I havea 94 toyota pick up. 22re 5 speed. I first went to look at the truck it had a minor missfire. Like it needed a tune up. The problem has gotten worse andworse. I did complete tune up, checked all fuses and relays . The cat was glowing so I disconnected that, still same problem. The truck idles, sort of has a missfire at idle. When you try to give the truck gas it hesitates and back fires, sometime through the intake. If you gradually give it gas you can get into higher rpms. I tritried to check timing yesterday and the timing mark was jumping all over, the timing light was not steady like the spark going through the wire is not steady, again like a misfire. I'm stumped, have been getting all kinds of "fixes" from everyone. I don't have a whole lot of $$ its my project. Any advice, tips etc will be greatly appreciated!

 

What's a 'complete tune-up'??
Did you do a valve adjustment? Replace o2 sensor??

 

Complete tune up meaning plugs wires cap rotor, I doubt 02 sensor would have anything to do with this issue. I'm thinking the pickup in the dist or maybe thecoil

 

Tried removing one plug wire at a time and see if you can see if it is just one cylinder? I had a bad injector connector that was the reason one cylinder wasnt firing. It can be on the spark side or fuel side.

 

It doesn't change when doing that

 

Is the o2 still hooked up? Throwing any codes?

 

You pulled one plug wire off at a time while the engine was running right? And it doesn't change?

 

Yes, a slight change, but nothing drastic

 

Take a old spark plug and put in the wire with the engine running, hold the body of the plug to metal and see if it's sparking, on every cylinder.
When you pull a plug wire off with the engine running it should be a drastic change because your losing a cylinder.

 

Well it doesn't and I don't know why, I'm confused as to why the timing mark is moving, why the timing light wasn't working properly when on the plug wire, like the spark was not correct

 

Ok so I figured simething out and maybe this will help in finding out the issue. The timing jumps all over with the diag port jumped, its jumps all over with the tps plugged in. It idles good and the timing mark will stay in one spot when the tps is unplugged...

 

Test the TPS.