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

Boostin240sx · 11-21-2007, 07:58 AM

I bought a 91' coupe with a blown motor and put in a KA from a 97'. I used the intake manifold, ignition and all that from the 91'. I did wind up having a broken injector and replaced it with one from the 97'. I think I've checked the timing about 6 times it may be only about a degree off.

It kind of stutters sometimes when it is cold in the 1800-2800 range. It also feels like there is no power above 3400 when it is warmed up and cold. It struggles to get to 80 mph.

My thoughts were I tore an injector seal putting in the new injector and at higher pressures it just robs the power or a vacuum leak.

Any help or other suggestions?

*DALAZ_68* · 11-21-2007, 08:17 AM

do have boggin issues at all... does it feel like ur cars leaning out at higher rpms

lemme put it this way... can u slam ur foot to the throttle and have instant response and speed up...or do u hit the throttle full and it bogs hesitates...etc

unicoladron · 11-21-2007, 09:02 AM

how was this 97 KA engine running before you swapped it in. i think it's wierd you're having hesitation problems since you've swapped a different injector in than the rest of the three. perhaps the injectors don't "match". do you have an un-even idle?

did you use new gaskets when swapping the intake manifold? it sounds like you're leaking lots of vacuum. do the carb cleaner trick. spray near your intake mani and see if it gets sucked in and/or see if your idle changes

Boostin240sx · 11-21-2007, 09:35 AM

If I am cruising and slam my foot on the throttle it doesn't necessarily bog down just has no power. The engine just slowly revs up and feels like it can barely make it to redline.

The KA was running great prior to pulling. It actually used to be KA-t in the 97' and made about 300 hp. It also compression tested fine prior to pulling.

It idles like a champ without any problems.

Unforntunatly I did not use a new gasket, the old one looked like it was in pretty good shape. The carb cleaner is definitely my next test.

aznpoopy · 11-21-2007, 09:42 AM

#1 use new gaskets

#2 get a timing gun and time it; edit: nvm you did it already. probably not your issue then

#3 regarding that injector, if you fucked up the seal it sprays fuel non stop into the motor since the rail is under pressure. that in turn will dilute your oil with gas (which is bad, since oil generally shouldn't have the consistency of water - you can see how this might be bad for metal on metal contact) and generally make your car run like ass. use new seals, install it properly

*DALAZ_68* · 11-21-2007, 09:43 AM

Quote:

Originally Posted by Boostin240sx

If I am cruising and slam my foot on the throttle it doesn't necessarily bog down just has no power. The engine just slowly revs up and feels like it can barely make it to redline.

The KA was running great prior to pulling. It actually used to be KA-t in the 97' and made about 300 hp. It also compression tested fine prior to pulling.

It idles like a champ without any problems.

Unforntunatly I did not use a new gasket, the old one looked like it was in pretty good shape. The carb cleaner is definitely my next test.

woah woah woah....the engine pulled 300hp...then its gotta be ur ECU...

if the engine is from a 97 OBDII car...and ur running the OBI harness...then uve lost the mapped out/tuned ECU for it cuz ur using a DOHC s13 harness and ECU right...?

also might wanna check the injectors again...they might not be the OEM ones

unicoladron · 11-21-2007, 10:00 AM

Quote:

Originally Posted by DALAZ_68

woah woah woah....the engine pulled 300hp...then its gotta be ur ECU...

if the engine is from a 97 OBDII car...and ur running the OBI harness...then uve lost the mapped out/tuned ECU for it cuz ur using a DOHC s13 harness and ECU right...?

also might wanna check the injectors again...they might not be the OEM ones

he only mentioned he's using the motor from the 97, it seems like he's using the harness and ecu from his 91. but there is no evidence supporting this?

which harness and ecu are you using?!

Boostin240sx · 11-21-2007, 10:09 AM

I'm using the 91' harness and ECU.

How would gas get in the oil if an injector seal was bad assuming all the other seals were good. If by chance it was squirting that much gas into the intake runner to blow by another seal then I imagine it would be running pig rich, smoke like crazy and not to mention smell it in the exhaust.

SidewayZ-s14 · 11-21-2007, 10:13 AM

I had the same problem with my KA before. Everything was fine reving my car but once i stepped on it a bit, it felt like it was hitting rev limiter right around 3500 rpm, and it sort of sputtered and would take a long time to get up to 5000. Well if it helps you at all, my problem was my fuel pump! It was bad. Might wanna check your fuel pump! I have one if you need one. Good luck!

