Technical 1.9 16v Erratic Idle at cold start

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Technical 1.9 16v Erratic Idle at cold start

Still thinking on the correction at zero on the one injector.

When balancing the air flow through four carburettors then one will/should have its correction path closed off. I'm think that statically for the injectors then the same is true to an extent.

Now this can get very complex but I'm thinking that most ECUs are not that sophisticated for the following reasons

1) there is no per cylinder lamba sensor on most cars thus individual inject/cylinder fuelling level is not monitored based on combustion readings

2) this only leaves an ignition timing / combustion event and as say No:1 combusts the ECU monitors the net acceleration, and does the same for every cylinder fire and then leans or richens the per cylinder/injector ratios to get a smooth rhythmic pulsation of the engine.

3) doing 2) is still possible all based around a chosen "prime" injector.
 
That theory is right, but until now, my engine is the only one with the inj 1 on 0. So that theory doesn't apply at our ECU for 1.9 and 2.4. There should be a correction. That's why this is a problem, because others have correction on injector 1. Here is a video with a cold start filmed from outside the car:
 
Now a different tack.

I've observed both my tacho making small changes in needle deflection under what I would consider to be constant situations.

I've seen the speedo rock stead but the tacho dip by 100 or so rpm and sensed no motion change.

It is more rare to see a constant tacho but an indicated speed change.

The speedo and tacho and fuel and temp, in fact all instrument cluster is driven via the CANBus with commands to tell the speedo to show 50mph and the tacho to show 1800rpm etc. etc.

By design some dash components will be high priority items. The speedo and mileage/trip and fuel consumption would be my chosen high priority. The tacho I suspect is a lower priority gauge.

So another train of thought is that on a cold start the ECU and body computer are working flat out to start the engine, keep it running and adjust all sorts of parameters at the same time. This could lead to a latency/lag in tacho CANBus information so instead of the tacho commands coming every 200ms the come every 500ms then every 300 then every 200 and so on. Depending on the tacho needle analogue damping you may or may not see late command updates.

Old older cars the engine rpm sensor sent a pulse directly to the tacho. No computer involved. Today the pulse is sent to the ECU and that ECU sends that pulse to the body computer (in the case of the Croma as the ECU is not CANBus based) and the Body Computer takes that plus and sends the information via the CANBus to the instrument cluster.

I suspect that if we all very carefully monitor our tachos whilst driving at constant speed whilst making other demands on the cars computer systems we will see small varioations in tacho needle position.

I certainly do.

Prove me wrong (famous last words).
 
I can't prove you wrong, you are right, seen it myself sonetimes, but the tacho is not the issue here. Your theory is good, but has nothing to do with the problem I'm facing and I hope it doesn't get viral :) Anyway, earlier I did a small test in which I manually preheated the glow plugs 15 seconds and problem was 70% gone. So I'm thinking that even if the glow plugs are not broken so ECU could thow an error, they may be just slow. I still didn't found out what impedance has a new glow plug.
 
Glow plugs still run for a period AFTER the glow plug enunciator has been extinguished.

In cold weather when I start my Croma I leave the ignition in position one for up to 10 or more seconds before going to the start position. This has solved and reduced many of my otherwise extremely rough or abortive engine start problems.

This could be a software problem. For me the glow plug light always illuminates for the same period of time regardless of the outside temperature. So why would the ECU energise a glow plug for say 5 seconds in the summer and do the same at -5 deg.C.

But I'm also 100% pretty sure the glow plugs are powered for a while longer after the glow plug light goes out.

Unlike a petrol engine a cold diesel engine is a law unto itself!
 
Cold start this morning.

At idle the rpm needle fluctuated about 100 to 150 with no noticeable engine speed change. The immediately lifted revs to 2000rpm and the fluctuations still present. Back to idle, same again. Up to 2000, same again. Drove off.

Later at traffic lights when car was warmer (but by no means fully warm) the rev counter needle was pretty rock steady at idle and 2k rpm.

I'm fairly happy with my theory :)
 
AND NEVER EVER give up on these old skills which/where the current generation just don't understand the basics. Give then an old distributor, dodgy points, dodgy capacitor, brittle/internally broken carbon spar plug leads, as then to statically time and set dwell, (I could go on) and you will struggle to find any/many current dealer technicians that can do this.

And I'm fed up with the "the manufacturer's computer diagnostics say x, y, z so we need to replace a, b, and c .... and for good measure d and e as well."
Just got back from a long w/e in Edinburgh:D.
A true story my son told was - when I bought the Croma he took over my old Marea Weekend 1.9 diesel as the price px i was offered was an insult really. He took it inti Kwik Fit i Leeds to have a MOT ( against my better judgement). He was charged an hour extra labour for the "setting up of the timing". He rang me before paying for this and there was a three way conversation while he was in Kwik Fit , I said ask him what they did to adjust the timing The "technician " said he used a strobe light as usual on No1 spark plug!!! after I stopped laughing I said for him to get the "technician" to show him the spark plug he used as it was a diesel.
The "manager" then got involved and drew up a new bill minus the "extras" and said the "technician " had got his cars mixed up!!!:devil:
 
You can still listen to them if you like, leave the tablet, put your boots on, get outside and get your hands dirty :)
Ah yes those were the days :eek: I only use the little grey cells now if I can get away with it. The last job I have done for myself was fitting a new EGR and cleaning the boost sensor. The back of my legs were so achey afterwards it took me two days before I could walk the dog! :p
 
Glow plugs still run for a period AFTER the glow plug enunciator has been extinguished.

