Major running problems on the XU9J4!
- kriskarrera
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- Joined: Mon Sep 18, 2006 9:54 pm
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Major running problems on the XU9J4!
A few nights ago I made a short journey into town. The engine started and drove fine for 5 minutes and then midway through warming up it started missing badly for a few minutes and then it completely died! So, I restarted her. And it was ok....
The next day I was a bit I miffed. But I found the TPS connector to be loose and thought it might be that.
Alas I did the same journey tonight and the problem happened in exactly the same time and way as a few nights ago!
A bit of background...
Engine has always had a starting problem.
Starts fine when stone cold. Starts fine if it was switched off and restarted within about five minutes. But after that approx. 5 minutes and say 12 hours it will turn over for 5-10 seconds before reluctantly starting.
Also...
If I'm drifting along in traffic at say 2000rpm in 2nd gear with foot off gas pedal and then I go to accelerate the car will jerk a few times before smoothing out. And when taking foot off accelerator it jerks again as if the fuel cut off wasn't immediate...
I'm thinking all these are related!!
Anyone else experienced this or have any ideas what could be causing this?
Thanks
Kris
The next day I was a bit I miffed. But I found the TPS connector to be loose and thought it might be that.
Alas I did the same journey tonight and the problem happened in exactly the same time and way as a few nights ago!
A bit of background...
Engine has always had a starting problem.
Starts fine when stone cold. Starts fine if it was switched off and restarted within about five minutes. But after that approx. 5 minutes and say 12 hours it will turn over for 5-10 seconds before reluctantly starting.
Also...
If I'm drifting along in traffic at say 2000rpm in 2nd gear with foot off gas pedal and then I go to accelerate the car will jerk a few times before smoothing out. And when taking foot off accelerator it jerks again as if the fuel cut off wasn't immediate...
I'm thinking all these are related!!
Anyone else experienced this or have any ideas what could be causing this?
Thanks
Kris
XU9J4 4ever
You could check everything! most people seem to start by tearing the airflow meter into a thousand peices - dont!!.
If you don't have the test equipment just start with ignition.
Leads - are they kinked or dirty, are they all approx 2K Ohm to 6 K?
Cap, clean, unscratched internally, does the centre elctrode still slide/ spring to the rotor arm?
Coil, check resistances on secondary and primary compare to Haynes but in general looking for low single figure resistance on primary and 20k secondry, certainly not Mega ohms.
Is the coil intermotor? if so get a spare for when it does fail!!- because it looks like the one from a 1.4 Ax they see fit to buid them like one
Ignition amp, if coil had failed this will be cooked anyway 90% of the time.
What make is it? Bosch IS best. intermotor and spurious aren't. - look for a brand.
They can't be easily tested except by watching how they behave under load with a crypton type machine or scope.
MINE HAS SO FAR EATEN 1 A YEAR!! they are allways my first port of call!! but check coil first so it doesn't kill the new one.....
If you cahnge one make sure to use the heat conducting grease on the back
What are the connections like? clean and dry? if not clean and seal with a little silicone grease - multiplug on coil and on AMP.
other possibilitys get more complicated The TDC sensor wiring can get interference and can get damaged by clutch changes and running against the HP belt.... but otherwise generally bulletproof if the old metal cased Bosch one.
Happy hunting but I would place a round of drinks on coil and amp without even driving it!
But do geta meter and do the WHOLE sequence, just cos you remember doing one item some time doesn't mean its still oK!!
Having dione the whole ignition checks, you may now move onto other likelys causes normally stuff like:
If it only happens at idle theres the nice little idle switch which may need a clean, or the throttle cable sticking and holding it open?
Temp sensors lying about how hot it is, might explain its longer term hot start probs but could be dirt on contacts skewing the readings.
- and of course everyones favourite the airflow meter
best to check by substitution with a good car next time you meet someone with one otherwise you will just tinker with youre own wasting time and money...
If its any consolation very few start well when hot,
And as a word of caution if parts pass the tests above don't go buying them just for a laugh, a good multimeter costs £20 whereas most of the bits cost much more!!!
If you don't have the test equipment just start with ignition.
Leads - are they kinked or dirty, are they all approx 2K Ohm to 6 K?
Cap, clean, unscratched internally, does the centre elctrode still slide/ spring to the rotor arm?
