Flat Acceleration

[tmc_2]

Hi Guys, aftyer 5 weeks of searching this forum trying to diagnose my problems wiht my r33 i am now at the last resort and need to ask u guys for your opinion.

The car drives fine idles fine but if i accelerate anyhtign more than say 1/3 throttle and it gets a noticable flat spot majorly. Its so flat it rev out slow. VR commodores beat me!! This is my second r33. It does not misfire or splutter at all, just does not rev out like ti should. Turbo is boosting and spooling like it should be.

I have stock intercooler has bleed valve but i returned it back to stock 7 psi boost.

Turbo back exhaust, pod filter, GFB BOV set to plumb back, JustSR metal intake pipe.

apparentl rebuilt wiht forged acl pistons so the previous owner claims.

Now to try and fix this problem i have done the following.

1- Installed hard metal intake pipe to prevent any loos of power due to the rubber pipe sucking closed.

2- Made sure there are no boost leaks or vacum leakes.

3- Installed another Air flow meter which noticably looks to be in better condition.

4- Walbro high flow fuel pump ( the claimed 500hp jobbies )

5- Replaced the fuel filter

I am to the point that if i cant fix it soon i am thinking of selling it.

If any one has any idea please let me know, if u live in brisbane ill even pay you if u can make it better!

Thanks inadvanve guys

Edited December 22, 2006 by tmc_2

[MANWHORE]

Man, that's tricky because you've done so many mods at once. My rule is do one at a time so that you know which one causes problems.

I reckon rich and retard, or high rpm misfire due to coil or spark related issue.

[tmc_2]

Man, that's tricky because you've done so many mods at once. My rule is do one at a time so that you know which one causes problems.

I reckon rich and retard, or high rpm misfire due to coil or spark related issue.

Yeah it is trucky, i Didnt do all the mods at once, the list i have down is each thing i did one by one to try and fix the problems it was having, after each thing i did the car still had the problem , i did each step about 5 days apart.

Correct me if i am wrong but - If this is a spark related problem the car should splutter or misfire? i dont have any of those symptoms?

If it is rich and retard why is it going it on standar 7psi boost? I have a SAFC Neo comming for it so f i cant fix it in the next few weeks ill leave it in the hands of the tuners when they install the safc.

If any one has any ideas id much appreciate the input. Cheers

[tmc_2]

hey guys today i changed my plugs to see if that would help. I put in NGK BCPR6ES 0.8mm gap

This didnt fic the problem at all???

"Old plugs came out with what looked liek oit around the washers and very black with carbon build up. all 6 plugs where in the same condition.

Any ideas on waht is casueing this massive hesitation?

[SilverECR33]

so it moves, then has huge flatspot, then when revs pick up, its got some power but not as much as it should?

Could be a few things,

ignTiming, Cam timing, ECU map.

I had a similar problem with my v8, and it was the cam timing. But i mean, i could be wayyyyy off, we are talking about 2 different engines

id say take it to, all star performance(richard), or Xtreme Automotive(paul) on Compton road. let them drive it and see what they think,

Edited December 24, 2006 by silverbulletR33

[MANWHORE]

I was thinking either misfire or rich and retard.

If it's not misfire from spark related issues, then I woulda thought rich and retard (when the ecu sees too much airflow), but you're only running 7psi boost. Is it definitely 7psi boost (not insulting your intelligence, but you're not looking at the +7 on the stock guage are you?).

As silver was saying, have you checked the timing with a light?

Cheers

Edited December 24, 2006 by MANWHORE

[MANWHORE]

Also, maybe take the cover off your ecu, and see whethe rit's a chipped jap one. the map might be totally wrong for australian fuel.

Does it feel like it's running very low timing, like have you felt rich and retard before? does it feel like that?

Also, have you ran an error check for fault codes on ecu?

[MANWHORE]

If only you were in sydney, i'd be able to help you out.

I've had a couple friends with issues like yours, and basically, we just ran through checking all of the usual culprits, and eventually it was fixed.

[tmc_2]

If only you were in sydney, i'd be able to help you out.

I've had a couple friends with issues like yours, and basically, we just ran through checking all of the usual culprits, and eventually it was fixed.

Thanks for the ideas guys,

According to my HKS boost guage its reading just under 0.5 bar so i think about 7psi.

i dont think its spark related as it doesnt break down and splutter or misfire. I thought it was rich and retard but on stock boost? apparently it can be rich and retard on the rare occasion with stock boost.

Ill think ill take it into a work shop after xmas if i cant figure it out my self.

