Tickover Trubbles!

[Bee Elzebub]

Well, got the MoT today, clean as a whistle! Fault codes x 2 = A) - Throttle Sensor, & B) - Airbag... now cleared off. (Throttle sensor was my fault - mentioned elsewhere - and airbag fault is...well.. a dud airbag, basically...)

Anyway, it still feels slightly slow/rough on tickover, and the MoT bay hasn't got the right 'dongle' to read/set the ECU setting, so I tried my friendly local Ford dealer (usually superb - do my vans each service), and their 'dongle' vanished long ago, even though their specialist confirmed that it's possible to re-calibrate the tickover setting in the ECU with the right software...so I tried a local diesel "specialist"; he shrugged, said it can't be done...and then said, "Bring it in, we'll see what we can do with it"... Yeh, right! Either you know what to do...or not...don't dare charge me for you cocking up my motor!

So, if it's possible to re-cal' the ECU, has anyone on here done so? If so, how? If not, would it be feasible, instead, to swap the ECU with another (identical engine spec) unit, to see if that brings up the tickover to the proper level of between 725-850rpm?:nenau

 

[solarman216]

as far as I'm aware cant be done without re chipping, just disconnect battery overnight should do it then the ecu goes into learning mode just drive 30 odd miles in different conditions and it re maps itself, Rick

 

[clivvy]

interesting, Rick, I have never actually tried this (i have minor tick over troubles, always have)

I cant suggest anything myself though, i have never been able to sort mine out.I didnt know there was a dealer dongle though, for re setting the ECU, so thats something to think about if unplugging the battery doesnt work...

 

[solarman216]

I am told that if you have the full Nissan consults software that you can actually change some of the settings, I have the freebe version that lets me read all the stuff on there, and temporarily I can play with the idle, trouble is the Nissan software is mega bucks, Rick

 

[lacroupade]

assuming this is a 'Terrano' Maverick and not the Mazda one, I'm sure you can only adjust tickover at the pedal pot.

 

[solarman216]

I should add, mine are Petrol, have not tried it on the diesel cars yet, Rick

 

[Bee Elzebub]

Yes, it's a Terrano-Maverick, and I tried the pedal-pot already, but all that did was mess up the ECU - it would start & tickover, but not rev (see other thread), so I reset the screw to its original position & it sorted itself out next start-up.

My Ford technician told me that if you go to a long-standing Nissan dealer, they're most likely to still hold both the dongle and the full Nissan ECU software, though I shudder to think how much they'd charge to reset & test the ECU, etc; might not be worth the hassle, so I think I'll do the battery-off trick soon & see what happens (ta, Solarman!).

Oddly enough, it seems to be settling down a bit now it's had a good run of the 60-mile round trip to Colchester & back home; maybe it'll behave itself now... Fingers crossed!

Thanks again for the helpful input, chaps!

 

[lacroupade]

Yes, it's a Terrano-Maverick, and I tried the pedal-pot already, but all that did was mess up the ECU - it would start & tickover, but not rev (see other thread), so I reset the screw to its original position & it sorted itself out next start-up.

My Ford technician told me that if you go to a long-standing Nissan dealer, they're most likely to still hold both the dongle and the full Nissan ECU software, though I shudder to think how much they'd charge to reset & test the ECU, etc; might not be worth the hassle, so I think I'll do the battery-off trick soon & see what happens (ta, Solarman!).

Oddly enough, it seems to be settling down a bit now it's had a good run of the 60-mile round trip to Colchester & back home; maybe it'll behave itself now... Fingers crossed!

Thanks again for the helpful input, chaps!

Maybe you over-adjusted it?

I'd be interested to see what Timbo thinks but I'm not convinced theres any tickover adjustment at ECU level unless its indirect, e.g. management of fuel flow or some other criteria, but thats not fixing the source of the problem is it.

 

[Timbo_1975]

Maybe you over-adjusted it?

I'd be interested to see what Timbo thinks but I'm not convinced theres any tickover adjustment at ECU level unless its indirect, e.g. management of fuel flow or some other criteria, but thats not fixing the source of the problem is it.

Well, as I understand it, when the idle switch on the pedal indicates err idle, then the ECU *should* refer to its idle map part of which contains a desired rpm, modifed by some % according to things like battery voltage, coolant temp etc. Therefore all T2's being equal they should all idle at the same rpm!

But they dont... I've not studied the stock ecu enough to establish why this might be though.. So dunno!

Is there anything in the workshop manual that says you should set a certain at rest voltage from the pedal sensor if you are replacing it ????

 

[Timbo_1975]

PS- i've just thought... If the idle switch is BROKEN and never indicates "idle" to the ecu, then the ecu will give an rpm directly according to the volts from the PPS, which could be really low ???

Think someone needs to get hold of a PPS and disect it!

 

[lacroupade]

PS- i've just thought... If the idle switch is BROKEN and never indicates "idle" to the ecu, then the ecu will give an rpm directly according to the volts from the PPS, which could be really low ???

Think someone needs to get hold of a PPS and disect it!

Well I'm with you (albeit on a lower level LOL), in that I've heard of such a problem being resolved by fitment of a new throttle pedal switch, which would support what you're saying.....

 

[Bee Elzebub]

That'll be the switch below the PPS, that operates as the pedal starts to lift off it, I presume? If so, I'll have a play with my switch tomorrow (Sunday) & see what happens...

By-the-way - I squirted a bit of spray-grease on the PPS drum the other day as it felt like it was sticking...and now it revs, dies, revs, runs @ 2000rpm, dies... BLOODY SENSITIVE POXY THINGS!!!! Another strip-down job coming up for the contortionist (ME!)... :-(

All together, now: If it ain't broke, don't fix it...

 

[lacroupade]

That'll be the switch below the PPS, that operates as the pedal starts to lift off it, I presume? If so, I'll have a play with my switch tomorrow (Sunday) & see what happens...

By-the-way - I squirted a bit of spray-grease on the PPS drum the other day as it felt like it was sticking...and now it revs, dies, revs, runs @ 2000rpm, dies... BLOODY SENSITIVE POXY THINGS!!!! Another strip-down job coming up for the contortionist (ME!)... :-(

All together, now: If it ain't broke, don't fix it...

You said it LOL.

I'd just swap the little bleeder but then I'm a lazy SOB! :augie

 

[Bee Elzebub]

Sussed it - I hope! Stripped & cleaned the damper (on the left-hand end) as it was a little slippy...but all I did was refitted it, plugged the wiring in firmly - job's a good 'un!

Ran fine in a ten-mile blast afterwards, so that (I hope) is that...

MEMO TO SELF: "Leave the bloody thing alone...!"