Coil, check resistances on secondary and primary compare to Haynes but in general looking for low single figure resistance on primary and 20k secondry, certainly not Mega ohms.
Is the coil intermotor? if so get a spare for when it does fail!!- because it looks like the one from a 1.4 Ax they see fit to buid them like one
![Mad :x](./images/smilies/icon_mad.gif)
Ignition amp, if coil had failed this will be cooked anyway 90% of the time.
What make is it? Bosch IS best. intermotor and spurious aren't. - look for a brand.
They can't be easily tested except by watching how they behave under load with a crypton type machine or scope.
MINE HAS SO FAR EATEN 1 A YEAR!! they are allways my first port of call!! but check coil first so it doesn't kill the new one.....
If you cahnge one make sure to use the heat conducting grease on the back
What are the connections like? clean and dry? if not clean and seal with a little silicone grease - multiplug on coil and on AMP.
other possibilitys get more complicated The TDC sensor wiring can get interference and can get damaged by clutch changes and running against the HP belt.... but otherwise generally bulletproof if the old metal cased Bosch one.
Happy hunting but I would place a round of drinks on coil and amp without even driving it!
But do geta meter and do the WHOLE sequence, just cos you remember doing one item some time doesn't mean its still oK!!
Having dione the whole ignition checks, you may now move onto other likelys causes normally stuff like:
If it only happens at idle theres the nice little idle switch which may need a clean, or the throttle cable sticking and holding it open?
Temp sensors lying about how hot it is, might explain its longer term hot start probs but could be dirt on contacts skewing the readings.
- and of course everyones favourite the airflow meter
![Laughing :lol:](./images/smilies/icon_lol.gif)
If its any consolation very few start well when hot,
And as a word of caution if parts pass the tests above don't go buying them just for a laugh, a good multimeter costs £20 whereas most of the bits cost much more!!!
- kriskarrera
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- Joined: Mon Sep 18, 2006 9:54 pm
- Location: Wiltshire
Wow! That's a good reply!
One of the problems with testing various things is that of course the testing has to be performed when the engine is playing up. Though letting the engine get hot and then leaving it for an hour is usually a good time for the slow starting to appear.
One thing I might do is pull off the HT leads and stick spare spark plugs in them and try to start it when it's getting dark to see what the spark is like.
I tried heating up the ignition amp with a hair drier just now but the car still started fairly quickly (as it does first thing when left overnight) so that eliminates that. In theory.
What's your car eaten a year? Ignition amp? Or coil?
Can you describe in more detail how to test the coil with my multimeter please?
I've got 2 spare coils, both old though. And a spare CTS, TPS, ISCV, and AFM.
Thanks
One of the problems with testing various things is that of course the testing has to be performed when the engine is playing up. Though letting the engine get hot and then leaving it for an hour is usually a good time for the slow starting to appear.
One thing I might do is pull off the HT leads and stick spare spark plugs in them and try to start it when it's getting dark to see what the spark is like.
I tried heating up the ignition amp with a hair drier just now but the car still started fairly quickly (as it does first thing when left overnight) so that eliminates that. In theory.
What's your car eaten a year? Ignition amp? Or coil?
Can you describe in more detail how to test the coil with my multimeter please?
I've got 2 spare coils, both old though. And a spare CTS, TPS, ISCV, and AFM.
Thanks
XU9J4 4ever
- kriskarrera
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Bit of news...
I just pulled all the HT leads off and stuck some spare spark plugs into them and tried to start the engine. Did I get sparks? Yes - BUT each plug sparked in firing order as if the engine was turning over about 20rpm! What does that indicate? (when the starters turning engine over it's doing over 100rpm isn't it?)
I've done some research.
The starter motor turns the engine at 165rpm. So assuming one spark per revolution of crank I shoulda been seeing a spark every 0.36 of a second. Well I was seeing about a quarter of that many sparks!
I just pulled all the HT leads off and stuck some spare spark plugs into them and tried to start the engine. Did I get sparks? Yes - BUT each plug sparked in firing order as if the engine was turning over about 20rpm! What does that indicate? (when the starters turning engine over it's doing over 100rpm isn't it?)
I've done some research.
The starter motor turns the engine at 165rpm. So assuming one spark per revolution of crank I shoulda been seeing a spark every 0.36 of a second. Well I was seeing about a quarter of that many sparks!