If any ones has any ideaqs what to check that would be great

Cheers.

[tmc_2]

Also, maybe take the cover off your ecu, and see whethe rit's a chipped jap one. the map might be totally wrong for australian fuel.

Does it feel like it's running very low timing, like have you felt rich and retard before? does it feel like that?

Also, have you ran an error check for fault codes on ecu?

Oh by the way i checked the ecu it is a stock one from what i can tell externally. I have not been able to check the actual base timming yet as i dont have a timming light.

[tmc_2]

Hey guys could it be some thing to do with the knock sensors? wha tis they are faulty or not reading right? will that casue the car to go into some sort of rich and retard or limp mode while on stock boost?

[MANWHORE]

Only one way to find out. If you have consult, run it and check.

If not, run the diagnostic process, and see what fault code it brings up using by flashing the check engine light.

[tmc_2]

Only one way to find out. If you have consult, run it and check.

If not, run the diagnostic process, and see what fault code it brings up using by flashing the check engine light.

Ok latest update,

I ran the diagnostic mode, i got 5 slow then 5 fast flashes so that means all sensors are working fine.

I also went ahead and installed a FMIC kit that i knowing that would do nothing to fix my problems but i was sick of looking at it in the box.

Car is still experiencing same problem on stock boost. Has any one experienced this problem and have any ideas on how to fix it?

[wilch]

Getting a timing gun and check your base timing...

Should be 14degrees BTDC if I recall correctly. I reckon it'll be retarded. If it is, this'll be the problem.

[tmc_2]

Getting a timing gun and check your base timing...

Should be 14degrees BTDC if I recall correctly. I reckon it'll be retarded. If it is, this'll be the problem.

Hi guys

I go thte timming checked and set to 15degres base timming.

It is marginally better off the line but still has the same problem when any load or acceleration is applied. No poping or misfire noises.

when the work shops open in the new year i will drop it in to get checked, i also have a SAFC neo but i havent installed that yet as i am trying to fix its shit drivability.

[Wheezy]

You said you have a "supposed" walbrow pump....put the stockie back in and see what it does, couldnt hurt to try, failing that try another timing light, and make sure it really is 15deg.

[tmc_2]

You said you have a "supposed" walbrow pump....put the stockie back in and see what it does, couldnt hurt to try, failing that try another timing light, and make sure it really is 15deg.

Hey Wheezy, I had the problems first then i installed the walbro pump thinking that the problems where because of my stock original pump. The walbro i bought was from KUDOS motorsport, the pump casing case the walbro engraving on it so i assume its legit.

I did all hte mods listed after i was experiencing running issues.

[tmc_2]

Update,

I resoldered the air flow meter but that didnt fix anyhting so i put the old one back it, it obvisouly isnt a faulty airflow meter??

[NYTSKY]

Yeah it is trucky, i Didnt do all the mods at once, the list i have down is each thing i did one by one to try and fix the problems it was having, after each thing i did the car still had the problem , i did each step about 5 days apart.

Correct me if i am wrong but - If this is a spark related problem the car should splutter or misfire? i dont have any of those symptoms?

If it is rich and retard why is it going it on standar 7psi boost? I have a SAFC Neo comming for it so f i cant fix it in the next few weeks ill leave it in the hands of the tuners when they install the safc.

If any one has any ideas id much appreciate the input. Cheers

Hi mate i have the same problem with mine.Half throttle is ok.But at full throttle it goes flat at 3000RPM up to 5000RPM then fine.Its at 9psi at the moment but tomorrow its going back down to 7psi.Im pretty sure its rich and retard mate.I never had this problem before i installed the pod and FMIC.The car is getting alot more airflow now.Im trying to chase a Power FC(needle in a haystack)but im sure that will sort it.

[tmc_2]

Hi mate i have the same problem with mine.Half throttle is ok.But at full throttle it goes flat at 3000RPM up to 5000RPM then fine.Its at 9psi at the moment but tomorrow its going back down to 7psi.Im pretty sure its rich and retard mate.I never had this problem before i installed the pod and FMIC.The car is getting alot more airflow now.Im trying to chase a Power FC(needle in a haystack)but im sure that will sort it.

Hey man, yeah i htought maybe rich and retard? but even on stock boost :S

I have a SAFC NEO comming but now think i should have spent the extra on a PFC>

I have a mate who offered to let me try his PFC to see if that sorts anyhting out, ill let u know how i go in a day or two after we have tried it.

The hesitation in mine is really sever, overtaking commodores is impposibble and imbarassing.