Low idle after changing chip

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jon_d_h
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Fri Feb 13, 2009 9:01 am

Hi

I recently swaped my ECU chip back from the wild chip to the standard chip in my ECU on my 325. Now, when idling, it is at 500 rpm and is nearly stalling.

Does anyone know what this could be?

Cheers

Jon
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no2lurch
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Fri Feb 13, 2009 9:03 am

the chip does lower the idle revs.

did you restart after resetting the ecu too? there is a correct procedure found on the wiki section.
jon_d_h
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Fri Feb 13, 2009 12:10 pm

no2lurch wrote:the chip does lower the idle revs.

did you restart after resetting the ecu too? there is a correct procedure found on the wiki section.
I have put my standard chip back in to see if I could cure a low performance issue but there is no noticable difference. Which chip do you meen lowers the idle revs?

If I didnt go through the correct procedure after fitting, is there any way I can do this now?

Cheers
j55ura
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Fri Feb 13, 2009 1:21 pm

I have the same problem and am not sure what to do, when I am moving and have to slow down or stop completely the engine sounds as though its going to stall. It never actually stalls but it is pretty annoying...... Mine has the mild chip, i don't remember if I had this problem before....

Any help would be very much appreciated!!
BMW 325i
asmith88
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Fri Feb 13, 2009 2:00 pm

i think sometimes the chips take a couple of drives to "learn"

i think you can reset the ecu again by turning ignition on for 10 secs, turn off, turn back on for ten seconds and then starting the engine. correct me if im wrong but thats if i remember correctly
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toby
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Fri Feb 13, 2009 2:41 pm

Did you drive the car after fitting the chip? If not take the car for a thrashing.
Chip fitting guide says it will be rough for a bit
http://www.e30zone.net/e30zonewiki/inde ... ting_Guide

If there is still a problem it's probably nothing to do with the chip.

Is the throttle switch set up right? It should click just as the throttle opens when the throttle linkage is moved by hand. I guess throttle switch as it could affect idle and performance (since wide open throttle switching is performed by the same).

Equally it could be something else - check for air leaks especially with split rubber pipes, clean out the idle control valve and check that it buzzes when you turn on the ignition. I'd also check distributor cap and rotor arm in relation to the low performance issue.

Let us know how you get on.
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jon_d_h
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Sat Feb 14, 2009 1:44 pm

toby wrote:Did you drive the car after fitting the chip? If not take the car for a thrashing.
Chip fitting guide says it will be rough for a bit
http://www.e30zone.net/e30zonewiki/inde ... ting_Guide

If there is still a problem it's probably nothing to do with the chip.

Is the throttle switch set up right? It should click just as the throttle opens when the throttle linkage is moved by hand. I guess throttle switch as it could affect idle and performance (since wide open throttle switching is performed by the same).

Equally it could be something else - check for air leaks especially with split rubber pipes, clean out the idle control valve and check that it buzzes when you turn on the ignition. I'd also check distributor cap and rotor arm in relation to the low performance issue.

Let us know how you get on.
Ok, I know there is nothing to do with air leaks as it was perfectly fine befor changing the chip and I didnt go under the bonnet. Il try reseting the ECU or disconnectling the battery for abit to see if the problem clears.

I noticed you said check the dizzy cap and rotor arm. How are these checked as I dont have a clue about these parts and where is the rotor arm.

Cheers
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toby
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Sat Feb 14, 2009 3:38 pm

You don't actually know it has nothing to do with air leaks unless you test it to be frank. You may have got an air leak at the same time by coincidence. Cars really are that annoying.

But you haven't said if you've driven the car, as it would need to be driven a bit after changing the chip to get it running right.

Also does the throttle switch click as I mentioned earlier?

It is worth checking before taking anything appart!

Putting that aside, the distributor cap is under a black cover held on by three bolts


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If you are standing and looking at the engine as above, the black cover (just here^) over those wires follow the HT wires from the spark plugs, remove that and check the rotor arm inside isn't starting to break up and the contacts inside the cap and on the rotor arm look clean.

These photos are from another site;
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