Help: S13 KA DOHC runs way too rich - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

mike2016 · 01-25-2005, 08:56 PM

Sorry to start another tread but I've discovered more problems...

It's a 98 KA long block with DOHC S13 sensors, S13 wiring harness and ECU.

the car drives fine but consumes a lot of gas, less than 180 miles out of full tank. it has stock catalytic converter, but it shoots more black smoke and smells worse than my S14 SR with test pipe.

bad idle, it idles fine for 10 secs or so, then it will drop and bog, then comes back up for 10 secs then it'll do it again.

I used a timing gun to look at the timing, when the idle is dropping, the timing marks move to the left, then it comes back. Why?

at the same time I measured MAF signal output,

~1.6-1.7v idle @900-1000 RPM.
seems too high according to FSM specified 0.9v - 1.2v. I switched a few different MAF and they are all the same result.

- while idle is dropping, the MAF signal output voltage did NOT change.

Coolant temp sensor is in good working order, checked according to FSM.

injectors have no leaks.

fuel pressure is normal

fuel pump voltage did not change at anytime when the engine jerks.

when i did the swap, I had to replace the distributor with a S13 DOHC one, which I followed FSM to install and made sure No.1 is at TDC and the rotor is pointing at No.1 spark plug wire... so it can't be wrong right? i installed it the same way as I took the 98 distributor off.

01-25-2005, 08:56 PM	#1
mike2016 Zilvia Junkie Join Date: Oct 2001 Location: Los Angeles Age: 44 Posts: 538 Trader Rating: (0) Feedback Score: 0 reviews	Help: S13 KA DOHC runs way too rich Sorry to start another tread but I've discovered more problems... It's a 98 KA long block with DOHC S13 sensors, S13 wiring harness and ECU. the car drives fine but consumes a lot of gas, less than 180 miles out of full tank. it has stock catalytic converter, but it shoots more black smoke and smells worse than my S14 SR with test pipe. bad idle, it idles fine for 10 secs or so, then it will drop and bog, then comes back up for 10 secs then it'll do it again. I used a timing gun to look at the timing, when the idle is dropping, the timing marks move to the left, then it comes back. Why? at the same time I measured MAF signal output, ~1.6-1.7v idle @900-1000 RPM. seems too high according to FSM specified 0.9v - 1.2v. I switched a few different MAF and they are all the same result. - while idle is dropping, the MAF signal output voltage did NOT change. Coolant temp sensor is in good working order, checked according to FSM. injectors have no leaks. fuel pressure is normal fuel pump voltage did not change at anytime when the engine jerks. when i did the swap, I had to replace the distributor with a S13 DOHC one, which I followed FSM to install and made sure No.1 is at TDC and the rotor is pointing at No.1 spark plug wire... so it can't be wrong right? i installed it the same way as I took the 98 distributor off.