Fordjared

Yes you can wait until the cap bursts and bulges out, an ESR meter will pick a leaky cap up way before they get to this point. They can cause problems before physical symptoms come along. Just so you know...

tiny56

The caps out of my ECU unit were 105 deg C items so they got that bit right

Scooter

good post scooter....

should be made a sticky?

hmmm...interesting...might replace mine...piss easy to do...

we have an LCR bridge at work (work being an avionics workshop) so that will let me see what the caps are like once I pull them out...

Wont do any harm either way, as my idle ain't as smooth as I'd like!

Nice find!

*fiftyone pays hommage to Scooterxf*

nice one, how'd you figure it all out?

Although I accept all praise , I will wait to see if it fixes anyone else’s problems before I would except that it is a genuine fix.

I did a search through the forums looking for info on this idling problem and discovered a post talking about a blown earth path (in the ECU module) on the IC that controls the PWM current to the air bypass valve. His theory was that if the valve jams it will increase the current to the driver IC and it will blow the track. This made sense in my case because my vehicle is on gas and the entire inlet tract had been split and cracked from backfires so I suspect the valve had had a hard time. So I pulled the ECU out and immediately noted the caps and suspected them.

In hindsight I don’t think that the other guys post was right - if the valve jammed I don’t think there would be enough current to blow the track off the PCB. My new valve measured 10 Ohms and if you use Ohms law – I = V/R -> I = 12V/10Ohms -> I=1.2Amps. This isn’t enough current to blow tracks off the PCB, not in the location he specified anyway. The IC and PCB would be able to handle this easy. Even if he shorted the leads to the ICV I don’t think the PWM circuit in the ECU could supply this current – so I don’t now how he blew it up like that…

Scooter

If the ISC or associated wiring was shorted, then the PWM driver would be increasing pulsewidth to near on 100% to try get the engine RPM up. Being shorted means the mosfet is effectively trying to bring the 12v supply rail down to 0v, more than enough current to burn the track.

If the ISC jams, it wont make any difference as the internal impedance will remain unchanged.

would other cars around the same time have the same sorts of problems? like vs commos and magnas or whatever? dont know much about them

and how do you tell there actally blown? they crack open or something?

I Hi i got an EF, and i have idle problem when the car is cold and especially when a/c is on!! i have got another ICS and cleaned it.!!
I only had this problem when i change from auto to manual ecu.. I im 90% sure its the ECU at FAULT.

Scooterxf i have got the capacitors.. just have 2 put it in!! mmm bit scared..
Is there anyone else who has tryed this??

i had an idle problem, i changed the ics never made a differnce especialy when the ac cut in and out. but when it was cold it idled fine?!...but i reclently discovered that the timming chain guide on the left the top had broken and the tensioner had gone to full length and wasnt keeping the chain tight, (well i assume anyway) once i changed the guide and tensioner it idled smoother than what it did when i got the car over a year ago. may have nothing to do with anyone elses problem but worth a look down the rocker cover

Just did it, i changed the capacitors to new ones!! Does not make a difference!! still the same sh** idle.. Any suggestions? aftermarket comp?

why is this not a sticky? it's probably the best thread for ages

Thanks champ! I've got an idle / ignition issue thats been dogging me for ages. Might have to look into this one at some point. So far my ideas have come to leads and Coil Packs but I havent changed either of those yet so I'm not sure wot the go is.

I'll def keep this in mind! I'm not too electronically adept, so I might take it to a sparky and ask em to test around that area.

ahh good old electrolytic capacitors... I have had a few die on me in the past. Just thought I would caution ppl who are thinking of replacing them... If your not good at soldering get someone who is. The PCB in the ECU is multi layered and it is a lot more tricky to PROPERLY de-solder the old caps and solder in the new ones.

good work Scooterxf

cause only 1 guy so far has tried it and it didnt work probably!??!?

to fix the idle on my ef i converted to straight lpg.
i also cleaned the crank angle sensor. it was covered it gunk.
my car also has a dead/faulty cam sensor. the ecu continually throws a code for it. now that im on straight gas it still has the faulty cam sensor but still idles perfectly.
also fitted a spacer under the isc, (KIT IDLE SPACER; AUC 9B571A $17.30) this smoothed out the idle dramatically.
before i fitted this plastic spacer the idle would be rough whenever the engine changed to lean. now it runs the same whether the mixture is rich or lean.
(my lpg mixture controller has leds for rich & lean)
my ef wouldnt idle smoothly running in closed loop until i fitted the spacer. I had to set the computer to be in open loop and run a rich mixture for a smooth idle before.
i would like to hear from anyone else that has fitted the isc spacer and has noticed an improvement on a petrol ef/el. usually it is only fitted to tickford gas ef/el's.

 

 

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very true this is fitted to the tickford gas intakes. I was wondering if it was available still?
apparently it was put there because where the factory one goes, it makes cylinder 3 and 4 burn differently to the rest of them when the engine has a bit of blow by.
something along those lines!
cheers
sam