Limp Mode

[Barras]

G'day guys, i've been looking here for a while and finally decided to post a question.

I don't know much myself about these cars but i'm trying to learn, anyway here is my question, i have a M35, when i floor it off the mark or when driving along and put the foot through the firewall the car goes onto limp mode, i then need to turn the car off remove the key start the car up again and continue on my way, i'm putting the car in for a service in the next couple of weeks and would like to be able to tell the mechanic what might need to be replaced to fix this.

Any advice would be appreaciated.

i was trying to wait until the next Vic cruise or even the SAU nationals when i could discuss these cars with others but need to get this resolved ASAP.

Thanks

Chris

[Sunkist]

may have a leak in the airflow system. mine would limp above 5k rpm and i found it to be my suction pipe was loose.

either that or the AFM.

[iamhe77]

I'd look at the AFM too.

How "east" are you Barras?

[scotty nm35]

Could be many things, even the throttle pedal wiring can cause that...

[iamhe77]

Just working the odds

[scotty nm35]

would like to be able to tell the mechanic what might need to be replaced to fix this.

If you need to tell him how to fix it, he isn't the man for the job. Have you worked out the codes yet?

What mods do you have if any?

[Barras]

Thanks guys i'll get him to check out the AFM, he was going to put it on the dyno to check what's going on but time didn't prevail.

Iamhe77, from Forest Hill

Have even looked at codes or anything like that, the missues just drives it to and from work and thats about it.

Car is standard as far as i know except for dual DVD players in the headrests (just got the cable to run the DVD's through the front screen yesterday), Brembo brakes, Volk TE73's 245x40x19 tyres, and some sort of body kit on it, leather interior.

(still working out how to reply to multiple messages)

[scotty nm35]

Is the engine light up?

[Barras]

Is the engine light up?

No, just the air bag light, i bought an adaptor through IM but it didn't fit.

[iamhe77]

When you say it goes into limp mode, does the yellow engine light appear?

I am pretty sure that this will always light up when in limp mode... unless the globe has gone of course

[Barras]

When you say it goes into limp mode, does the yellow engine light appear?

I am pretty sure that this will always light up when in limp mode... unless the globe has gone of course

Sorry yes it does.

[Jetwreck]

Sorry yes it does.

need to get the code.

http://www.m35stagea.info/forum/viewtopic.php?f=6&t=11

get that code and it should tell you whats wrong.

[Barras]

need to get the code.

http://www.m35stagea...ic.php?f=6&t=11

get that code and it should tell you whats wrong.

Thanks, i will give it a go next week when i get a chance.

[66yostagea]

While mine is a C34, I had the same probs. With it being intermittent it was hard to diagnose. Turned out to be the AFM.

[Barras]

OK the problem is the throttle position sensor, now i've just got to source one to test.

[Commsman]

OK the problem is the throttle position sensor, now i've just got to source one to test.

Would throttle re-learn procedure fix this? Even though it is used for idle speed, it may well fix it. The guys who have done this when cleaning out their throttle bodies may know...... In any case, it shouldn't take long to do the procedure. Info here: http://www.m35stagea.info/forum/viewtopic.php?f=6&t=206

Cheers, Leon.

[zei20l]

remember there is a throttle position sensor on the pedal and one on the actual throttle itself - actually i think there are 2 on the throttle.

if its only when you floor it, its possibly the one attached to the pedal

[Commsman]

If you want to easily check what Iain suggested, get a multimeter, earth one probe and check the voltages on the wires with the other. The voltage on pins 2 & 5 should be linear all the way to the floor. A sudden change (drop off?) would indicate a faulty potentiometer.

To get access you might need a pin to push thru the wires as the back of the connector is sealed.

[scotty nm35]

Its probably a dirty carbon track on the pot, there are two carbon tracks inside it. If you can pull it all apart and clean the tracks with contact cleaner it should be fine. Or just replace the throttle pedal sensor.

[zei20l]

i remember reading somwhere that V35s and Z33s suffer from the throttle input sensor malfunction