In cold weather when I start my Croma I leave the ignition in position one for up to 10 or more seconds before going to the start position. This has solved and reduced many of my otherwise extremely rough or abortive engine start problems.

This could be a software problem. For me the glow plug light always illuminates for the same period of time regardless of the outside temperature. So why would the ECU energise a glow plug for say 5 seconds in the summer and do the same at -5 deg.C.

But I'm also 100% pretty sure the glow plugs are powered for a while longer after the glow plug light goes out.

Unlike a petrol engine a cold diesel engine is a law unto itself!

There is a very big difference between 5 and -5 at least on my Croma, the glow plug light stays on for about 7 seconds at -5 and only 3 at 5 degrees. After the light goes off, the glow plugs are no longer powered, they still hot, but no power is delivered to them, that's the whole idea of the glow plug indicator light. I even tried your way of starting the car with 10 seconds, even 15 seconds rule, but I had no change. I'm fairly sure there is something wrong with a glow plug or two, but I am still searching for the impedance of a new glow plug to decide which of my two are "tired". And yes, I give you credit for the last sentence, that is true :)
 
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Just got back from a long w/e in Edinburgh:D.
A true story my son told was - when I bought the Croma he took over my old Marea Weekend 1.9 diesel as the price px i was offered was an insult really. He took it inti Kwik Fit i Leeds to have a MOT ( against my better judgement). He was charged an hour extra labour for the "setting up of the timing". He rang me before paying for this and there was a three way conversation while he was in Kwik Fit , I said ask him what they did to adjust the timing The "technician " said he used a strobe light as usual on No1 spark plug!!! after I stopped laughing I said for him to get the "technician" to show him the spark plug he used as it was a diesel.
The "manager" then got involved and drew up a new bill minus the "extras" and said the "technician " had got his cars mixed up!!!:devil:

Well done, you showed all of them a lesson. I'm thinking, how many we're tricked before :)

Ah yes those were the days :eek: I only use the little grey cells now if I can get away with it. The last job I have done for myself was fitting a new EGR and cleaning the boost sensor. The back of my legs were so achey afterwards it took me two days before I could walk the dog! :p

Ouch :) I know what you're talking about, I'm only 33, but I have an hereditary problem with my back and I can't stay lift weights or stay crouched, I get a ache immediately and the position to work on Croma is painful. Cheers !
 
I'm fairly sure there is something wrong with a glow plug or two, but I am still searching for the impedance of a new glow plug to decide which of my two are "tired".

Resistance below 5 ohms is accepted as good.

See here: http://www.ngk-dpower.com/index.php?id=31&L=2

Also good info here: http://www.ngk.de/fileadmin/templates/Dokumente/EN/Kataloge/SparkPlug_GlowPlug_2013_2014_EAST.pdf

In this last link then I found this interesting text on Page 10:

"An HTC
(High Temperature Ceramic) or
NHTC (New High Temperature
Ceramic) glow plug has a heating
element and a heater made
of ceramic.
The NHTC ceramic glow plug was
specially developed by NGK to
enable automobile manufacturers
to comply with the Euro 4 and
Euro 5 emissions standards. One
of the goals of these standards is
to reduce the compression ratio in
diesel engines. NHTC glow plugs
reach a temperature of 1,000 °C
in less than two seconds and
can after-glow for more than
ten minutes at temperatures
of up to 1,350 °C."

This could explain why I sometimes find my engine a little easier to start by waiting a short time after the glow plug light has gone out. Would appear that the glow plug still has some energy to impart to the combustion chamber after the heating current is removed.
 
Resistance below 5 ohms is accepted as good.

See here: http://www.ngk-dpower.com/index.php?id=31&L=2

Also good info here: http://www.ngk.de/fileadmin/templates/Dokumente/EN/Kataloge/SparkPlug_GlowPlug_2013_2014_EAST.pdf

In this last link then I found this interesting text on Page 10:

"An HTC
(High Temperature Ceramic) or
NHTC (New High Temperature
Ceramic) glow plug has a heating
element and a heater made
of ceramic.
The NHTC ceramic glow plug was
specially developed by NGK to
enable automobile manufacturers
to comply with the Euro 4 and
Euro 5 emissions standards. One
of the goals of these standards is
to reduce the compression ratio in
diesel engines. NHTC glow plugs
reach a temperature of 1,000 °C
in less than two seconds and
can after-glow for more than
ten minutes at temperatures
of up to 1,350 °C."

This could explain why I sometimes find my engine a little easier to start by waiting a short time after the glow plug light has gone out. Would appear that the glow plug still has some energy to impart to the combustion chamber after the heating current is removed.

