Boost / fuel problem

If it is an SDi then boost cut is the answer.

its a zr with sdi injectors. is the injector 1 cable ok? just something to check.....
what happens if you set boost to 18-19psi?? or is it just 19.5psi that it happens at?

Yeah it's a zr with sdi injectors. Well it seems below 19psi is ok. When I upgraded to different injectors the number 1 cable was cable tied together (before changing) then changed injectors and cable tied it together. Problems have been since changing injectors. I will clean out that plug tomorrow if I get a chance.

Thanks for the help guys

lol we havnt really done much lol. of you fancy a drive on the 16th oct you can come to our meet, check out the south forum

the cars are ecu limited in first gear to stop the gearbox being damaged

i thought the ecu limited fueling at about 2k rpm due to the torque spike that happens around there?
my R25 td with sdi injectors will go past 4k in 1st gear when hot every time.
never tried it cold as thats just asking for trouble.
i have not touched the ecu in mine at all.

edit: just been out in mine and with a warmed up engine i can easily shoot past 4k rpm in 1st gear.

boothy you said after a long test drive yours only has this 4k brick wall in 1st gear, did it have this wall in any other gears BEFORE the test drive?

well its doing it 8 out of 10 times in every gear now even when warm. Just want to get it sorted as i wanna start looking for a new car now. I would keep it but i fancy a change.
I have heard of this ECU limiting in first gear before but i know mine used to go all the way past 4k in first gear :S

pocketbikeuk said:

the cars are ecu limited in first gear to stop the gearbox being damaged

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1st and second. But you'll not notice the limit.

limited how exactly? fueling wise to avoid the torque spike at about 2k rpm??
as ive always managed to get mine to rev up to and past 4k rpm every time.
restricting the car to 4k rpm max to avoid damaging the gearbox seems a little odd as the peak torque is much lower than 4k rpm.

There are loads of types of torque limiters out there, but essentially a torque limiter is just a rule of how much fuel is permitted at a given engine speed. No more is allowed but less is okay. Sometimes they have other variables too, like ambient pressure for altitude compensation as one example but not in our case.

There are sometimes more than one torque limiter, and the one you use depends on the situation. If you think hard you'l probably be aware of another (limp mode anyone?).

mushymarlin said:

limited how exactly? fueling wise to avoid the torque spike at about 2k rpm??
as ive always managed to get mine to rev up to and past 4k rpm every time.
restricting the car to 4k rpm max to avoid damaging the gearbox seems a little odd as the peak torque is much lower than 4k rpm.

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The torque curve is lower in 1st and 2nd to protect the gearbox. It is limited where it needs to be, which is no-where near 4k. You'd not notice it when driving, you'd need to put it on a rolling road to tell the difference I think.

Dakta said:

Sometimes they have other variables too, like ambient pressure for altitude compensation as one example but not in our case.

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There is altitude compensation I think. That is why there is a MAP sensor inside the ECU I think.

Been a while since I've opened mine up.

Yep that's the one. Generally they are rated pretty low, 100kpa for the sdi's so sea level is pretty much bang on it's highest value, I suppose of you wanted to be picky you could also argue that you get a bit more precision with it, as the voltage range is the same as with a higher reading unit.

Sometimes the main map sensor is integral, as is the case with some of the vags and it's a bit of a solder job if you want to calibrate for running higher boost. (another reason to be thankful towards our older diesels )