Greetings everyone, I am hoping some of you can help me to get this sorted out.

The Situation I have going here is this.

The base Engine is a Goodwrench crate 350 86 and prior
The injection system is stock of an 89 1500 ECU, Harness Intake and Throttle body. the ECU recieves a speed signal, but it reads double what the actual speed is.
The donor truck is a 94 s10 WITH a VCM. the VCM only reads oil PSI, and Tach readout from the Dizzy to control the Fuel pump, aswell as make the rest of the trucks electrical work.

I have 0 Vacuum leaks that I can find, I have checked all the hoses, TB gasket surface, EGR surface. The EGR Is not hooked to a working circuit, there is no vacuum supplied to the EGR solenoid, I can manually open the EGR and bog the motor at idle.

When running Warm up enrichment, it runs really well doesn't surge makes good power. as soon as it warms up it begins to surge arround 1800rmp up to 2800-3000rpm. after 3000rpm it stops surging and pulls hard.

I have ran it with out the O2 sensor connected to see if it makes a difference, there was no change in the warmed up surge. I changed the O2 out with a new Bosch unit and It didn't seem to make a difference either.

I have been running at arround 4° advance, as this is where it seems to be running best, as far as feel goes. I dont have a way to datalog yet, but I do have an Actron scanner that can do Live data.

I have been having this issue since my swap a month and a half or so, and really am trying to avoid causing damage to the engine. I do have a Carb, intake, small base HEI dizzy on deck If i cant get this sorted out, but would really like to keep the EFI setup. Unfortunately I cannot afford to buy an EBL setup at this time, Its something I have been looking into, but isn't int he financial cards any time soon.

Any help is appreciate-.

Thanks in advance


Pic of said project