Technical ECU Testing/Repairing In UK?
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Technical ECU Testing/Repairing In UK?
Hi again.
Throttling the airflow...
could be that the MAF isnt reading.. and you are actually dragging the airflow down to the fuelling level (to match what the ECU is calculating..from its various inputs)
Have a good look at ALL the values associated with combustion..
This issue isnt dissimilar to my 1st experience of ECUs being tested..repaired..then replaced
All to no avail
That cost @£3k.. fingers more than singed..
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Hi Charlie,Hi again.
Throttling the airflow...
could be that the MAF isnt reading.. and you are actually dragging the airflow down to the fuelling level (to match what the ECU is calculating..from its various inputs)
Have a good look at ALL the values associated with combustion..
This issue isnt dissimilar to my 1st experience of ECUs being tested..repaired..then replaced
All to no avail
That cost @£3k.. fingers more than singed..
Thank you, I hadn't considered that.
Do you think the op can look at injection time in milliseconds and see if that changes when he puts his hand over air inlet?
Or look at air flow in grms/sec and see if it changes with increasing rpm?
£3k eeek
Cheers
Jack
Tbh..
Ive not performed any of the 'live data'
But airflow should be there..
I would just check basic function 1st though
Engine and air temps should be pretty obvious..
That -37'c is a standard 'low'
Air will be 15/20 as will coolant and fuel
Ive not performed any of the 'live data'
But airflow should be there..
I would just check basic function 1st though
Engine and air temps should be pretty obvious..
That -37'c is a standard 'low'
Air will be 15/20 as will coolant and fuel
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Most of my MES work was with an 04 panda..
All Bosch .. mow look at Punto diesels..all Marelli
so could be TOTALLY different to the Hitachi ..irrespective of build dates
minimayhem
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Fuel filter has been replaced, pump has been uprated with a 255pl unit. Fuel pressure is strong, been tested and running all good.
Regarding covering the throttle body - if I remove the intake system entirely to the throttle body mesh, then cover half of that, the car idles out perfectly and runs fine. I'm just thinking that if the car thinks its running lean, and is reducing fuel to match a lean burn, then covering the throttle body is restricting the air intake to even out the air/fuel ratio.
The MAF was swapped out to no avail. If I cover the MAF the car dies completely. I also cleaned the IACV, and that was swapped out to no avail too.
I've also replaced the thermostat.
I'll crack out my laptop tomorrow and run a series of checks from cold to hot. Will get some graphs runing and check all the components, sensors that manage air/fuel ratios.
The problem has to lie somewhere!
Regarding covering the throttle body - if I remove the intake system entirely to the throttle body mesh, then cover half of that, the car idles out perfectly and runs fine. I'm just thinking that if the car thinks its running lean, and is reducing fuel to match a lean burn, then covering the throttle body is restricting the air intake to even out the air/fuel ratio.
The MAF was swapped out to no avail. If I cover the MAF the car dies completely. I also cleaned the IACV, and that was swapped out to no avail too.
I've also replaced the thermostat.
I'll crack out my laptop tomorrow and run a series of checks from cold to hot. Will get some graphs runing and check all the components, sensors that manage air/fuel ratios.
The problem has to lie somewhere!
If you remove the intake pipework including the maf sensor to partially cover air to throttle body you have removed the sensor that ecu uses to calculate how much air is being drawn in.
Yes the problem has to lie somewhere.
Was fuel pressure at fuel rail measured with a gauge?
Fuel pressure regulator not leaking into vacuum pipe?
minimayhem
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The MAF on my car is housed inside the throttle body, so I'm able to partially block the intake while leaving the air going through the MAF unimpeded.
Fuel pressure was measured by an inline pressure gauge rather than using the plug at the end of the fuel rail.
And yeah on the fuel pump that's what I meant - the filter attached directly to it and was replaced along with the pump about a year ago.
Fuel pressure was measured by an inline pressure gauge rather than using the plug at the end of the fuel rail.
And yeah on the fuel pump that's what I meant - the filter attached directly to it and was replaced along with the pump about a year ago.
Did in line gauge show 60psi
Engine running?
Could you please post a pic of throttle body maf, I'm interested (-:
What year is your car?
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minimayhem
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My car is a 98 LE, so has the plastic intake, ECU mounted on the back of the engine, with MAF inside the TB. Sort of a half-way-house between engine revisions.
Sure, here's my throttle body, the 3 pin connector to the right is the MAF sensor:
https://i.imgur.com/Sg5lGkO.jpg
I'm running a GSR setup off the throttle body, so all the stock gubbins have been removed:
https://i.imgur.com/NTvnoDv.jpg
Alrighty, so I've spent the morning running checks over the car and creating some graphs using mes. Here's what I found....
