Rev trouble

JamietypeR · February 20, 2010, 10:36:48 AM

Hi guys taken my Mazda out for a drive today n withen 20mins of driving the revs jump from 1000 to 1500 up down up down about ten times then it levels out again, does anyone kno wat cud be the problem, it\'s running n apexi ecu

Aubec · February 20, 2010, 11:06:09 AM

What water temps is it reading?

Mine revs the engine when its in neutral if the water is above 93 degrees, and then levels out as soon as the water drops below that temp again.

I figured it was maybe a measure to helpn cooling as the water pump will circulate water faster round the block at higher revs, but TBH I have no idea if thats really why or not.

philiwily · February 20, 2010, 12:34:14 PM

Quote from: JamietypeR;673674Hi guys taken my Mazda out for a drive today n withen 20mins of driving the revs jump from 1000 to 1500 up down up down about ten times then it levels out again, does anyone kno wat cud be the problem, it\'s running n apexi ecu

This is a common problem with the PFC and there are lots of things you can adjust but if it was ok before you might be needing new plugs.
Upping the idle and idle cut can help.

Phil

turbotoaster · February 20, 2010, 12:47:12 PM

mine does the same thing, its like its learning how to idle when you first plug it in, i just let it get on with it for a couple of seconds, silly thing hasnt learnt to idle the car properly

whats idle cut phil?

JamietypeR · February 20, 2010, 12:56:10 PM

Yea it is like it\'s learning again, what\'s the best plugs to put in the car?

turbotoaster · February 20, 2010, 01:01:59 PM

if its a good compression engine then 9s all around, 7 and 9s if it isnt....i assume just standard car with a power fc?

JamietypeR · February 20, 2010, 02:38:17 PM

Yea it should have good compression as it was rebuilt about a 1000miles ago, the only mods on the engine are apexi ecu blitz dumpvalve n a decate full exhaust, from when I first put the apexi in it self learnt then it wud go up n down on the rev n be fine, but just today it\'s going up down a good 10 times before it levels out, I\'ll get sum new spark plugs n see if that helps, where abouts is the idle n idle cut located?

neil_jdmr · February 20, 2010, 06:43:28 PM

ngk-bur9eq are the plugs of choice Jamie.

Aubec · February 20, 2010, 07:48:37 PM

Don\'t think is the plugs dude - made no difference to mine when my plugs were all changed as part of a service.

JamietypeR · February 20, 2010, 07:56:49 PM

Cheers neil, it\'s weired cos after driving for a while it stopped doing it again, n I went onto the motorway n it had trouble when accelerating to 100mph felt like it was hesitating n didn\'t wanna go faster? Think I need to have it looked at tbh by a specialist

neil_jdmr · February 21, 2010, 08:43:16 AM

just change the plugs dude its a peice of ...., although like Aubec said its probs not the plugs but easy to find out.

JamietypeR · February 21, 2010, 09:02:47 AM

Yea I\'ll go pick up sum today, but still think I might get sum1 to look over it as I haven\'t got a clue what to look for on the PFC controller n there\'s black dots all over the place in channel 1,

philiwily · February 21, 2010, 04:26:37 PM

Quote from: turbotoaster;673692mine does the same thing, its like its learning how to idle when you first plug it in, i just let it get on with it for a couple of seconds, silly thing hasnt learnt to idle the car properly

whats idle cut phil?

Idle cut are the 3 rows of numbers below the 3 rows of idle settings (in setting- rev/idle).
It controls the point the fuel comes back on after the fuel cut caused by deceleration, also affects the revs the engine sits at just before it drops down to its final idle, a bit like a dash pot.
Hope that makes sense.:2Confused
Phil