
Set the base timing
 

thinger2

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Yeah, been a small block guy all my life, either Ford or Chevy. Somehow, the 7.4 redline of 4000 rpm just seems...wrong....
Back in high school and for a couple of years after, I had several 390 FE cars and a couple of big block Mopars.
Great for melting tires.
Back in the 1980s, street racing was huge up here.
Seattle and King County got rid of the Dodge 440 cars and gave them all small block Diplomats.
Then they put millions into a radio system that didnt work.
And, to this day, we only have one helocopter.
All you had to do was put a plate from your junkyard collection on the car and run it.
They didnt stand a chance.
The only exception was the state patrol.
The Washington troops kept the big block cars and they knew how to build them.
We didnt race on the freeway much because them boys would wind those old Furys and Polaras up and drive you into the ground.
Im still a big FE block fan. Evan though they suck gas at an incredible rate and you need 3 freinds and a hernia operation to pull the intake off.
I finally made the shift to small blocks when I figured out that I was getting my ass kicked by small block Camaros and Mustangs and Mavericks.
They were doing it for maybe 1/3 rd of the money that I was spending and driving it home.
I drove mine home too.
On pushrods that looked like a dogs hind leg and valve spring chunks like confetti at a parade for losing.
 
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