*DALAZ_68* · 11-21-2007, 10:17 AM

Quote:

Originally Posted by unicoladron

he only mentioned he's using the motor from the 97, it seems like he's using the harness and ecu from his 91. but there is no evidence supporting this?

which harness and ecu are you using?!

thats why im asking what u just asked lol

cuz if thats the case its obvious what the situation is

11-21-2007, 07:58 AM	#1
Boostin240sx Leaky Injector Join Date: Jan 2006 Location: VA - 757 Posts: 134 Trader Rating: (2) Feedback Score: 2 reviews	KA24DE hesitation problems I bought a 91' coupe with a blown motor and put in a KA from a 97'. I used the intake manifold, ignition and all that from the 91'. I did wind up having a broken injector and replaced it with one from the 97'. I think I've checked the timing about 6 times it may be only about a degree off. It kind of stutters sometimes when it is cold in the 1800-2800 range. It also feels like there is no power above 3400 when it is warmed up and cold. It struggles to get to 80 mph. My thoughts were I tore an injector seal putting in the new injector and at higher pressures it just robs the power or a vacuum leak. Any help or other suggestions?

11-21-2007, 08:17 AM	#2
DALAZ_68 not giving a fuck Join Date: Apr 2007 Location: Los angeles Age: 38 Posts: 15,077 Trader Rating: (104) Feedback Score: 104 reviews	do have boggin issues at all... does it feel like ur cars leaning out at higher rpms lemme put it this way... can u slam ur foot to the throttle and have instant response and speed up...or do u hit the throttle full and it bogs hesitates...etc

11-21-2007, 09:02 AM	#3
unicoladron Zilvia Junkie Join Date: Jul 2007 Location: Long Island, NY Age: 40 Posts: 568 Trader Rating: (0) Feedback Score: 0 reviews	how was this 97 KA engine running before you swapped it in. i think it's wierd you're having hesitation problems since you've swapped a different injector in than the rest of the three. perhaps the injectors don't "match". do you have an un-even idle? did you use new gaskets when swapping the intake manifold? it sounds like you're leaking lots of vacuum. do the carb cleaner trick. spray near your intake mani and see if it gets sucked in and/or see if your idle changes __________________ 1993 KA24DE for sale with 180k..running when pulled.... need to get rid of ASAP...i'm moving

11-21-2007, 09:35 AM	#4
Boostin240sx Leaky Injector Join Date: Jan 2006 Location: VA - 757 Posts: 134 Trader Rating: (2) Feedback Score: 2 reviews	If I am cruising and slam my foot on the throttle it doesn't necessarily bog down just has no power. The engine just slowly revs up and feels like it can barely make it to redline. The KA was running great prior to pulling. It actually used to be KA-t in the 97' and made about 300 hp. It also compression tested fine prior to pulling. It idles like a champ without any problems. Unforntunatly I did not use a new gasket, the old one looked like it was in pretty good shape. The carb cleaner is definitely my next test.

11-21-2007, 09:42 AM	#5
aznpoopy Post Whore! Join Date: Mar 2003 Location: New Jersey Age: 44 Posts: 5,013 Trader Rating: (1) Feedback Score: 1 reviews	#1 use new gaskets #2 get a timing gun and time it; edit: nvm you did it already. probably not your issue then #3 regarding that injector, if you fucked up the seal it sprays fuel non stop into the motor since the rail is under pressure. that in turn will dilute your oil with gas (which is bad, since oil generally shouldn't have the consistency of water - you can see how this might be bad for metal on metal contact) and generally make your car run like ass. use new seals, install it properly

11-21-2007, 10:09 AM	#8
Boostin240sx Leaky Injector Join Date: Jan 2006 Location: VA - 757 Posts: 134 Trader Rating: (2) Feedback Score: 2 reviews	I'm using the 91' harness and ECU. How would gas get in the oil if an injector seal was bad assuming all the other seals were good. If by chance it was squirting that much gas into the intake runner to blow by another seal then I imagine it would be running pig rich, smoke like crazy and not to mention smell it in the exhaust.

11-21-2007, 10:13 AM	#9
SidewayZ-s14 BANNED Join Date: Nov 2007 Location: SoCal 714 Posts: 1,061 Trader Rating: (14) Feedback Score: 14 reviews	I had the same problem with my KA before. Everything was fine reving my car but once i stepped on it a bit, it felt like it was hitting rev limiter right around 3500 rpm, and it sort of sputtered and would take a long time to get up to 5000. Well if it helps you at all, my problem was my fuel pump! It was bad. Might wanna check your fuel pump! I have one if you need one. Good luck!