CEL Light one day, runs fine the next?

Danielrod61

New Member
Registered VIP
Okay, so I my 93 b20 hatch is acting up. It started about 3 weeks ago.

3 weeks ago, driving home and CEL light comes on, car is running fine besides a small iregularity in the idle. I drove it home parked it. That was on a Friday afternoon. Opened the hood and there was a noise coming from the upper timing cover. I was kinda scared, but I went to bed after, I was too tired to mess with it. Saturday afternoon I went to work fine. No CEL no weird idle. Weird.

Last week on Wednesday I'm headed home from church and a CEL comes up. Once again I ignored it because it sounded fine. I did open the hood both times and visually inspect the engine. A slight noise was coming from my upper timing cover, but nothing HORRIBLE. Thursday I woke up and was headed off to class. I turn on my car and it goes to 1k immediately, but then starts bogging up and down from like 100-500 rpm. I didn't know if I'd make it to class. I took it to school and when I got to my auto class we pulled it in. My teacher and I both figured it had jumped timing. So, I left it there over the weekend.

Today when I got to class I went to finally check the ecu by jumping the wires to get the CEL to blink. BUTTT... my car doesn't have the plug to jump. ANDDDD it's running fine. Haha.

I want to figure the issue out though. My teacher looking inside my ecu and it's all gross. First thing is to get a new ecu. Any suggestions?

Car has fresh oil.

coolant is full.

Fresh tune up (spark plugs, wires, rotor, cap, fuel filter and fuel pump)

It's a b20z2 with a virgin p06.

Any input is much appreciated.
 

codeman76

New Member
Thats about what they go for give or take a few bucks. It would be worth it cause it will run the b20z alot better then the p06. Another option is to get the P06 chipped with a b20z base map.
 


Danielrod61

New Member
Registered VIP
Even better- My buddy is giving me his for $30 :p

ANy chances the issue could be a failing throttle position sensor?
 

codeman76

New Member
Thats a good price just make sure you get a 5 speed ecu if your car is 5 speed and an auto ecu if your car is auto.. I would swap the ecu first then see if the problem persists.
 

codeman76

New Member
On my 92 eg it is located just to the right of the glove box in a fake green connector i don't have to remove the kick panel to access it.
 

Danielrod61

New Member
Registered VIP
So, I replaced the Throttle Position Sensor, and it seemed to idle better. We'll see if the CEL comes on again.

Here's the old sensor:



I found something funny when I was putting the new sensor on though. It's a hose loose at one end with a bolt in it.

It's connected to this:


Here is the tube about 12"-18"
 


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