Missing/ pinging ONLY when warm, why?

[n2x4]

I had posted earlier with my problem, but I know a little more now.

Until my car warms up, I have no troubles. Not long after the fan kicks on it will start to stumble and sounds like a miss, but only when it's warm.

What could cause something like this? I checked the codes and I don't have anything new (need to fix code 35, but it's been there a while).

I put new NGK plugs in with no change, tried to test the wires by misting them with water, but nothing changed. Could it be the coil? It has the Diamond coilpack on it, but I don't know how old it is (car has 174k on it). I tried testing it after it was warmed up with my voltmeter, but it showed 21ohms of resistance between 1&2 and 3&4, but could it still be bad?

I'd really appreciate some help, thanks guys!

OH, and edit-

It's a 90L, 5MT. Reading other threads on missing, it seems it's not as consistant as my case. With or without a load on the engine, it will miss. When I'm just sitting in neutral, I can take it up to 3k and just let it sit and it will miss. And the miss isn't always constant. It might miss 3 times in a row with a pop pop pop, or it just might pop once, but it will keep popping and you can watch the tach drop a little each time, and then climb back up.

[evolutionmovement]

Might be a combustion chamber issue. I'd run some sea foam through and check the cooling system. My fans don't usually come on unless in summer traffic or with the A/C on. Either way, you shouldn't be pinging so you're knock sensor is probably bad to start. If it's a miss instead, I'd replace the wires. Before I got Magnecors I went through a set every year. Plugs were never a problem.

[n2x4]

I've already replaced my knock sensor with the revised white clip one. I'll try some new wires and let you know.

[sammydafish]

could be plugs, a bad injector is a likely culprit. Also make sure your engine isn't running a little to hot (clogged radiator, sticking thermostat). That can hurt things too. Your fan being on a lot leads me to think something along those lines. A NA Subaru should be able to run all day without needing the fan to come on save for the hottest days or when running the AC.

[n2x4]

well, I ran seafoam through it, got some nice white smoke, but as usual, the fan kicked on for about 20 seconds. After it was off, I sat in the car, held it around 2k, and it started doing it again.

I'll check the coolant and put new wires on it later today.

[scuzzy]

I'm running an EJ22T block as NA with NA injectors and the NA ecu - mine would miss every now and then, few in a row sorta deal, then steady out but only when not under a load.

to me it just sounds like you could have injector problems, mine misses because of overfueling - it did it for the longest while, and now it doesn't do it at all.

[sammydafish]

could be the AFM too.

[n2x4]

Got new wires and installed them, still does it. Gah! I can't figure this out.

[n2x4]

Ok, got a new coilpack, still same thing

BUT! I'm narrowing this thing down. Here's the deal though, I sat in the car while the fan was running, I held it at 2k, it was fine, AS SOON AS the fan clicked OFF again (like 20 to 30 seconds) it would putt and pop like before. The R's would drop and go back to normal. It happens the instant the fan kicks off. Is this now an electrical issue?

[scuzzy]

I say you live with it till it gets worse.

[n2x4]

I can't live with it, the problem is serious enough that the car isn't driveable. When you try to drive it while the power is jumping up and down, the car lurches horribly.

I've tried to clean the IAC valve, tried resetting the ECU, I let it run disconnecting one injector at a time, but it was still acting up, dismissing the idea of a bad injector.

I really think it has to do with the fan kicking on. It's like the car hits some temp, turns on the fan, and some sensor is going bad when it thinks it's at a certain temp? Maybe I'll try the temp sensor if it's cheap enough. I wanted to hook up the scan tool to check actual temps, but I couldn't get it to read my ROM ID.

[scuzzy]

I can't live with it, the problem is serious enough that the car isn't driveable. When you try to drive it while the power is jumping up and down, the car lurches horribly.

I've tried to clean the IAC valve, tried resetting the ECU, I let it run disconnecting one injector at a time, but it was still acting up, dismissing the idea of a bad injector.

I really think it has to do with the fan kicking on. It's like the car hits some temp, turns on the fan, and some sensor is going bad when it thinks it's at a certain temp? Maybe I'll try the temp sensor if it's cheap enough. I wanted to hook up the scan tool to check actual temps, but I couldn't get it to read my ROM ID.

have you changed plugs?

[n2x4]

Plugs were the first thing I tried.

Got a new coolant temp sensor and cleaned the contacts for the sensor that goes to the guages, still same thing. I've seen it enough that I can tell exactly when it'll happen.

After about 5 or so minutes the fan kicks on for about 30 seconds, shuts off. 30 seconds later, it kicks back on again. Just a FEW seconds before it shuts off again, it starts acting up. I'm to the point where I don't know what else to try. I'll have to call the stealership. I really need my car, but I just can't figure it out.

[n2x4]

FIXED!

Turns out it was my timing belt, stupid thing. I guess it had skipped some teeth and threw the timing off. Must have run some default timing until the fan kicked on, and then it went to read the cam sensor and started acting bad when it was off. Runs really nice now. I can't complain about anything else I did to it, basically got a tune up out of it anyways.