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1994 CPI Engine Problems. Please Help.


1992s10cpi
01-23-2009, 01:42 PM
Recently i have changed over my olds cpi engine into my 1992 chevy s10. and i have been having starting and running issues with it. at first it would not even crank over and i had to replace the fuel pump. after that i had very few problems. and i finshed puting the truck together and took it down the road. bout a hundred yards down the road it just died. and wont hit a lick now.

Things i have checked.-
-Fuel Pressure-55 to 60 pounds. (normal)
-Thought it was the regulator at first and i changed it out. nothing changed
-I pulled the number 1 spark plug out and i am getting fire just fine.
-took one of the spider injectors out and it is shooting fuel just fine. just for the heck of it while i had the top of the intake off i turned it over and the engine ran. (backfiring of course) so i know the fuel system is working. I put the top of the intake back on and then it still wouldnt hit a lick.
-i got my bosses scanner and hooked it up and i got 2 codes 22 and 34. which are map sensor and tps voltage low. the tps is indicating .68 volts with the engine off and no throttle. while the map sensor is showing 3.78 volts. is this normal or abnormal? would it cause the enigine not to run?

Chris Stewart
01-24-2009, 12:11 PM
Was the ignition switch On when you checked the MAP?

old_master
01-24-2009, 02:10 PM
Fuel pressure is too low. The 4.3L CSFI and CMFI require 60psi to 66psi. Check it with the engine cold and off, ignition in RUN position, fuel pump running. Pressure must remain above 55psi for 3 to 5 minutes after the fuel pump shuts off.

MT-2500
01-24-2009, 03:38 PM
What engine did s-10 have before transplant?
Was all engine wiring and pcm/vcm changed over with the olds engine?
Are you losing spark to the spark plugs?

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