Rolling Road

[Wyn]

Atlast I've pulled me finger out and booked my RB 260z into a rolling road tomo to have it remapped.
Fed up with it pottering about at part throttle so time boost me up large

Anything up n over 350 will be a bonus
Anything less will mean certain death

If all goes well it should be an interesting drive back

[Mr.G]

Sounds good Wyn, that will make all the difference.

What ECU did you end up with and who is doing the mapping for you?

[Wyn]

George
Its using an Apexi power fc which I bought used some time back.
I set it to its base map just so I could use the car
Since i've had it on the rd its been running ok, but its always needed sorting to get it up to full power
Taking it to Horsham developments nr Newbury

[Wyn]

Originally Posted by 900ss

Anything less will mean certain death

If all goes well it should be an interesting drive back

Out with the baseball bat Piece of ****

Ended up at 301 but now with a bad misfire on boost

Now need to go chasing me tail to see whats causing the prob
Could be coils, plugs or other ... More money !!

[Mr.G]

Wyn,

Bummer not what you wanted to learn but at least the rolling road made any issue easy to spot.

Don't rule out the charging system, I was getting a misfire which was down to an alternator issue, my ecu wasn't getting a full 12V which was causing strange behaviour including misfiring on boost like you.

Also, having the incorrect plug grade will make a difference, which I've also witnessed recently.

Good luck!

[Wyn]

Just tried a brand new set of plugs but still the same so that rules those out
Did notice the old plugs 5 - 6 looked black unlike 1 - 4 which have whitened centres?
Should have a few spare coils and ignitor so will try those next
btw, car cranks very strong and starts fine aswell as showing 14v + so cant see it being a charging issue

[jonbills]

I'm guessing, but the plug conditions are significant I think. the map will be set based on lambda sensor in the exhaust, which averages all cylinders. so it sounds like you've got 2 cylinders significantly overfuelling, which leads to 4 being lean when the average lambda is correct.
so... I'd be swapping the injectors around to see if the fouling follows them.
or looking at fuel pumps - is there only one pump or multiples?

[jonbills]

and obviously 4 lean ones would explain the misfire on boost.

[Wyn]

I'm thinking its igntion atm ?
Could it not be the black plugs are from the cylinders with the misfire or the other way around
But as injectors are easy to change I can try swapping those about aswell to see if the plugs change colour

[jonbills]

yes, I guess that could be the case too :-) - do those two cylinders share a coil pack? but if the plugs of the other 4 are bright white, they are too lean.
I think swapping the injectors around will at least confirm quickly if there's a problem with them or not.

[Wyn]

It uses 6 seperate uprated coils
I have a few spares so will try swap a few parts about today

[Rob Gaskin]

Wyn, can't you get the engine management diagnosed by the rolling road operators?

Did they just take a power run or was it 'hooked-up' to diagnostic equipment. Years ago when I had my 240 on a rolling road it was 'tuned' whilst on the rollers to get the best result. My 240 of course was a lot simpler but it came away running faster and smoother not worse like yours!

[Wyn]

To be fair the car was in for injectors/ air flow meter and then to be remapped once they had been fitted. It wasn't untill they had been fitted and the boost turned up that the problem showed.
No the car wasn't in for diagnostics as such so unless they changed plugs, coils or diffo injectors etc they wouldn't have found the issue
That is my problem, but i'll get there

[datsun dave]

Originally Posted by 900ss

Out with the baseball bat Piece of ****

Ended up at 301 but now with a bad misfire on boost

Now need to go chasing me tail to see whats causing the prob
Could be coils, plugs or other ... More money !!

Welcome to my world !!!!

[tel240z]

just a long shot Wyn but we had a misfire problem with Darrens car, tracked it down to the CAS rb26 cam sensor | eBay

His got worse over a period of time