Huge stutter under load...Help!

[M0R81U5]

I suggested Fuel pump when I was at Meek last, but Chris seems to think it's ignition related. I changed the fuel filter a little while back.

Same here Steve, I just want to get some clue to what it is.

 

[JUSTCRUZN]

WTF!!!! just watch the vids thats weird as f**k... could it be injectors? or fuel regulator?

 

[naughtika]

more like ignition problems to me.. if its fuel related issue, your engine would be toasted by now and if not, your ecu would've have tried to dump sh!t loads of petrol.. which means your economy would be really crap..

 

[GavDaniels]

Hey There.

Do you ever get issues of the car not wanting to rev past 2500 RPM?
I had an issue with my fuel pump relay.

In these cars the fuel pump runs of around 8v at low revs, then it gets full volts as the car is on boost.
My fuel pump relay had fallen off the mounting bracket (held on only by the rubber gromet cover) and had filled with water and corroded.

My car would drive fine at times, then at others it would run only to 2500 RPM. trying to go above that it would die in the arse and try and stall.

Regards

Gavin

 

[TME_Steve]

It's like a pipe not conected looking at the video, makes boost, pipe falls off, dies, pipe joins up, makes boost etc, but the revs are too high, you've well and truly made boost by then I would have thought.... I bet it's something weird and stupid though, certainly an odd one. And doesn't look like a boost cut, it keeps coming back on too quick.

 

[98 SPORT]

Could be ECU related,swap it if you can borrow one and see, ive had this problem before with a Mitsi,i think that what the problem was,in the ignition triggering side of the board,it was a while ago.
If you have a laptop, ebay,item #300434229264, scantool and disc,has 4 diagnostic programmes on it,you can run live and it will map the fault,$22 its the best $ youll ever spend.
Always remember to make sure your ignition is off before plugging or unplugging a scantool.

 

[legnum600]

My car used to stutter under load, it turned out to be the throttle bodie elbow pipe poping off. i have since replaced with one of ivans silicone hose elbows.

 

[M0R81U5]

Christian: My fuel economy has dropped off over the past few months. Not massively, but it's definite;y noticeable.

Gav: Haven't had this one mate, it could always rev past 2500rpm.

Jason: That elbow has been replaced with one of Ivan's silicon jobs and the problem was there with both the standard plastic one and Ivan's silicon one.

Ray: I'll hopefully be logging the fault this week with the help of Steve (shtiv), so I'll let you know when we have some data

 

[TME_Steve]

So we had a look with evoscn and no DTC's (except the usual vehicle speed sensor) and doing a quick log we saw that the load drops and the fuel signal follows so the ECU looks like it's telling things to do the right stuff.... Definately not a fuel cut. We also dropped a different stock ROM on the ECU (mainly as it was an easy thing to do and rule out) and it still had the same problem....

Hearing it from outside it sounds like an ignition cut. And you'll never win any drags at the lights with it going like that.... Haha!

You can swap MAF's with me next time I am down that way to try but I bet that's not it also but it's certainly load related, as soon as you make a certain amount of power, bam, and it's full on, as severe as a boost cut but quicker coming back on....

 

[reeve]

steve try my setup and see if it pays off, or double insulate the leads, brand new leads can still arc

 

[M0R81U5]

Thanks again for today Steve, I'll hook you up with a case of your favourite beverage next time I see you

With that fresh map, the car drives far better (up til 5000rpm), so it must have pulled a shit-ton of timing out of it all through the rev range. Heh, you're right about dragging off the lights, I nearly got beat by a fully loaded diesel Landcruiser last night, I think I only got in front cause he was distracted by the jerking, bouncing wagon next to him

It would be good to swap your MAF if nothing else, just to rule out another part.

 

[king_panther]

On a side note Mick, have you thought of hiring out your wagon to single ladies so they can get off on the jerking?

lololololololololol !

 

[M0R81U5]

I don't really know how to reply to that Brad....nope, can't say I have thought of that

My 18mth old daughter finds it pretty entertaining, but I think she may just be laughing at me getting angry at the car

 

[TME_Steve]

I'll bring a stock BOV and you can swap my MAF's next time I'm there to rule them out.... Andrew, was your miss like cutting the engine completely? this is like 0 throttle, 100%, 0%, 100% etc I would have thought interference would be not so viscious.... Mick, does it happen in 4th and 5th too?

 

[M0R81U5]

Can't say for sure Steve. It will definitely do it in 3rd, but I've been too scared to push it to 4-5K rpm in 4th or 5th on public roads.

I still haven't had chance to check out the throttle body, but I'll let you know when I do

 

[M0R81U5]

So....the source of the problem has been found!!

Met up with Steve this arvo and as he suggested swapped the MAF from his car to mine and whaddya know....stutter gone, it was running beautifully, except for a small hesitation around 4.5-5K, but I'll worry about that later. Just gotta find a new MAF now.

Thanks again Steve, you're a special human

 

[VOLK]

HTH:

http://page21.auctions.yahoo.co.jp/jp/auction/j45070989

Email dartsun75 at gmail.com about acquiring it

 

[TME_Steve]

Awww thanks, just glad it's sorted....

 

[ZEUSvsHADES]

could you try cleaning it? there is i fair bit of info on the net about cleaning them...what do you have to lose?

 

[M0R81U5]

Yeah, true. To look at it, I can't see anything 'wrong' with it, I mean it doesn't look excessivley dirty. I will get another one regardless, but I may try and clean it just to see what happens.

Cheers for the link Joey, I'll look into it