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Odd Misfire

Paulpen

By Paulpen,
in Engines & Forced Induction

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Paulpen Contributor

Paulpen

Posted
Posted

Seeing as there is a great deal of knowledge on here I may get some fresh ideas ;)

Ever since fitting my FMIC ive been having missfire issues.

Originally I gapped my plugs down a bit and seemed to make it a bit better so though it was coil packs playing up so went to new plugs and a wasted spark kit.

Went out today for a long run to see when it does it so here goes :

Idle is fine

Low rpm is worst but no proble if very light throttle

Mid range is almost ok but full throttle causes a slight misfire vibration

High rpm is the best but can still tell its there slightly on full throttle

Here are my rr graphs on another topic :

Graphs

That was done with the FMIC fitted. The only thing that has been changed since those graphs is the wasted spark kit and plugs.

Is it possible the overfuelling is causing the issue ?

:P:D

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Guilt-Toy Grand Master

Guilt-Toy

Posted
Posted

Okay Mate.. i just installed my new 7" TFT Touch screen in my car and i am in a good mood so here is my input.....

Your car is hitting R&R.. This is called Rich & Retarded.. This is a mode the ECU goes in when it detects that the engine is getting more air then it would in stock form. So the ECU takes out about 10 to 15deg of timing and adds about 40% extra fuel.

This causes the car to run like absolute shit. Nissan did not want people buying their skylines and turning the boostup, thrashing the f**k out of them and then blowing them up and returning them back to standard and claiming waranty.

Now this has worked, it made it VERY hard to turn the boost up and do mods to the car without changing the ecu, this is why the Apexi Power FC was introduced, to overcome these issues.

Your car has hit a brick wall, there is nothing you can do to fix it untill you buy a aftermarket ECU or use a rubbish bandaid fix like a signal bender (the nissan gods would cast a curse on you for going to the darkside if you do this)

To keep the Nissan gods happy, you should purchase a Power FC and get it tuned and this problem will go away and you will achieve the power curve that i have shown in this pic.

Hope this helps, sorry to say but there is NO way around this appart from the solution I have given you.

PS, PM me if you want to buy a power fc for $700USD :P

good luck with it.

Diagbyguilttoy.JPG

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Paulpen Contributor

Paulpen

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Posted

Thankyou for the informative post :D

Its nice to see something like that after have 2 topics here in the UK which are both 3 pages long ;)

Is there anyway that a FPR could help my situation before going to mapping ?

And also how would an EBC help my situation with the boost curve ? Or did you mean a boost controller in general to up it a bit ?

Ta again :P

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Guilt-Toy Grand Master

Guilt-Toy

Posted
Posted
Thankyou for the informative post :D

Its nice to see something like that after have 2 topics here in the UK which are both 3 pages long ;)

Is there anyway that a FPR could help my situation before going to mapping ?

And also how would an EBC help my situation with the boost curve ? Or did you mean a boost controller in general to up it a bit ?

Ta again :P

No problemo's.

No. Fuel pressure regulator will do nothing but cause you to pull out more hair then you have so far.

The EBC will help you have a flatter boost curve, instead of it spiking up all the way to redline it will hold the same boost from 3000rpm to 7000rpm.

Honestly mate, there is no way around this. I pulled my hair out back in 2004 with R&R issues and i know it is sooo frustrating. I was shamed at dyno days only making 198hp at the wheels because of R&R and I really had no money to buy a power fc so i tried and tried and tried. I ended up finding a way to make some money and buying a power FC and fixing the problem.

Seriously, buy yourself a power fc. You will not regret it. The difference as one guy told me after installing a power fc and tuning it in his car "it was like jumping out of a 3 cyl car and jumping into a powerfull V8"

You have no idea how alive your car will be once you get your power fc installed and tuned properly... I have tuned many of these cars and get a kick of out it when the owners come back from their test drive with a massive smile on their face.

it really makes a massive difference.. You should try and save up the money and buy the ECU upgrade and get it tuned properly because the difference it will make to your car is just un believable.

*goes off to get another drink* ;)

back from drink, and drunk it.. here is where R&R is hitting in and where your AFR curve should be once tuned properly with a Power FC.

randr.JPG

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tridentt150v Grand Master

tridentt150v

Posted
Posted

emanage will do it, but a power fc will do it better, you get what you pay for.

Alternatives to the power fc are available [haltech, vipec, link, autronic, motec, etc etc] and they all have their good and bad points, but the power fc is the simplest best known genuine plug and play solution, it will slot into your system and work straight away [with a tune up of cause].

ohh and it has the most support and is the best known - and Guilt Toy knows his skylines inside out so listen to him.

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Paulpen Contributor

Paulpen

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Hmmmmm interesting !

Haltech, vipec, links, autronic and motec are very rarely used over here so finding someone capable of using them could be an issue !

The main things used over here are Power fc and emanage.

Some less used things inclue Link, f-con and omex.

There is also a tuner that does a stage 1 chip

RSP Stage 1 ECU Upgrade to run the following mods.

Full exhaust system

Induction

Front Mount Intercooler

Boost increase upto .85b

Bear in mind I know nothing about any of the systems ivel isted other than the names :P

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Paulpen Contributor

Paulpen

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emanage will be fine for your application mate.

Good luck with it! please post some pics of your car.. just like seeing pics of skylines overseas etc etc.

cheers

Looks like ill be saving up for ultimate then if it works with my wasted spark setup.

Its not really a skyline though.................................. :)

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