Strangeness at half throttle - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

93sr20240 · 09-02-2009, 03:14 PM

well put car back together after recently painting and ran perfect but went to drive 3 days after car had no problems and.... I start the car and idle goes up and down consitantly and pegs my wideband 10.0 rich..... well after alot of investigating found out a board inside my ecu came unplugged

well i plugged it back up started the car back and it acted normal went to take it down the road to see if all was fine and now if i give it more than about half throttle it bucks like you let in and out of the gas... its pulling boost fine... and seems to be not very noticable and cool temp but then gets worst when gets warm.... have been working on for about a week now and cant find the problem.... any help is appreciated

SoguRacing · 09-02-2009, 03:24 PM

check tps voltage and for vacuum leaks. specs are the fsm for the tps voltage

93sr20240 · 09-02-2009, 04:37 PM

voltage is 4.08 wide open and .47 closed

....can anyone tell me what the board is thats in my ecu.... I have not had the car tunned was thinking it looked like tune chips. but dont know

4x4le · 09-03-2009, 09:30 PM

Where at in tennessee are you? We can move the jumper to make your car run off the factory tune if your running stock injectors and stock maf (or we can do more)

Anyways, yes that is an aftermarket board. How long did you expose that board to sunlight? You could have started erasing the tune, sunlight erases the memory off of them chips, that is what the little windows on them are for......

93sr20240 · 09-04-2009, 07:16 AM

rogersville TN near bristol.... the ecu has always been closed just the board had came unplugged while going down the road and since I plugged it back up it hasnt been right. I have a wide band everytime it cuts out it pegs 10.0 rich

4x4le · 09-04-2009, 11:31 PM

sounds like a boost leak really, that or dirty maf. Your closed throttle voltage is a little high too.

93sr20240 · 09-07-2009, 06:49 PM

well thought I had it fixed but was not the case.... it is like its blowing the spark out or boost leak... its definatly is getting the fuel cause my wide band..... my plugs are gapped at .030 any other ideas runs drives fine but can control the point where it messes up with my foot....

93sr20240 · 09-07-2009, 07:06 PM

also im only seeing code 55 from ecu

98s14inaz · 09-07-2009, 07:55 PM

Quote:

Originally Posted by 93sr20240

also im only seeing code 55 from ecu

iirc that means all is well.

93sr20240 · 09-08-2009, 06:24 AM

Quote:

Originally Posted by 98s14inaz

iirc that means all is well.

yes.... still cant find why the car is acting the way it is

4x4le · 09-10-2009, 09:42 PM

I dont know that much about your specific engine but .30 seems a little much on the gap. Im running .26 on my sr.

Also if your running that rich you can have too much fuel making it hesitate.

Gap your plugs down and build a boost leak tester.

93sr20240 · 09-11-2009, 09:54 PM

thanks for the help ill try that tommorrow I got my fuel filter (z32) off and blew it out didnt seem dirty opened the ecu back up took board out plugged back in went and tried it it cleared up the first time i layed into it wich has done that before but then started acting up again.... it dont act the same way everytime but I will try and gap my plugs smaller and see if it helps im running bkr7e plugs a to4e top mount turbo runing 15lbs and before it was acting up my afr was 11.5-11.8 thanks for the help

09-02-2009, 03:14 PM	#1
93sr20240 Leaky Injector Join Date: Apr 2006 Location: Tennesse Posts: 79 Trader Rating: (1) Feedback Score: 1 reviews	Strangeness at half throttle well put car back together after recently painting and ran perfect but went to drive 3 days after car had no problems and.... I start the car and idle goes up and down consitantly and pegs my wideband 10.0 rich..... well after alot of investigating found out a board inside my ecu came unplugged well i plugged it back up started the car back and it acted normal went to take it down the road to see if all was fine and now if i give it more than about half throttle it bucks like you let in and out of the gas... its pulling boost fine... and seems to be not very noticable and cool temp but then gets worst when gets warm.... have been working on for about a week now and cant find the problem.... any help is appreciated

