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Passmore928

Freescan file - Boost issues

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Hi LEF users,

I introduced myself yesterday to the forum:
http://www.thelotusforums.com/forums/index.php?/topic/33361-an-introduction/'>[url=http://www.thelotusforums.com/forums/index.php?/forum/15-introductions/?quot;]

I have attached a freescan run of my car. I have a few points for any input if possible. I'm a little worried about the level of boost I'm achieving.
You can see that mapping points at high rpm are almost exclusively ca. 2.25bar. It is also of note that the Air/Fuel ratio really drops off when I hit 2.25bar.
Obviously the wastegate can't be moving correctly. Now I read that a 2.25 value on freescan = ca. 1.1 bar real boost. However, this is still higher than it should be, and anyway the range of the pressure sensor hits it's limit at 2.25 so I can't see how far it's going above that!

So I reckon I have either:

Incorrectly adjusted wastegate (or corroded shut due to age)
Broken solenoid that is constantly venting the pressure sensing line (although you would expect this to fail in the de-energised position)
Leaking or disconnected pressure sensing lines.

As far as I can see it can literally be only these things. There is no other way of building that much boost - or am I missing anything?
Am I correct in thinking that if the ECU detects too much boost it kills the fuel pump / ignition resulting in a hard stutter.
This has happened to me a few times, however, not on this run unfortunately.....and is obviously a sign things are not right!

I see the Wastegate DC and also Secondary Injector DC are never at 1.
Also is my MAT a bit high?
hmmmmm, maybe I wrote too much already.....Any input greatly appreciated.

cheers,

Andy

p.s. a big thanks to all on here for all the posts and help I've used so far just by reading! Freescan and Espritmon are just the best tools.
 

run home.xls

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Hi Andy - welcome to the forum :cheers:

I did a little real time chart of boost vs freescan MAP here :

http://www.flickr.com/photos/jonhimself/3698222359/in/set-72157623278905153/

Where are you located ? I notitced the Barometer reading is low (the Alps ?), you're static MAP pressure should also be about 0.56 at idle, I'm guessing altitude might have an affect on this.

The A:F will drop off as the boost rises, which is why I believe there are secondary injectors to help with the fuel delivery, the A:F and the O2 sensor readings on this scan look fine.

Whats not good is the MAT or the chargecooler, what it the ambient air temperature where you are ? A good system at 20C ambient should not go over 30C and only peak at 40 on extended max turbo boost (ie for more than 10 seconds) - your MAT is WAY too high, and is what is causing the knocking I would have imagined. I dont think this is down to excessive boost either, I would check the impeller and replace if necessary with an electric pump - common fault.

The Wastegate imo is incorrectly set, you're achieving high levels of boost without any wastegate DC (overboost solenoid which is an ECU boost controller)

I notice you also have a code 26 fault, this is likely to be the wastegate solenoid broken or open circuit.

For reference the car should achieve 0.65bar of boost on the pushrod only (called mechanical boost), with the wastegate solenoid connected it should get 0.85 bar (or freescan reading of just uner 2.0)

I would investigate the Wastegate solenoid and the code 26 fault 1st.

Then get a compressor and known pressure gauage and re-set the wastegate actuator arm or replace.

See what the ECU makes of it after then.

As I say the MAT temp is likely to be a busted pump impeller.

Edited by Jonathan

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Thanks for the feedback. Appreciated.

When I did that run I was not in the mountains, but still at ca. 2000ft.
Using espritmon last night to double check the sensor I got a reading of 0.93, which whilst a little low, is not massively out.

I'll investigate the MAT, I'd suspected it might have been running high but had no idea I was 40°C high!
Ambient temp on that run was ca. 18°C. So reaching >70°c is certainly not good.
The car has previously been converted to an electric pump, but clearly I need to check it's working!

I agree regarding the wastegate being incorrectly set.
As a precaution I have ordered a new wastegate, wastegate solenoid and all connecting pipes / elbows. Should be here next week.

However, as to the wastegate solenoid driving my code 26 I'm not so sure.
Espritmon says quad driver circuit B is generating the fault. i.e.

RPM Relay
AC control relay
Engine overheat relay
Throttle jack solenoid
Secondary injectors

Do you have any advice / methods to trouble shoot these?
Am I correct to ignore the AC control relay and Engine overheat relay on a GT3 with no Aircon?

cheers,

Andy


 

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Be careful with code 26, I dunno if Espritmon changed the flag but with Freescan the code 26 A can actually flag a Code 26 B so be sure before you write stuff off - seen many a person tear their hair out over this, chasing a fault that isn't there !

A fuse in the circuit can also be the cause (preventing the relay) so check those.

Aircon relays and fuse have to be in iirc, mine definatly flags a fault if I take mine out.

Engine overheat is just that so dont write that off either.

My 1st check would be the secondary injectors, this is actually a large balast resistor not a relay (~330 ohms) so take that out and meter across it, keep in mind you also have no activity on the seconday injecotrs on the freescan file so that might be the issue. You might want to check the secondary injectors too, not just the connectors.

When the car is switched on the secondary injectors are always live, the ECU grounds the neutral to complete the circuit so they fire - so a simple voltage check to earth from the injectors will prove the circuit is either working or not.

You would do well to grab a user manaul / wiring diagram if you're going to delve into fault finding that much.