XU9J4 4ever
- Timmo
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one hting i owuld be tempted to say is try and 'jump' your starter from a direct feed and see if the engine fires over quickly when warm, if so could indicate that the wiring tot he starter is on its way out!?!? the common easy fix is the relay in the system but if its as gone as mine then you will need to put in a starter button or equivalent direct to the motor. makes an awful lot of difference! as does fitting a zx td starrter motor as it has a little more poke (1.1 hp compared to .9hp) to tun the engine over!
another indication of poo sparking could be cap and arm! when i rerplaced the head on mine i put a new cap and am on and whilst cold it was fine but as soon as it was up to temp it woldnt fire up (would cut out when running) tried everything (removed and re did the cambelt etc before changiong the cap!)
hopefully its something very simple!
another indication of poo sparking could be cap and arm! when i rerplaced the head on mine i put a new cap and am on and whilst cold it was fine but as soon as it was up to temp it woldnt fire up (would cut out when running) tried everything (removed and re did the cambelt etc before changiong the cap!)
hopefully its something very simple!
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Its Because its French!
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![Cool 8)](./images/smilies/icon_cool.gif)
After all i am the Cornish one!
Its Because its French!
Bx16v club - Sharing the love for the unloved!
Some of the test you do both cold and hot! mines eaten 5 ignition amps, and 3 coils in my custody!! all the amps were intermotor or spurious and the coils were all intermotor!! hopefully now its on a Bosch amp and Beru coil it'll last,,,, tell you in a year
coil testing you test priamry using the terminals on top, secondary you usethe HT terminal and the body of the coil.
if you really have too many sparks is it scattering all over the inside of the dizzy cap? easy way to check is to put the rpm guage from a gunsons or other diagnostics meter on the coil and se what rpm it suggests- if its a sane starting speed so be it , check cap onwards in sytem but if its getting lots of random pulses then you have to work back to AMP, ECU, then TDC. but too many pulses is very very unlikely!!!
![Laughing :lol:](./images/smilies/icon_lol.gif)
coil testing you test priamry using the terminals on top, secondary you usethe HT terminal and the body of the coil.
if you really have too many sparks is it scattering all over the inside of the dizzy cap? easy way to check is to put the rpm guage from a gunsons or other diagnostics meter on the coil and se what rpm it suggests- if its a sane starting speed so be it , check cap onwards in sytem but if its getting lots of random pulses then you have to work back to AMP, ECU, then TDC. but too many pulses is very very unlikely!!!
- kriskarrera
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- Timmo
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see, now i have never had any issues with intermotor! Mycar is on an intermoto coil and amp! the coil was changed 4 years ago when it went wrong for the intermotor and the amp was changed when i had engine issues 6 years ago! and i have never had any issues with them!! (touch wood!)
my old 309 gti used to run fine on them too!
my old 309 gti used to run fine on them too!
Timmo ![Cool 8)](./images/smilies/icon_cool.gif)
After all i am the Cornish one!
Its Because its French!
Bx16v club - Sharing the love for the unloved!
![Cool 8)](./images/smilies/icon_cool.gif)
After all i am the Cornish one!
Its Because its French!
Bx16v club - Sharing the love for the unloved!
- docchevron1472
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Er, unless you have the worlds only 2 stroke XU9 then it should spark every other rotation of the crank, since it's a 4 stroke engine...kriskarrera wrote: So assuming one spark per revolution of crank I shoulda been seeing a spark every 0.36 of a second. Well I was seeing about a quarter of that many sparks!
1990 BX 16v Phase 2
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1989 BX TD hybrid
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That's when I reach for my Revolver
- kriskarrera
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But I didn't mean "per cylinder", I meant one spark per any 4 of the cylinders.
A few years ago when the b@stard wouldn't start I noticed the "K" light wouldn't be illuminated. I did a few checks back then and discovered a loose connection on the main relay's socket. Did my best to tighten it back then and it improved. But perhaps there's still some sort of a loose contact there that's only truely loose when the engine bay gets warm.
A few years ago when the b@stard wouldn't start I noticed the "K" light wouldn't be illuminated. I did a few checks back then and discovered a loose connection on the main relay's socket. Did my best to tighten it back then and it improved. But perhaps there's still some sort of a loose contact there that's only truely loose when the engine bay gets warm.