09-02-2009, 03:24 PM	#2
SoguRacing Post Whore! Join Date: Nov 2007 Location: (714) Age: 39 Posts: 2,967 Trader Rating: (23) Rides Gallery: SoguRacing Feedback Score: 23 reviews	check tps voltage and for vacuum leaks. specs are the fsm for the tps voltage __________________ Pre Tune Checkup! Compression,LeakDown,Vacuum Test $80. Cams Install: $180

09-02-2009, 04:37 PM	#3
93sr20240 Leaky Injector Join Date: Apr 2006 Location: Tennesse Posts: 79 Trader Rating: (1) Feedback Score: 1 reviews	voltage is 4.08 wide open and .47 closed ....can anyone tell me what the board is thats in my ecu.... I have not had the car tunned was thinking it looked like tune chips. but dont know

09-03-2009, 09:30 PM	#4
4x4le Zilvia FREAK! Join Date: Nov 2008 Location: Manchester, Tn Posts: 1,253 Trader Rating: (1) Feedback Score: 1 reviews	Where at in tennessee are you? We can move the jumper to make your car run off the factory tune if your running stock injectors and stock maf (or we can do more) Anyways, yes that is an aftermarket board. How long did you expose that board to sunlight? You could have started erasing the tune, sunlight erases the memory off of them chips, that is what the little windows on them are for......

09-04-2009, 07:16 AM	#5
93sr20240 Leaky Injector Join Date: Apr 2006 Location: Tennesse Posts: 79 Trader Rating: (1) Feedback Score: 1 reviews	rogersville TN near bristol.... the ecu has always been closed just the board had came unplugged while going down the road and since I plugged it back up it hasnt been right. I have a wide band everytime it cuts out it pegs 10.0 rich

09-04-2009, 11:31 PM	#6
4x4le Zilvia FREAK! Join Date: Nov 2008 Location: Manchester, Tn Posts: 1,253 Trader Rating: (1) Feedback Score: 1 reviews	sounds like a boost leak really, that or dirty maf. Your closed throttle voltage is a little high too.

09-07-2009, 06:49 PM	#7
93sr20240 Leaky Injector Join Date: Apr 2006 Location: Tennesse Posts: 79 Trader Rating: (1) Feedback Score: 1 reviews	well thought I had it fixed but was not the case.... it is like its blowing the spark out or boost leak... its definatly is getting the fuel cause my wide band..... my plugs are gapped at .030 any other ideas runs drives fine but can control the point where it messes up with my foot....

09-07-2009, 07:06 PM	#8
93sr20240 Leaky Injector Join Date: Apr 2006 Location: Tennesse Posts: 79 Trader Rating: (1) Feedback Score: 1 reviews	also im only seeing code 55 from ecu

09-10-2009, 09:42 PM	#11
4x4le Zilvia FREAK! Join Date: Nov 2008 Location: Manchester, Tn Posts: 1,253 Trader Rating: (1) Feedback Score: 1 reviews	I dont know that much about your specific engine but .30 seems a little much on the gap. Im running .26 on my sr. Also if your running that rich you can have too much fuel making it hesitate. Gap your plugs down and build a boost leak tester.

09-11-2009, 09:54 PM	#12
93sr20240 Leaky Injector Join Date: Apr 2006 Location: Tennesse Posts: 79 Trader Rating: (1) Feedback Score: 1 reviews	thanks for the help ill try that tommorrow I got my fuel filter (z32) off and blew it out didnt seem dirty opened the ecu back up took board out plugged back in went and tried it it cleared up the first time i layed into it wich has done that before but then started acting up again.... it dont act the same way everytime but I will try and gap my plugs smaller and see if it helps im running bkr7e plugs a to4e top mount turbo runing 15lbs and before it was acting up my afr was 11.5-11.8 thanks for the help