KA24DE RPM stumble - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

BlackRedX · 12-28-2008, 06:48 PM

Alright, I did an engine swap in a 1990. put a 91 KA24DE in it. This is what's done

KA24DE:
550CC Seimens deka F.I.
Greddy Fuel Rail for KA
no cat w/straight pipe
DOHC Manual ECU
Manual Trans
Timing is TDC w/ light
full tune up(plugs, wires, cap, fuel filter, etc.)
DOHC MAF from 95 Altima
New Radiator(ali)
New coolant sensor
Full engine coolant flush
AEM dry flow filter + piping
New O2 sensor

all the vacuum lines are hooked up, took out the smog pump and plugged it up, and the Charcoal/Carbon canister is still in use.

The car is running very rich and at idle is sitting at 17psi. According to the manual it should be sitting at 11psi at idle. The RPMS are sitting at 1000 when they should be sitting at 750. When I rev the engine it stumbles pretty bad and you can hear popping in the exhaust at around 4400 RPM.

Now could this because of the injector o-rings? They fit snug so fuel isn't shooting out. I just matched something up from a parts store. Should I just by factory 240SX ones and put them on so it is a super tight fight? cause I know it causes vacuum problems.

Also the MAF is off a 95 Altima. should I just go with the 91-94 DOHC MAF too?

I'm absolutely stumped at why this is happening. Ideas would be greatly appreciated. Thank You.

(Yes I've done the searchs and haven't come up with anyway that could be a problem cause I already checked hoses, EGR, Fuel Pressure Regulator, IAC 3 times)

BlackRedX · 12-29-2008, 11:25 PM

*sighs* Just so you know the DOHC MAF has the psi shoot to about 22 instead of the 17 its at right now. just a heads up.

alzahakar · 12-30-2008, 01:19 AM

Quote:

Originally Posted by BlackRedX

550CC Seimens deka F.I.
Greddy Fuel Rail for KA
DOHC Manual ECU
Timing is TDC w/ light

What's with the 550CC injectors. Stock are like 270CC iirc. That's what the ECU you have there is calibrated for. Timing on a stock KA24DE is supposed to be 20 degrees BTDC.

Quote:

took out the smog pump and plugged it up

Didn't know KA24DEs had em.

Quote:

The car is running very rich

I bet.

Quote:

and at idle is sitting at 17psi. According to the manual it should be sitting at 11psi at idle.

PSI of what? Intake pressure? Fuel pressure? Tire pressure?

BlackRedX · 12-30-2008, 12:41 PM

Oh yeah, sorry! I forgot to mention its for the psi of vacuum pressure.

The injectors I got are for later use for Turbo application, but the ECU will only run the fuel pressure that the ECU tells it to.

Also the smog pump comment I explained because only the SOHC came with them. Therefore, as previously stated, I removed it because it is an engine swap from SOHC to DOHC KA engine.

BlackRedX · 12-31-2008, 12:36 PM

any responses at all?

12-28-2008, 06:48 PM	#1
BlackRedX Join Date: Jun 2008 Location: that there Posts: 28 Trader Rating: (0) Feedback Score: 0 reviews	KA24DE RPM stumble Alright, I did an engine swap in a 1990. put a 91 KA24DE in it. This is what's done KA24DE: 550CC Seimens deka F.I. Greddy Fuel Rail for KA no cat w/straight pipe DOHC Manual ECU Manual Trans Timing is TDC w/ light full tune up(plugs, wires, cap, fuel filter, etc.) DOHC MAF from 95 Altima New Radiator(ali) New coolant sensor Full engine coolant flush AEM dry flow filter + piping New O2 sensor all the vacuum lines are hooked up, took out the smog pump and plugged it up, and the Charcoal/Carbon canister is still in use. The car is running very rich and at idle is sitting at 17psi. According to the manual it should be sitting at 11psi at idle. The RPMS are sitting at 1000 when they should be sitting at 750. When I rev the engine it stumbles pretty bad and you can hear popping in the exhaust at around 4400 RPM. Now could this because of the injector o-rings? They fit snug so fuel isn't shooting out. I just matched something up from a parts store. Should I just by factory 240SX ones and put them on so it is a super tight fight? cause I know it causes vacuum problems. Also the MAF is off a 95 Altima. should I just go with the 91-94 DOHC MAF too? I'm absolutely stumped at why this is happening. Ideas would be greatly appreciated. Thank You. (Yes I've done the searchs and haven't come up with anyway that could be a problem cause I already checked hoses, EGR, Fuel Pressure Regulator, IAC 3 times)

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12-29-2008, 11:25 PM	#2
BlackRedX Join Date: Jun 2008 Location: that there Posts: 28 Trader Rating: (0) Feedback Score: 0 reviews	sighs Just so you know the DOHC MAF has the psi shoot to about 22 instead of the 17 its at right now. just a heads up.

12-30-2008, 12:41 PM	#4
BlackRedX Join Date: Jun 2008 Location: that there Posts: 28 Trader Rating: (0) Feedback Score: 0 reviews	Oh yeah, sorry! I forgot to mention its for the psi of vacuum pressure. The injectors I got are for later use for Turbo application, but the ECU will only run the fuel pressure that the ECU tells it to. Also the smog pump comment I explained because only the SOHC came with them. Therefore, as previously stated, I removed it because it is an engine swap from SOHC to DOHC KA engine.

12-31-2008, 12:36 PM	#5
BlackRedX Join Date: Jun 2008 Location: that there Posts: 28 Trader Rating: (0) Feedback Score: 0 reviews	any responses at all?