GSR 4G93 misfire...or hesitation

[BMGTZ]

The GSR I gave to my daughter is possibly the slowest example of one of these cars I have ever driven. I have three with the 4G93...one is chipped and big exhaust etc etc...the other has 245,000k and is a virgin. But easily outpowers the daughters car which is also a virgin and has 183,000km.

the car has a an annoying sort of hesitation...powers then for a half second stutters then goes and does it again. it is there hot and cold and it is there right up through the rev range.

Ive done the following to try to solve it.these parts were swaped with another car that had, and still has no problems.
-replaced injectors with cleaned and flowed set.
-exhaust and cat changed.
-front part of std exhaust is undamaged
-ignitor
-coils
-new plugs
-leads
-air flow meter
-fuel filter
-Ive looked at the ecu and whilst it is standard unchipped ecu there are no visible signs of damage and the part number is correct
-the car still makes and holds factory boost

I know the guys at the dealer ship it has been serviced at since new....the service history show a few reports of low power and poor acceleration.

my next port of call will be a fuel pump????

suggestions are welcome.

I dont have a data logger but would like to buy one...can someone suggest what I need in that respect.

 

[Kane_GSR]

my next port of call will be a fuel pump????

My mate has a 180sx with Sr20det. He was lacking power once on boost and turned out to be his fuel pump not supplying enough pressure.

Too check pressure, where the hose joins the rail, with the car off and let rest overnight you should be able to squish the fuel line together. Once the reds are on and or the car idling, you shouldnt be able to as there should be pressure.

Another thing I would check would be water temp sensor (ecu sendor unit) and the o2 sensor..

 

[GSR94T]

while i agree with possible fuel pump being the issue, your best option is a datalogger. this will tell you if enough fuel is being supplied with simple plug and play.. and at the same time you wont be spending money on parts which may not be faulty

as for a datalogger, you'll need a cable made up to suit the ecu port, as well as MMCD software on a palm pilot (all from memory) - the other guys on here will know more about that stuff than me

further to this id get the timing checked

 

[GSRWRC]

What are the plugs gapped to?

 

[Richard]

Get the fuel pump flow tested, it may make enough pressure at idle but you need to see what pressure and flow rate it has at full duty cycle and on boost. fair chance that is your issue.

 

[BMGTZ]

Get the fuel pump flow tested, it may make enough pressure at idle but you need to see what pressure and flow rate it has at full duty cycle and on boost. fair chance that is your issue.

I think I will just throw a new one in ....and then the old one at it!!

 

[BMGTZ]

what are the plugs gapped to?

.7 - .8

 

[Liberoz]

The GSR I gave to my daughter is possibly the slowest example of one of these cars I have ever driven. I have three with the 4G93...one is chipped and big exhaust etc etc...the other has 245,000k and is a virgin. But easily outpowers the daughters car which is also a virgin and has 183,000km.

the car has a an annoying sort of hesitation...powers then for a half second stutters then goes and does it again. it is there hot and cold and it is there right up through the rev range.

Ive done the following to try to solve it.these parts were swaped with another car that had, and still has no problems.
-replaced injectors with cleaned and flowed set.
-exhaust and cat changed.
-front part of std exhaust is undamaged
-ignitor
-coils
-new plugs
-leads
-air flow meter
-fuel filter
-Ive looked at the ecu and whilst it is standard unchipped ecu there are no visible signs of damage and the part number is correct
-the car still makes and holds factory boost

I know the guys at the dealer ship it has been serviced at since new....the service history show a few reports of low power and poor acceleration.

my next port of call will be a fuel pump????

suggestions are welcome.

I dont have a data logger but would like to buy one...can someone suggest what I need in that respect.

Looking at everything above I've noticed that you havent checked the timing!
Simpler things have caught others out before

 

[BMGTZ]

Looking at everything above I've noticed that you havent checked the timing!
Simpler things have caught others out before

thanks for the replies guys.....this thing is proving to be a challenge. I will check the timing ....may have done this when I asked a question about the timing plug position a while back....but not 100% sure

can any one suggest a good place to start for the data logger?

 

[GSR94T]

http://meek.com.au/index.php?v=Product&id=74&pcid=29

$93 for cable and software

then you need a palm

 

[BMGTZ]

http://meek.com.au/index.php?v=Product&id=74&pcid=29

$93 for cable and software

then you need a palm

thanks mate need some other stuff from them too ....so will get it all together

 

[rob323]

Can't hurt to pressure test the intake in case you have a boost leak somewhere causing it to run rich.