I have a 78 4x4 Blazer with the small block 350. I have about 5000 miles on a new engine. Also, not sure that it matters but it has the manual 3 speed transmission with granny gear.

My problem stated about a year ago. My truck just wouldn't start in the mornings. I changed out the carb (edelbrock 650) for one with a choke. It worked for a while but after a couple of months I started having the same issue. I checked and found that I was not getting a spark so I replaced the the pugs, wires, rotor, and cap. Still no change. Changed the coil on the distributor. No change. I got a new distributor but I had to go out of town. My wife had a new mechanic, a friend of a friend, come over and change out the distributor. He gave me a whole sales job about needing a new carb, new manifold, etc. The truck would barely start, and when it did I got no acceleration. I messed with the timing enough to get it to a mechanic. He adjusted the timing, but the engine seemed to run high. I took it back in and they did some adjustments and put the edelbrock carb back on, but then the engine ran hot (about 210F). Further adjustments and I am back to limited acceleration in 2nd and 3rd gear and engine is very hot, about 230F. I feel like there may be more than one problem, but I don't even know where to start.

Help please!
David

 

The low power and running hot are signs of retarded timing. Are you checking it with the vacuum advance disconnected? What are you setting it to? IIRC, the spec is something like 8 degrees BTDC.

 

Thank you. I checked and timing was actually at 8 degrees ATDC. Changed it to BTDC and the power is back. Now running at about 200F. That's hotter than usual but is that ok/normal?

 

If you have a 195 thermostat, 200 is probably about right. Definitely nothing to worry about.

 

Awesome. Thank you for your help!