engine problems

[johnny_08]

like topic description says, i havent had time to see my mechanic today so thought id ask here. only happens while driving and not very often (once or twice on a 15 min drive) and it stalls at the lights sometimes, without even spluttering before.

[shakes]

what motor? :pokes:

[johnny_08]

sorry, bigport

[biggo]

Give us some leads here will you.

What have you tried?
Did you do any work on the car before it started playing up?
Checked TPS/loose wires?

[DRFT - 86]

sounds like the same issue I have with my car man..... its been going on for over a year now 16v 4age..
Its very random and annoying, wont do it for a month or so and then out of nowhere it will deciede to play games...
I will be just driving along or sitting at lights and it will just cut out, sometimes when driving I don't even notice, usually I can just flick the key on and off and it will be sweet although sometimes I have to hold the key while I drive which is fuckin annoying...... I have no idea what it is, got another engine and loom going in sooner than later hopefully so not greatly concerned with it... but yeh so far I have replaced the coil, leads, fuel pump, new earths, new dizzy rotor.. havent had it professionaly looked at but was told by a mechanic it was the ignition model that screws onto the back of the key barrel, told me to tighten it, but yeh that didnt do shit...

If you find out what it is I'd be interested to know... lol

[Golberg]

I have an idea to throw out there... are either of your ECU's JDM ones?

Apparently a lot of the JDM 4AGE ecu's were made with poor quality capacitors and they have a tendency to leak. Good idea to have a look anyway even if its an ADM one.

Once capacitors have started leaking they usually wont stop the device entirely from working, but just cause erratic errors. In my experience with desktop PCs with leaking caps the computer will work most of the time, but randomly restart or switch off, and symptoms will get worse until the thing dies completely. What I have also observed in the with PCs that have leaking caps is that there is usually a greater tendency for them to play up whilst its hotter, ie. the computer may be fine in winter, but become erratic during the summer.

Fear not, if that is the problem you just need somebody handy with a soldering iron and a handful of replacement capacitors and it can all be sorted. I've repaired a few computer motherboards myself like that.

Have a look on wiki at this article: http://en.wikipedia.org/wiki/Capacitor_plague

It'll explain to you what to look for, obviously you'll need to take the lid off the ECU.

If you find leaking caps I'd be happy to replace them for you for a fee, PM me if you're interested.

[DRFT - 86]

ahhh... hmm that would make sense... its JDM ecu also...
You may well be onto something..

[slide86]

<div class='quotetop'>QUOTE (Golberg @ Aug 24 2008, 07:09 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=579327)</div>
I have an idea to throw out there... are either of your ECU's JDM ones?

Apparently a lot of the JDM 4AGE ecu's were made with poor quality capacitors and they have a tendency to leak. Good idea to have a look anyway even if its an ADM one.

Once capacitors have started leaking they usually wont stop the device entirely from working, but just cause erratic errors. In my experience with desktop PCs with leaking caps the computer will work most of the time, but randomly restart or switch off, and symptoms will get worse until the thing dies completely. What I have also observed in the with PCs that have leaking caps is that there is usually a greater tendency for them to play up whilst its hotter, ie. the computer may be fine in winter, but become erratic during the summer.

Fear not, if that is the problem you just need somebody handy with a soldering iron and a handful of replacement capacitors and it can all be sorted. I've repaired a few computer motherboards myself like that.

Have a look on wiki at this article: http://en.wikipedia.org/wiki/Capacitor_plague

It'll explain to you what to look for, obviously you'll need to take the lid off the ECU.

If you find leaking caps I'd be happy to replace them for you for a fee, PM me if you're interested.[/b]

would this cause the car to run rough or poorly, and then after switching the car off and restarting it, the engine runs fine??

[Golberg]

<div class='quotetop'>QUOTE (slide86 @ Aug 24 2008, 08:02 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=579343)</div>
would this cause the car to run rough or poorly, and then after switching the car off and restarting it, the engine runs fine??[/b]
Could literally cause any number of problems, and its reasonably easy to check for.

If you want you can take the lid off take a good resolution photo of the board then post it up here and I should be able to tell you if it looks as if there is a capacitor problem.

[muncher]

fucken ecu's haha.. sounds like my problem.. but wont run atm... 1 more thing to check though...

[johnny_08]

sounds good. yea its a jdm ecu, but what would give evidence that a capacitor has leaked? (by looking at them) or would it be easier to replace them all?

Edit: i have only recently replaced the battery with a new one, old one died for some reason (only 1 yr old) and i have checked all wires and pipes but they all seem fine, i saw a thread on toymods saying it was the wiring going from the dizzy that was shorting out but the wires on my car were still fine.
Oh and my dizzy leaks oil as well.

[Golberg]

The only really way to tell if a capacitor has spat its guts is to visibly check it out, you can't really test them without pulling them off the board anyway.

In cases of ECUs doing this in the photos I've seen they usually leak out the bottom of the cap and often form a small amount of black substance around the bottom of them. Basically if there is any discolouration on the board underneath the cap you're probably in trouble. In the case that one capacitor is faulty its a wise precaution to go and replace all of them because you're only likely to have problems down the line otherwise.

I don't believe there is a huge many capacitors in there somewhere between 5-10 so it might be an idea to replace them anyway, I mean were talking 20+ years old electronics here stuff is likely to be a bit tired now especially since the JDM ECU's have a history. If you can take some good photos of the board inside the ECU box I should be able to tell from there for you.

Should also note, that if your dizzy is leaking oil from the inside it may very well be causing issues.

It is an interesting sign that between both you and DRFT - 86 you are both experiencing similar issues and at the same time both have JDM ECUs which aren't known for being super reliable.

And slide86, would I be right in saying this is for your 4AGZE motor? which would be a JDM ecu again?

I wouldn't say to everybody with engine problems to immediately jump to the ECU being the problem... but if you've tried other things and haven't succeeded then its relatively easy to check the ECU caps.

If I get a few people interested I'd consider picking up myself an old AE82 bigport ECU as a loan item so if people need their ecu's repaired and still need to be able to drive the car (assuming its not already undrivable) they can borrow it whilst I swap out the caps for new ones.

I mean that's assuming people don't already know how to do all this electronics stuff but I'm guessing there has to be some demand.