Thanks for the info its really helpful and this means my glow plugs are good and I need to look somewhere else than the heating system.
 
I had a much better post but accidentally lost it on changing tabs in IE (hit rhs of tab by X which closes it)

When I tested my plugs I used a clamp on current meter so that I could actually see the current going into each plug. Just because a plug measure 5 or less ohms does not mean it will draw the appropriate current. If there is a wiring/connection problem (e.g. high resistance due to bad or dirty connections) then the current delivered to the plug will be a lot less, and even possibly zero.

If you don't have a clamp on meter then you will have to test "in-line" instead.

For what it is worth a clamp on current meter/dongle is one of the best tools I've ever bought. Made the wiring of towbars on several cars a complete doddle to locate the correct wire. Likewise for alternator charge/drain measurements etc. etc.
 
just measured my 4 good spares I have.
all 4 were 1.2ohms (at temp of around 5c) and when warmed in hand for 30 seconds or so dropped to 0.8oms.
looking at your figures 2 are drawing nearly 50% less amps than the other 2.
if you've never fitted glow plugs for many years it may be worth doing, as they do stay on in the background even after start up for some time I believe, to help warmup and emmisions and mpg
 
I had a much better post but accidentally lost it on changing tabs in IE (hit rhs of tab by X which closes it)

When I tested my plugs I used a clamp on current meter so that I could actually see the current going into each plug. Just because a plug measure 5 or less ohms does not mean it will draw the appropriate current. If there is a wiring/connection problem (e.g. high resistance due to bad or dirty connections) then the current delivered to the plug will be a lot less, and even possibly zero.

If you don't have a clamp on meter then you will have to test "in-line" instead.

For what it is worth a clamp on current meter/dongle is one of the best tools I've ever bought. Made the wiring of towbars on several cars a complete doddle to locate the correct wire. Likewise for alternator charge/drain measurements etc. etc.

No problems, what you found is more than enough. I was so busy these days at work and I didn't had time to search for nothing. I did measure all of them with a clamp on amp meter, posted the results on the first page of this thread. I did use a contact cleaner for the plugs just to be sure. Who knows, maybe one of them glow plugs gone nuts. I will not worry about it for now, because I'm worried more about why I can't see the injector 1 correction in FES/MES. Thanks again.
 
just measured my 4 good spares I have.
all 4 were 1.2ohms (at temp of around 5c) and when warmed in hand for 30 seconds or so dropped to 0.8oms.
looking at your figures 2 are drawing nearly 50% less amps than the other 2.
if you've never fitted glow plugs for many years it may be worth doing, as they do stay on in the background even after start up for some time I believe, to help warmup and emmisions and mpg

Indeed, two of them draw less current than the other two. Measured with a Fluke clamp on ampere meter and two of them start drawing 19 amps dropping to 7.5 amps in 15 seconds and other two start drawing 13 amps dropping to 6 amps in 15 seconds. Made the measurements with both cold and warm engine and got almost same results. I never changed them, I have the car since last year (19 months) but I see your point.
 
I have played the vid in post 1 a few times and cannot hear an uneven revs, considering its -1 , your battery didn't seem 100% during cranking not supprising if out all night in sub zero, I bet theres plenty of people who wish there car started like this to come over winter.
the revs start at a higher rpm and then slowly reduce 1100,1000,900 down to normal idle rpm dependant on engine /coolant temp.
the tone of idle changes in the middle of you standing away around 1min in video could be car could be your hand on camera, tone changes during the egr cycle.
where in the vid was the erratic idle to wach again?
also the injector correction does sound odd I have never seen a zero on any stilo or alfa thread, maybe its a software issue , worth raising it with yani at fes to see if its a bug?
http://forum.multiecuscan.net/viewforum.php?f=3&sid=1dc7edb0476aea733e9dd93405ae67c7
 
I have played the vid in post 1 a few times and cannot hear an uneven revs, considering its -1 , your battery didn't seem 100% during cranking not supprising if out all night in sub zero, I bet theres plenty of people who wish there car started like this to come over winter.
the revs start at a higher rpm and then slowly reduce 1100,1000,900 down to normal idle rpm dependant on engine /coolant temp.
the tone of idle changes in the middle of you standing away around 1min in video could be car could be your hand on camera, tone changes during the egr cycle.
where in the vid was the erratic idle to wach again?
also the injector correction does sound odd I have never seen a zero on any stilo or alfa thread, maybe its a software issue , worth raising it with yani at fes to see if its a bug?
http://forum.multiecuscan.net/viewforum.php?f=3&sid=1dc7edb0476aea733e9dd93405ae67c7

Erratic is from 0:25 to 0:30, but you can hear it better if you watch the video from page 2 which is filmed from outside and right now I am uploading a new one from outside, but closer. Yes the battery didn't give 100%, car was sitting for 3-4 days, I have charged the battery after that video, but usually, that's her start after sitting few days. The battery was OEM new last year when I bought the car and this year I checked the level of the electrolyte, topped up and fully charged it. Thanks for the MES link, I will put a question about that injector correction. Thing is, I checked another Croma with same engine and it was showing the correction on all injectors with the same software :confused:
 
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