Greetings all. I just bought an 02 S10 with 4.3L and 155k miles. Engine will crank but not start. Previous owner said it just quit one day and not started since. I checked for spark at the coil. Have spark although it looks a little weak. Checked fuel pressure, 62 psi with pump running but immediately drops to 0 when pump stops. Suspected fuel pressure regulator. Pulled plenum and pressurized system. Didnt see any obvious leaks with pump running or off except for a tiny bit of gas in the regulator tube. The bottom of the spider assume was a little wet too. The lower plenum was dirty, like oil dirty. Not what I was expecting if fuel leak inside plenum. No obvious external fuel leaks. Should I replace the regulator, spider assume, something else? I could use some advice. Thanks.

 

hi thunder ! start with the easiest and cheapest first ! you say the fuel pressure is weak ? then change the fuel filter, I had to do that on my 99 blazer when I first got it ! if the spark is weak then that tells me the coil or module is weak and not able to fire the plugs ! check the plugs for wetness ! also did you check the timing ? maybe it jumped time ! it takes 3 things for a engine to start and run, it takes good compression, a good strong spark and good fuel pressure and volume !

 

Success!!!! The truck is alive. I ended up replacing the CPSI spider fuel injection with a direct fit MPI unit. The swap was very easy. Once I got everything back together it fired right up and ran. Now on to the next problem.