Background first. My car sat for a bit and I didn't think to put any additive in the gas. It ran horribly after and I found the tank ended up rusting, so I put in a new tank and a Walbro fuel pump.

It runs better, but feels almost like an NA 4 cylinder because of a major lack of torque. It is a lot smoother, but does have a slight stumble in the idle. I changed the spark plugs and didn't solve the problem. It's throwing P0306 (cylinder 6 missfire) and P0300 (random/muliple cylinder missfire) codes.

Anyone have any ideas on what it could be? The only things I could see left would be bad coils, bad O2 sensor, or maybe bad cats.

 

And I don't have any performance mods yet.

 

Also if it is the injectors would I run into any problems running a larger aftermarket set while stock? I plan on going FI in the future and figure if I need to replace them I might as well do it once instead of twice.

 

when you changed plugs did u notice any oil on the cylinder 6 plug?

 

No. They all had dry carbon, but none showed moisture.

 

how about changing the fuel filter, then running an octain booster/injector cleaner through it. if the car sat long enough for the tank to rust then the filter is probably full of rust, also with the gas seperating it may have crystalizes on your injectors and needs to be cleaned.

 

If its showing a misfire code try changing ur plugs and wires I had the same problem on my jeep back in the day and it turned out two of my spark plug wires went bad

 

If its showing a misfire code try changing ur plugs and wires I had the same problem on my jeep back in the day and it turned out two of my spark plug wires went bad

 

The fuel filter is just a mesh net at the bottom of the fuel pump. I cleaned it when I switched pumps. I also changed the spark plugs, but it doesn't have wires. The coils sit right on top of the plugs.

Also a new update, twice today it didn't want to start good. Once I tried twice before it started up and the second time it took 5-6 times trying before it started.

 

Oh my bad lol I'm new to the z's I'm thinking its definitely in ur spark circuit somewhere tho

 

No problem.

New update. I started getting spikes of major power loss when getting into the throttle. Also If I laid into the throttle the RPMs would raise, but there would be no acceleration. Similar to holding in the clutch and feathering the gas.

 

?

 

Your injectors are probably thrashed. Have them cleaned/replaced. Don't get bigger injectors until you go FI and have some sort of FMU or aftermarket ECU... your car is going to run pig rich otherwise.

 

I just ordered some oem injectors, so hopefully I'll have it figured out very soon.

 

Hi did you end up fixing the P0306 problem after you change new injectors? Because I am having the P0306 problem and I change new coils and new valve covers but not fix yet!!!