1994 K1500 with 5.7TBI & 4L60E

[NickCuthy]

Hello Everyone!

I have taken on an adventure to completely redo my 1994 Cheyanne K1500. Right now i have a fully rebuilt 5.7 that we reinstalled the TBI set up on, we have been having nothing but issues with the engine starting terrible once cold. It is very RICH once fired up and it does not go into high idle all the time which then sends it down to 500RPM and sits there and just pumps out fuel for 3-5min. I have replaced fuel pump in tank, injectors, installed a summit adjustable fuel regulator. i am getting 10.5psi at the throttle body, if i change the psi up or down there is no difference, rebuilt the TBI multiple times, replaced all the sensors on the engine 2-3 times and the engine still does not run properly. Once engine is warm the truck runs great and has tons of power. I did do a EGR delete but have not found a chip yet to tell the ecm, could that be the issue? I have fully rebuilt the transmission and transfer case also. I have changed the intake to a edolbrock performer intake with a spacer to adapt to TBI, I have checked for vacuum leaks, nothing.

I am thinking of going to a sniper efi system, i talked to them and because its a 1994 i would have to buy a separate transmission controller, is that correct? and if so what is the best one that will not cause me any issues. Holley could not tell me what sniper system would be best for my set up so any feed back would be great. I have also considered just ripping it all off and going carb also.

 

[Schurkey]

Stuff the Sniper.

Connect a scan tool, find out what the computer wants you to know. Verify ALL the sensors and computer outputs with the scan tool.

 

[NickCuthy]

Thank you, I have done that with multiple computers, only code that comes up is EGR delete code. Have checked all sensors and they come in spec

 

[Erik the Awful]

A Holley Sniper is not a fix for not being able to diagnose the problem. It's a solution for having a cam too big for the TBI. I know, I have a Sniper, and it's been a learning curve. Yes, you will need a transmission controller. If you do decide to go this route, get the basic 4-barrel Sniper. Holley sells them refurbished for under a grand. You'll also need to upgrade your fuel pump to the Vortec pump, and you absolutely need to spend the extra $15 for the throttle arm extension or you can damage your throttle lever.

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Why did you delete the EGR?

Have you looked at the injector pattern while it's running? My son's '94 was running like garbage, and then we noticed one of the injectors wasn't spraying. We'd replaced the injector pigtail, but we had to cut it back further and re-splice it.

Being able to read the data stream is important for diagnosing problems. Do you have a scan tool that can show data stream, or just trouble codes?