hesitation / fuel surge

Hi folks

had this problem a good while ago and couldnt seem to find the issue, replaced fuel pump, filter, plugs, leads, dizzy, maf, fuel pipes etc, some boost leaks were fixed, well it went away and now its returned

when driving at light throttle and accellarate i get a real bad hesitation, sort of feels like a bad fuel surge.

little video which you can kinda hear the issue although its usually worse than this with jerking and major power loss, funnily enough it wasnt wanting to do it when i had the camera on grrr

https://vid72.photobucket.com/albums/i194/FazeMDMA/Mobile%20Uploads/VIDEO0014_zpsavybhkwj.mp4

any help is much appreciated on where to try and pinpoint this issue

Sye

Hi mate, have you checked the timing on the car? I know it seemed to have gone away but has come back so may not be but might be worth doing that just to tick the box off.

Also have you got a dump valve? might be worth taking it off and plugging the hole to see if that helps.

I also have some hesitation on mine but I have HKS cams that we think have been ill fitted causing the car to behave very sluggish and loose power.

yeah ive got an apexi dv on it, ill remove it tonight and see if that causes the issue, wont timing affect idle etc too?

i dont have a timing gun to check the timing out

Check fault codes.
By a timing gun with your halfords discount,
Have a good hunt round for pipe leaks,
check/adjust TPS,
check fuel pressure & regulator function.

fault codes come back with nothing, det sensor has been happening lately but doesnt seem to be tied to the issue, ill get a timing gun this weekend, dont know how i test fuel pressure or regulator function? this was checked when the fuel pump was fitted and was deemed good for more boost.

how do i adjust the tps?

^ http://www.plmsdevelopments.com/sr_setup_tips.shtml#2.tps%3Cbr%3E

Number 2 in list for basic outline on TPS

here's the above info viewable & downloadable in a PDF for easy reference >
https://drive.google.com/file/d/0B7Ub2apq5-pfVHBRdW5ZbnJBU1U/view?usp=sharing

would my avcr show any signs of issues? the avcr i noticed does sometimes sit with the throttle at 1% when sitting idle and injector percentage i have seen spike occassionally to 70%-90% etc (could be total irrelevant) but my injector percentages range daily from 9% to 14%

thank you for the guide i will look into it more tonight, seems like very good info and the tps made me think about the avcr's readings

Hi could try doing a compression test for good measure whilst replacing the plugs?
Just a thought.
Also a mate of mine had a similar issue with det sensor and once it was replaced all was well.
Thought it may help!

^ yeh det sensor could be likely as at this age they likely far from suitable function.
Worth check det sensor wiring & clean plugs with contact spray, also using mutlimeter to check pins & actual sensor resistance to service spec would be wise.
New Blueprint sensor ADN17210 around £90 if lucky,£120+ if not.
Genuine knock sensor from USA (eBay) is under £40 > http://www.ebay.co.uk/itm/NISSAN-INIFINITI-MERCURY-GENUINE-KNOCK-SENSOR-22060-30P00-NEW-OE-/370824881563?hash=item5656e2a59b
To be honest I would class the DET sensor as a 20year service item & bang a new one on. They are super common for problems even at 10 to 15years of use.
Odd reading on avcr could be related to ecu blipping to safe mode if intermittent error such as iffy det sensor is triggering it ...

thanks guys im gonna order a det sensor and also a tps sensor for piece of mind and hope it sorts it.

where is the tps sensor located?

^ Think I would just grab a knock sensor first as that US price is decent & it one sensor that best renewed anyway really. I always fit new on any rebuilds I do.
would be wise test/set TPS & base timing & see where that takes you.
GTiR TPS is specific for the R.
Link below is online service manual for TPS location/basic image.
If you toggle through the pages you will see test procedure for TPS
http://www.gtirworkshopmanual.com/default.aspx?v=825
http://www.gtirworkshopmanual.com/default.aspx?v=826


@Sy Is a guide on here for TPS & Bob had some good coments on setting timing & Knock Sensor basic tests but hard find at present as the sites search is useless, google search was ok but don't seem be indexing via google any more as even direct searching from google for known content phrases never pulls a hit for gtir-mc ! needs fixing or far better inbuilt search ...

ok thanks guys ill order the det sensor and a timing gun and see if that helps

So i done fault code checks on the way home and everything was 55 even when the issue is happening so can the det sensor be at fault and not throw a code?

Seems to do it on bumpy roads also so maybe leading me to a loose connection somewhere.

Wher is your battery ?

Just under bonnet standard place i think

Digitalfaze wrote:So i done fault code checks on the way home and everything was 55 even when the issue is happening so can the det sensor be at fault and not throw a code?

Seems to do it on bumpy roads also so maybe leading me to a loose connection somewhere.

Could be loose connection ! worth checking & cleaning all sensor plugs (contact spray) & earths/cables etc.
I seem to remember you having some history of knock sensor code coming up ! would be good to give the sensor a good check & the plug & harness feeding to it.
What about your fuel pump wiring could connection or relay be less than perfect on that thus voltage fluctuates  when on bumpy road resulting in fuel pressure dropping ! I remember pump rewiring was not the best :-/

yeah gonna give this a try and clean everything i can find, i need to find a new battery terminal also as i couldnt get one small enough to fit the actual battery :/

the pump wiring was actually tidy the issue was the terminal which was knackered, i had to kind of bodge it up to get it to secure to the battery properly, this could be the issue though so ill need to source a small enough terminal

^ you have the original tiny battery with tiny terminals ! worth throwing that in bin & getting slightly bigger battery with standard size terminals, then fit quality terminals & solder them in with industrial solder iron or small flame torch.
Being intermittent it does point more likely to connection issue as normally a poor sensor would get worse or more constant fault, fingers crossed you sort it easily.
Still worth checking TPS, knock, Timing etc in depth as if not been done in years it should be really for optimisation/safety & covering the basics.

the battery was actually a new battery around 3 years ago, its what the computer said was for my car, timing and everything was all checked when fuel pump was fitted but ive ordered a timing gun so will be checking that out aswell.

so onto small terminals are these still available to buy? i assume if they sell the batteries then the terminals should also be available???

^ Yes you are correct, those small terminal batteries are standard correct type (same as on Micra)
It harder finding the smaller terminals but if you hunt around you should find some.
I always change to bigger terminals as easier & bigger range of batteries available off shelf.
What you can do is use terminal adaptor sleeves on your current battery so can use the standard bigger EU style clamps (link at bottom>), that way you have bigger choice in future on battery option/spec & price, also it easy to buy very decent quality clamps for the standard EU size ...
http://www.ebay.co.uk/itm/BRAND-NEW-JAPANESE-CAR-BATTERY-TERMINAL-POST-ADAPTOR-SLEEVES-1-X-POS-1-X-NEG-/301592423397?pt=LH_DefaultDomain_3&hash=item46384f2be5

The Japanese tractors we sell have the silly size battery terminals with those adaptors on, shame your not closer as I have a few sets

Digitalfaze wrote:Just under bonnet standard place i think

what about the connector block wher standard battery lead joins the plug conector can sometimes become faulty

Well ive been reading up on how to use this multithingymabobmeter and testing the earths, i unplugged my maf connector and tested the ohms on the middle pin (only pin that was giving a reading) i was getting 0.009, all other earth points were giving a 0.005 reading, is this correct or am i doing it wrong?

Thanks johnny ill check the out aswell, i managed to get a new terminal also

seems like checking all the earths and cleaning them, new terminal has helped the issue, still a slight hesitation but not near as bad, tps sensor seemed in really good condition. going to try my dump valve next, when blocking it off do i block both pipes off?