So the other day my EJ swap into my wagon started running poorly. I may have gotten on it a little hard, but never exceeded 5k RPM. It idles and starts just fine but hesitates under throttle and is lacking power when cold or warm. There may have been some crud in the gas tank but the issue was not gradually happening, it started right away.

 

Heres what I have tried thus far:

 

Filled the tank - was low

Replaced fuel filter

Upgraded to XT6 fuel pump

Checked for vacuum leaks

Installed CEL - Not on

Replaced plugs and wires

Blew out fuel lines with compressed air

 

 

Anyone have any ideas? I was planning on checking cam timing next. I do not even know where to start with sensors or how to check them without just replacing. O2, TPS, CTS MAF?

 

Thanks in advance!

I had some problems with lack of power in my ej22 before, cleaning the IAC seemed to help with response. Its something you can do without replacing sensors. What year ej22? I have a service manual for imprezas 97-2001 and it has some stuff on testing sensors.

From what you describe, it could be a bad tank of gasoline. Maybe some water in your last tank of gas. Try adding a "dry gas" product to the gas tank to see if that helps.

From what you describe, it could be a bad tank of gasoline. Maybe some water in your last tank of gas. Try adding a "dry gas" product to the gas tank to see if that helps.

 

Forgot to mention I did do seafoam, but maybe I'll do some HEAT in there for this tank.

 

Changed out the MAF. Same results.

Forgot to mention I did do seafoam, but maybe I'll do some HEAT in there for this tank.

 

Changed out the MAF. Same results.

 

Yes, HEAT is a brand name for dry gas. I remember years back, my brother had a Mazda that got a tank full of gas with some water. Like yours, his car would idle okay, but put that engine under load, it would hesitate and lack power, and want to back fire through the carb. It took him several tanks of gas, and dry gas added to each new tank of gas to finally get rid of the water. Seafoam is a good product, but will not address water in the gas.

 

Try the HEAT, you will know within 10-20 miles if it helps your engine to run better. If not, it has cost you very little.

Try the HEAT, you will know within 10-20 miles if it helps your engine to run better. If not, it has cost you very little.

 

Gonna get some in there tonight.

Got some HEET with injector cleaner in there. We shall see if that makes a difference. Any other suggestions in the meantime?

Based on description it kinda sounds like it's misfiring under load.

Since you replaced plugs and wires (assume you checked plug gap and made sure it was in spec), do you have another coil pack to try?

Timing isn't hard to check, set the crank at TDC and check the arrows on the cam sprockets. They should point straight up. If one is off, the belt jumped on that cam. If both are off the belt jumped the crank sprocket.

Well............ Not sure if replacing a torn CV fixed it. Maybe it just wanted to do some offroading, cause I did plenty of that this weekend. Could have just been the HEET with Injector cleaner too Either way its running well again and I am happy. Replaced the O2 sensor just for good measure too.

 

Thanks for the replies!

 

Looks to have been related to dirty injectors or water in the fuel.