thermostat problems!

[gen1ranger83]

i have a 83 ford ranger and i changed the thermostat wich was an easy process but when i started the engine there was no power and it was hesitant to start without alot of pumping.when started i have to hold the throttle wide open for it to barely idle and the headers were glowing orange/i figured i put it in the thermostat wrong and broke it/so i put the old one back in just the way it came out and it started a lil easier still with some pumping but was still lacking all the power it had before the repair.?????? it ran great and idled great before the repair any suggestions on what is wrong and what i should do?

 

[Earl43P]

I don't believe your thermostat replacement had any effect on how the engine runs.

I do believe you may have disturbed something like a vaccum line or electrical connector. Give it a good inspection, concentrating on everything you touched.

The thermostat has nothing to do with it being hard to start and running poorly, IMO.

Check the plugs, plug wires, timing, etc. Could even be the fuel pump (mechanical in your case). Sounds like it is starving for fuel or maybe the timing belt jumped teeth.