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Regarding the ballast resistor, I don't think it is 330 Ohm. In the scanned Lotus manual it seems like a decimal point has disappeared, but it should be 3.30 Ohm

Erik

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Morning Gents,

Back in CH, so I had a go at chasing faults on the GT3 yesterday.

Success:

Electric chargecooler pump now in operation - now properly wired into EBPV circuit with a new fused relay.

MAT down at ca. 10°C - 15°C above ambient.

New wategate actuator, wastegate solenoid and all connecting pipes replaced.

MAP not breaching sensor limit anymore, however I feel it needs a bit of actuator fine tuning to bring the boost up a bit.

Max MAP is at ca. 1.7 bar looking at espritmon (Erik - what does this mean in the real world? - are espritmon figs 'real' i.e. corrected unlike freescan?)

ABS fault identified using espritmon - front RH wheel sensor defective. New one ordered.

Failure:

Code 26 'B' still eluding me!! I removed the covers of all relays and then plugged them all back in so you could see the internals moving when individually triggered with espritmon.

AC control relay : Working

Throttle jack solenoid : Working

Wastegate solenoid : Working

RPM Relay : Unsure of function. Will move when triggered by espritmon but then stays in position - i.e. does not move back. I swapped relays with ones that were working, always the same situation - is this correct?

Engine overheat relay : Where is this? Is this fitted to the GT3?

Secondary injectors : 3.3 ohm measured at resistor. Injectors 'appear' to be working - espritmon shows activity during recorded runs - whether both are active is unknown....

any suggestions?

cheers,

Andy

Edited by Passmore928

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Hi Andy,

Regarding the secondary injector resistor, you mention that you verified that the resistor is 3.3 Ohm. However, if there is somehow a loose connection between the resistor and the secondary injectors or between the secondary injectors and terminal J3C13 of the ECU, the ECU will not 'sense' the +12V at J3C13 and set code 26.

Regarding the RPM relay, it is engaged by the ECU above 1500 RPM. If you start the car when the engine is warm and the reference RPM is below 1500 RPM, and code 26 is set within the first 20 seconds of the engine running, you can rule out the RPM relay (because under these conditions the ECU never tried to engage it). Also, if the AC is not engaged, you can rule out the AC relay.

I looked at an older Espritmon logging in which I had the problem with the secondary injector resistor and at startup the QDM B light stays on, and at engine run time 23 seconds the CEL goes active.

Hope this helps you to narrow down the possible causes,

Good luck,

Erik

p.s. the fact that Espritmon shows the 2ndary injectors active only indicates that the ECU commands them on, not whether they actually are on.

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Engine check light working? For certain?

As I recently discovered this'll throw code 26

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When the Check Engine Light is broken, the code 26 will yield QDM A to be on, not QDM B.

Erik

p.s. just realized that Andy provided the info about QDM B in another thread.

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I made a mistake when saying that you can rule out the RPM and AC relay when they are not yet engaged. The ECU also tests for an open circuit when not activating relais and solenoids. However, if the code 26 occurs already just after the first 20 seconds of engine running (so the fault is immediately present at startup), the relais / solenoids that can still be activated using the menu in Espritmon are very likely not causing the problem.

Sorry for the confusion that may have been caused by my previous remark.

Hi Andy,

Regarding the secondary injector resistor, you mention that you verified that the resistor is 3.3 Ohm. However, if there is somehow a loose connection between the resistor and the secondary injectors or between the secondary injectors and terminal J3C13 of the ECU, the ECU will not 'sense' the +12V at J3C13 and set code 26.

Regarding the RPM relay, it is engaged by the ECU above 1500 RPM. If you start the car when the engine is warm and the reference RPM is below 1500 RPM, and code 26 is set within the first 20 seconds of the engine running, you can rule out the RPM relay (because under these conditions the ECU never tried to engage it). Also, if the AC is not engaged, you can rule out the AC relay.

I looked at an older Espritmon logging in which I had the problem with the secondary injector resistor and at startup the QDM B light stays on, and at engine run time 23 seconds the CEL goes active.

Hope this helps you to narrow down the possible causes,

Good luck,

Erik

p.s. the fact that Espritmon shows the 2ndary injectors active only indicates that the ECU commands them on, not whether they actually are on.

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Ok, good luck. One final remark. I'm not familiar with the exact setup in the GT3, but given that it is even newer than the revised harness S4, there is one important difference between the QDM B causes relative to the older S4 and SE models. One of the five potential causes for the QDM B is the 'engine overheat relais'. However, in the revised wiring harness cars, this relay is no longer present. In the right schematics you will see that output J1A3 is directly connected to the overheat warning light in the dashboard. To my knowledge this was never updated in Section EMH.4. So, if this light is broken in a car with this setup, you will also get a code 26!

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Well I am ashamed to say I could not trace the code 26 at the weekend.
The end result is I dropped the Esprit into my local Lotus dealer yesterday. They have now come back and said my ECU is broken.
This was verified by swapping it with another GT3 ECU they have on site.

Now, can anyone recommend anywhere where this can be sent for repair? Is this possible?
I'd rather avoid the purchase of a new one!

cheers,

Andy


 

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Right, time for an update.

In the end I bought a new ECU from South West Lotus Centre.
This was actually far cheaper than having it repaired by Bluestreak, who quoted over £400 - the brand new one cost £220 including shipping to Switzerland.

So, new ECU arrived quickly, the memcal was swapped from the old ECU to the new.
Plugged in, and everything now works! No Code 26!

cheers for all the help!

Andy


 

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