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

DriftDamage · 01-28-2010, 09:47 PM

Ok so here is the run down. I bought an 89 240 with a 93 KA24DE swap in it. Completely stock. At first the car was having problems with the idle. It was too low and would come up and down and would sometimes die. I tried to fix this problem by moving the IACV valve on the back of the manifold to raise the idle. I followed instructions/write ups I found that included disconneting the TPS while doing so. This never worked. I tried to adjust timing a bit by moving the position of the distributor cap and this did nothing either. Raised a bit but same problem so I kinda gave up on it to figure it out another time.

Well today I replaced the stock intake with my aftermarket one and suddenly it idles WAY too high. Again I adjusted the IACV valve ALL the way down and it still has a very high idle. I tried to adjust the distributor cap again and no difference. The throttle cable also has slack and the throttle body is all the way down so I know the wire isnt pulling it up any.

Anyone have any suggestions? The vacuum hoses also all seem to be in the right place.

junn · 01-28-2010, 10:18 PM

could me ur MAF.......or maybe ur ecu

DriftDamage · 01-28-2010, 10:28 PM

Quote:

Originally Posted by junn

could me ur MAF.......or maybe ur ecu

Now that you mention that it could be but I wasnt sure if that could be it. It seems to still have the 89 KA24E MAF. Its a 3 prong connection to the MAF. The one on my other 240 which was a 91 had a 4 prong connection to the MAF.

IMO I dont think this could be a problem buuuut it was something that I noticed was different compared to my other 240.

Also as for the ECU, I disconnected the battery for a few hours to see if the ECU would reset. Not sure how thats done but it was worth a shot. Came back and reconnected and same problem. =/

DriftDamage · 01-29-2010, 12:05 AM

Could the MAF really cause this problem? Im thinking tomorrow I might try switching out my ECU and splicing in the connection to the MAF that was on my other car...

Lookin at the write up for a KA24E to KA24DE swap and the use of the older MAF might suggest the original single cam harness might have been used with its old parts. Thinkin maybe replacing these parts could help....? o.O

slothonaleash · 01-31-2010, 03:49 PM

Clean your maf with electrical contact cleaner, look for vacuum leaks, and make sure you're adjusting your timing correctly, then check it again. You gotta disconnect the tps and shit when you adjust your timing.

jdm213 · 02-04-2010, 11:52 PM

Quote:

Originally Posted by junn

could me ur MAF.......or maybe ur ecu

damn your avatar has some big knockers !

SoBay240guy · 02-05-2010, 10:18 AM

Start by verifying that it has a DOHC ECU,
the MAF needs to match the ECU,

I know people have gotten the SOHC ECU to work on DOHC motors,

it has regular DOHC injectors though right???

01-28-2010, 09:47 PM	#1
DriftDamage Leaky Injector Join Date: Jun 2008 Location: El Paso, Tx Age: 36 Posts: 65 Trader Rating: (1) Feedback Score: 1 reviews	KA24DE High Idle Ok so here is the run down. I bought an 89 240 with a 93 KA24DE swap in it. Completely stock. At first the car was having problems with the idle. It was too low and would come up and down and would sometimes die. I tried to fix this problem by moving the IACV valve on the back of the manifold to raise the idle. I followed instructions/write ups I found that included disconneting the TPS while doing so. This never worked. I tried to adjust timing a bit by moving the position of the distributor cap and this did nothing either. Raised a bit but same problem so I kinda gave up on it to figure it out another time. Well today I replaced the stock intake with my aftermarket one and suddenly it idles WAY too high. Again I adjusted the IACV valve ALL the way down and it still has a very high idle. I tried to adjust the distributor cap again and no difference. The throttle cable also has slack and the throttle body is all the way down so I know the wire isnt pulling it up any. Anyone have any suggestions? The vacuum hoses also all seem to be in the right place.

01-28-2010, 10:18 PM	#2
junn Zilvia Addict Join Date: Apr 2008 Location: lynwood/cpt Posts: 777 Trader Rating: (7) Feedback Score: 7 reviews	could me ur MAF.......or maybe ur ecu __________________

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01-29-2010, 12:05 AM	#4
DriftDamage Leaky Injector Join Date: Jun 2008 Location: El Paso, Tx Age: 36 Posts: 65 Trader Rating: (1) Feedback Score: 1 reviews	Could the MAF really cause this problem? Im thinking tomorrow I might try switching out my ECU and splicing in the connection to the MAF that was on my other car... Lookin at the write up for a KA24E to KA24DE swap and the use of the older MAF might suggest the original single cam harness might have been used with its old parts. Thinkin maybe replacing these parts could help....? o.O

01-31-2010, 03:49 PM	#5
slothonaleash Zilvia Addict Join Date: Jan 2007 Location: Columbus, Ohio Age: 29 Posts: 745 Trader Rating: (4) Feedback Score: 4 reviews	Clean your maf with electrical contact cleaner, look for vacuum leaks, and make sure you're adjusting your timing correctly, then check it again. You gotta disconnect the tps and shit when you adjust your timing.

02-05-2010, 10:18 AM	#7
SoBay240guy Zilvia Member Join Date: Aug 2006 Location: So. Cal. Age: 36 Posts: 191 Trader Rating: (0) Feedback Score: 0 reviews	Start by verifying that it has a DOHC ECU, the MAF needs to match the ECU, I know people have gotten the SOHC ECU to work on DOHC motors, it has regular DOHC injectors though right???