Everything connected (car running rough)
Engine temp sensor voltage - Ranges from 1.365v to 1.460v
Engine temp sensor reading (degrees) - 73 to 75
Lambda sensor voltage - 0.2 to 0.3
Airflow meter voltage - 1.725 to 1.570
When the car hunts/misfires, the lambda sensor drops to 0.2 and airflow increase to 1.725. I'm thinking that this is indicative of the car sensing is going very lean, and trying enrich the mixture by increasing airflow.
Temp sensor disconnected (car running fine)
Engine temp sensor voltage - Steady 4.875
Engine temp sensor reading (degrees) - A very quick dip to -38 then increase to 31, with gradual increase in 1 degrees per 6 seconds
Lambda sensor voltage - Steady 0.3
Airflow meter voltage - 1.690 to 1.745
Temp sensor disconnected (car running rough)
Engine temp sensor voltage - Steady 4.875
Engine temp sensor reading (degrees) - 60, with increase of 1 degrees per 6 seconds
Lambda sensor voltage - Steady 0.2
Airflow meter voltage - 1.585 to 1.700
Temp sensor disconnected & intake covered by around 80% (car running fine)
Engine temp sensor voltage - Steady 4.875
Engine temp sensor reading (degrees) - Steady 80 degrees
Lambda sensor voltage - 0.8 to 0.1
Airflow meter voltage - 1.5 to 1.656
Temp sensor connected and intake covered by around 80% (car running fine)
Engine temp sensor voltage - Steady 1.045
Engine temp sensor reading (degrees) - Steady 86
Lambda sensor voltage - 0.8 to 0.1
Airflow meter voltage - 1.5 to 1.656
OK so what I think this means is that:
1) When the cars temp sensor is disconnected, the ECU goes to -38 and then attempts to estimate the engine temp and simulates increasing temp until it reaches operating temp of 80 degrees. It would be amazing if someone could confirm this behaviour with their car!!!
2) The lambda sensor is operating correctly, as when the intake is covered it bounces bewteen lean and rich, which is expected (from what I've read, please correct me if I'm wrong!)
3) I do still think its an electrical issue, because the car ran fine for around 160 seconds once the coolant temp sensor was disconnected. If the fuel pressure is fine (60 psi mentioned by DTR during testing, both when the car is running fine and when it isnt, measured inline by the fuel pipe running past the coolant resevouir), then something is telling the injectors to have a reduced flow, which is being detected by the lambda. If it was a mechnical issue with say the fuel rail being partially blocked, the issue would not be intermittent.
I'm going to go outside again and run some tests with the injectors....back soon!
Sure, here's my throttle body, the 3 pin connector to the right is the MAF sensor:
https://i.imgur.com/Sg5lGkO.jpg
I'm running a GSR setup off the throttle body, so all the stock gubbins have been removed:
https://i.imgur.com/NTvnoDv.jpg
Alrighty, so I've spent the morning running checks over the car and creating some graphs using mes. Here's what I found....
Everything connected (car running rough)
Engine temp sensor voltage - Ranges from 1.365v to 1.460v
Engine temp sensor reading (degrees) - 73 to 75
Lambda sensor voltage - 0.2 to 0.3
Airflow meter voltage - 1.725 to 1.570
When the car hunts/misfires, the lambda sensor drops to 0.2 and airflow increase to 1.725. I'm thinking that this is indicative of the car sensing is going very lean, and trying enrich the mixture by increasing airflow.
Temp sensor disconnected (car running fine)
Engine temp sensor voltage - Steady 4.875
Engine temp sensor reading (degrees) - A very quick dip to -38 then increase to 31, with gradual increase in 1 degrees per 6 seconds
Lambda sensor voltage - Steady 0.3
Airflow meter voltage - 1.690 to 1.745
Temp sensor disconnected (car running rough)
Engine temp sensor voltage - Steady 4.875
Engine temp sensor reading (degrees) - 60, with increase of 1 degrees per 6 seconds
Lambda sensor voltage - Steady 0.2
Airflow meter voltage - 1.585 to 1.700
Temp sensor disconnected & intake covered by around 80% (car running fine)
Engine temp sensor voltage - Steady 4.875
Engine temp sensor reading (degrees) - Steady 80 degrees
Lambda sensor voltage - 0.8 to 0.1
Airflow meter voltage - 1.5 to 1.656
Temp sensor connected and intake covered by around 80% (car running fine)
Engine temp sensor voltage - Steady 1.045
Engine temp sensor reading (degrees) - Steady 86
Lambda sensor voltage - 0.8 to 0.1
Airflow meter voltage - 1.5 to 1.656
OK so what I think this means is that:
1) When the cars temp sensor is disconnected, the ECU goes to -38 and then attempts to estimate the engine temp and simulates increasing temp until it reaches operating temp of 80 degrees. It would be amazing if someone could confirm this behaviour with their car!!!
2) The lambda sensor is operating correctly, as when the intake is covered it bounces bewteen lean and rich, which is expected (from what I've read, please correct me if I'm wrong!)
