r33 rb5de misfire and bad idle

[heyzah]

Ive just bought a r33 rb25de that was sitting for 5 years. Did simple service by changing the fluids, filters, spark plugs and coolant temp sensor. Sadly the car misfires badly, idles badly (sounds like its going to stall) and over heats. The over heating is probably due to the broken water pump.

Ive done a bunch of research and it seems like there is a ton of variables that could cause my problems. I was wondering where would be the best place to start to help fix my problems?

[Ben C34]

Sell the car

[KiwiRS4T]

Did you drain the fuel tank and change the fuel filter?

Check the coils for shorting and then either clean and insulate them or replace them (and try gapping the plugs down to .63)

When you replace the water pump do the cambelt etc.

[Duncan]

Not sure exactly what you mean by broken water pump, but if coolant is not flowing properly you need to start there

Also, if it has been sitting 5 years everything in the fuel system is a problem. Definitely need to flush the tank and replace the filter like Bob said, but it is likely fuel pressure regulator, lines and even injectors will be gummed and failed. I'd replace all lines, FPR and have injectors flow tested before trying much more.