XU9J4 4ever
- docchevron1472
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The number of these I've done work on and found the spark plug leads not actually firmly connected to the topp of the plug, I've lost count of.
They will jam both at the point where the rubber on the lead goes down the porcelain as well as that big square knob at the top where it fits in the valley between the cams.
The effect is that it intensifies the spark and often this causes the spark to often arc against the head after the engine's run for a while.
Crap on the outside of the coil is another one that can give some weird symptoms too as the LT plug contains connections both + and - and these can also short on the build up of conductable coating that builds on them as does the HT from the centre terminal.
I usually give the coil several washes to rid it of all this garbage and when fitting plug leads always use a silicone spray so the plug leads slip nicely down the valley and give a distinct "click" when pushed onto the plugs.
I've had so much problem with these over the years, I can't believe some of you guys haven't given the wetter climate and the salt on the roads.
Alan S
They will jam both at the point where the rubber on the lead goes down the porcelain as well as that big square knob at the top where it fits in the valley between the cams.
The effect is that it intensifies the spark and often this causes the spark to often arc against the head after the engine's run for a while.
Crap on the outside of the coil is another one that can give some weird symptoms too as the LT plug contains connections both + and - and these can also short on the build up of conductable coating that builds on them as does the HT from the centre terminal.
I usually give the coil several washes to rid it of all this garbage and when fitting plug leads always use a silicone spray so the plug leads slip nicely down the valley and give a distinct "click" when pushed onto the plugs.
I've had so much problem with these over the years, I can't believe some of you guys haven't given the wetter climate and the salt on the roads.
Alan S
- kriskarrera
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- kriskarrera
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- Posts: 98
- Joined: Mon Sep 18, 2006 9:54 pm
- Location: Wiltshire
On the 405 the ecu is mounted onthe inner nearside wing in a small area between the interior of the car and the bulkhead. This area is not sealed in any way therefore it will fill with water when it's raining or if like me you use alot of water when washing the car. There is a drainhole that leads immediately to the wheel arch. But if it's really pissing it down I reckon the water could be very slow to drain out when there's also water spraying off the tyre at high velocity and of course most people never think to clean this area and it fills with mud and leaves.
My couple of recent engine cutting outtings coincided with it raining. Might be linked.
Click on the pictures to see them in full size....
[img=http://img154.imagevenue.com/loc1189/th ... 1189lo.JPG][img=http://img14.imagevenue.com/loc619/th_3 ... _619lo.JPG][img=http://img45.imagevenue.com/loc712/th_3 ... _712lo.JPG][img=http://img186.imagevenue.com/loc573/th_ ... _573lo.JPG]
My couple of recent engine cutting outtings coincided with it raining. Might be linked.
Click on the pictures to see them in full size....
[img=http://img154.imagevenue.com/loc1189/th ... 1189lo.JPG][img=http://img14.imagevenue.com/loc619/th_3 ... _619lo.JPG][img=http://img45.imagevenue.com/loc712/th_3 ... _712lo.JPG][img=http://img186.imagevenue.com/loc573/th_ ... _573lo.JPG]
XU9J4 4ever
I would be careful about how much crap and stuff gets into that area, but in all honesty, I'd reckon that for every 100 ECUs that get replaced you'd be lucky if 2 really needed it.
Rather than being the work of the devil we all tend to look at them as, the ECU is possibly one of the least troublesome parts of the whole system and let's face it, if it were as vulnerable as they often get reputed to be, wouldn't you think that the manufacturers would be looking for ways to seal them off from all kinds of moisture contamination as they do on auto washing machines.
On them, water is rarely a problem, usually insects and mice chewing through a vital section often takes them out.
I think you might be looking for a complex solution to a simple problem. (which isn't hard to do)
Stick with coil, leads, igniter and general wiring in that vicinity and I reckon you'll pick it up.
Alan S
Rather than being the work of the devil we all tend to look at them as, the ECU is possibly one of the least troublesome parts of the whole system and let's face it, if it were as vulnerable as they often get reputed to be, wouldn't you think that the manufacturers would be looking for ways to seal them off from all kinds of moisture contamination as they do on auto washing machines.
On them, water is rarely a problem, usually insects and mice chewing through a vital section often takes them out.
I think you might be looking for a complex solution to a simple problem. (which isn't hard to do)
Stick with coil, leads, igniter and general wiring in that vicinity and I reckon you'll pick it up.
Alan S