3) I do still think its an electrical issue, because the car ran fine for around 160 seconds once the coolant temp sensor was disconnected. If the fuel pressure is fine (60 psi mentioned by DTR during testing, both when the car is running fine and when it isnt, measured inline by the fuel pipe running past the coolant resevouir), then something is telling the injectors to have a reduced flow, which is being detected by the lambda. If it was a mechnical issue with say the fuel rail being partially blocked, the issue would not be intermittent.
I'm going to go outside again and run some tests with the injectors....back soon!
Have you tried replacing the temp sensor? Could it be that simple?
Ideally, you should watch the engine temp readings froma cold start. Initially engine temp should be close to the outside temp and rise gradually as the engine warms up. That is what you will see if the temp sensor is working ok.
On some engines there are two temp sensors. One just works the temp gauge in the car, the other is used by the engine management. Check you are attacking the right one if two are fitted.
Ideally, you should watch the engine temp readings froma cold start. Initially engine temp should be close to the outside temp and rise gradually as the engine warms up. That is what you will see if the temp sensor is working ok.
On some engines there are two temp sensors. One just works the temp gauge in the car, the other is used by the engine management. Check you are attacking the right one if two are fitted.
I asked op to warm up car watching coolant temp sensor degree reading to see if it was smooth with no drop outs. Possibly graph it too.
Dtr changed a load of expensive parts but not the coolant sensor!!!!!.
Fingers xed we are starting to get somewhere.
The ecu can only alter the air fuel ratio (rich or lean) by increasing or decreasing the length of time the injectors are open for.
That is to say increasing or decreasing fuel.
The ecu does not increase or decrease air into engine to alter air fuel ratio.
The ecu only attempts to alter the air fuel ratio when it is in closed loop operation.
The above is very important in trying to understand what is happening.
That is to say increasing or decreasing fuel.
The ecu does not increase or decrease air into engine to alter air fuel ratio.
The ecu only attempts to alter the air fuel ratio when it is in closed loop operation.
The above is very important in trying to understand what is happening.
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minimayhem
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Hi all,
First thing I did this morning was connect to the ECU and monitor the temp sensor reading, it was 2 degrees warmer than air temp (going by bbc weather anyway) which doesn't surprise me as it's very sunny at the moment!
It gradually increased, I didn't see any drop outs but I didn't graph it. I'll do that a bit later though, once the engine has cooled.
When I was last out there I checked the injector time. I don't have the results, will post them later, but there was a marked decrease in time when the engine was running well with the intake partially covered. Timing advance was bouncing around when idling rough, but smooth out once idling properly.
One thing I noticed is that the 02 sensor was sitting in open loop mode when idling rough, which is odd. When the car idled properly it settled into a closed loop mode.
I'm just about to go grab a coolant temp sensor from my local parts shop. For the sake of 18 quid for a Bosch unit it's worth a punt. The old one looks bloody awful.
First thing I did this morning was connect to the ECU and monitor the temp sensor reading, it was 2 degrees warmer than air temp (going by bbc weather anyway) which doesn't surprise me as it's very sunny at the moment!
It gradually increased, I didn't see any drop outs but I didn't graph it. I'll do that a bit later though, once the engine has cooled.
When I was last out there I checked the injector time. I don't have the results, will post them later, but there was a marked decrease in time when the engine was running well with the intake partially covered. Timing advance was bouncing around when idling rough, but smooth out once idling properly.
One thing I noticed is that the 02 sensor was sitting in open loop mode when idling rough, which is odd. When the car idled properly it settled into a closed loop mode.
I'm just about to go grab a coolant temp sensor from my local parts shop. For the sake of 18 quid for a Bosch unit it's worth a punt. The old one looks bloody awful.
minimayhem
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And the results are in - monitoring from cold the coolant temp rises steadily with no sudden drops or spikes in either temp or voltage. The autofactors had the wrong part in stock (2 pin vs 3 pin of which I need the latter) so I've ordered a replacement from an online vendor in the hopes that for some reason its the cause of the issue. It'll be here on Wednesday.
I also replaced the 02 sensor today, the old one was only on finger tight! No change however, issue still remains.
If I disconnect the MAF sensor when the engine is running the engine dies right away.
Something is keeping the ECU in open loop mode at idle unless I cover the intake. It goes into closed loop with the intake covered by 80%, or when I apply throttle.
I also replaced the 02 sensor today, the old one was only on finger tight! No change however, issue still remains.
If I disconnect the MAF sensor when the engine is running the engine dies right away.
Something is keeping the ECU in open loop mode at idle unless I cover the intake. It goes into closed loop with the intake covered by 80%, or when I apply throttle.
Could this be down to a bad throttle position switch / sensor?
Good call on o2 sensor , I hope it's not a universal Chinese one?
Thanks for all your updates .
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