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boost problem

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Between what they "think" they found vs what you think, is a tough one to explain.

It'll be nice if Lotus has ecu loaner, done & over with!

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i just spoke with a service manager for a lotus dealer in Austin, and he is of the same opinion as me, that as long as there is no issue detected with the engine, that the boost should increase above .3 bars by the ECM sending a signal to the wastegate solenoid valve to ventilate the system.

i will be meeting with the lotus service manager this afternoon and get more detail.

i agree with you, it would be nice if there was an ecu loaner to see what happens.

will update the posting as i find out more.

extremely frustrating!!!

i met witht he service manager, and he said that he spoke with David Simkin and Arnie Johnson. their position is that the boost should never exceed .3 bars or 5 lbs of pressure. i showed him the manual where it says that the ECM can request up to .75 bars (11 lbs) of pressure under Wide open throttle, normal operating temp and there is no detonation detected by the knock sensor. he agrees with me that he read the same thing in the manual and told these two gentleman what the manual says, but they still indicate that the ECM will not allow boost above 5 lbs. i then said that I have been the owner of this car for 5 years or so and i have always been able to boost just like it reads in the manual by mashing on the accelerator and getting about .7 to .8 bars of boost on the gauge. he indicated that basically that is because the ECM is "learning" and over time the boost will be restricted to 5 lbs.

we talked about re-setting the software on the ECU since I am beginning to think this may be a software problem. maybe something happened with he software and re-initializing the software takes the system to baseline just like re-booting a personnal computer. (i am probably reaching here). he is going to reset ECU. for anyone interested here is the process.

1. turn ignition on

2. within 10 seconds fully depress the accelerator 7 times.

they do not have a spare ECU to swap.

i am seriously thinking about upgrading my ECU now. we discussed this option also.

if anyone has any input, i am all ears.

thanks

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Hi Francisco,

Interesting information about how to reset the ECU (I'll go and try this tomorrow). I would have expected them to use the "TECH 1" to reset the ECU. I've always gone for the power off method, but they should know.

I'm not convinced by the explanation about the ECU not allowing more than 0.3bar boost. In the days when I ran a standard ECU I also saw boost >0.5bar.

In regard to an ECU swap, is there no one in your neighborhood, who has a 97 V8 Esprit who could let you borrow theirs for an hour? I do appreciate that the USA is a v. large country, so it may not be that convenient.

Thanks for keeping us updated, and I hope it is resolved soon.

Regards,

Peter.

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Nope, don't know anyone that has one that I can borrow. Peter, can you tell me what ECU oyou upgraded to in your exprit, and who you bought it from?

thanks

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That's an interesting ECU reset. First time I heard this one....hmmm could have been an Al Capone secret vault from Lotus.

I'm with Peter...I don't believe the explanation either. We will see what is their next advice.

So, are you going to do the reset or the dealer mechanic? I can't wait if this procedure will work.

I bought my chip to Johan. If you are interested with Johan chip, let me know and I will dig his number. I think he is from Colorado.

Edited by Che

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Shame on Arnie and Dave!

That's the biggest BS story I have heard. I have logged, with my data logger, 11.5 # of barometric corrected boost for over 4 years! There must be some misunderstanding. The manuals are full of .75 bar statements. I have not reset my ECU in several years.

Wayne


The Older I get the Faster I was

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I use Marcus' Red Race ECU see PUK

I'm happy with it. Not sure what the differences between it and Johan's upgrade are. From what I have read both tend to be rich at high boost, but without charge cooling you probably can't risk a leaner A/F.

Regards,

Peter.

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Hi All,

IMHO you received a lot of wrong information.

The mechanical boost is set to 0.35 bar (~ 5 psi) thats the level, you will get when the ECU is doing NOTHING !

Everything above 0.35 bar is controlled/added via ECU. And its done in a quite complicated way upon a lot of parametres and sensor inputs. If everything is 100% you will get these max boost levels with your standard ECU (its gear dependent !):

V8%20Boost%20Standard.jpg

Maximum is 0,75 bar.

Of course, if the ECU is seeing some odd sensor input, then it will reduce max. boost. If one or more values are very "bad" then it will reduce max. boost down to 0.35 bar. (Less than 0.35 bar is not possible, because this is a mechanical thing)

Cheers

Marcus


Marcus

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Eureka

The ECU did reset when I followed Francisco's instructions.

Reset ECU Procedure:

1. turn ignition on

2. within 10 seconds fully depress the accelerator 7 times.

I tested by checking my long term trim values (values were not 0). I then did the above procedure and re-checked the long term trim values. They were reset to 0.

Only downside is that the ECU will have to relearn the correct idle rpm. So if you see a blue Esprit stalling at traffic lights it may be me.

Regards,

Peter.

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Pete nice to know the reset procedure works!

Don't worry about stalling in the traffic light of Launceston or Cornwall or Devon,

Wayne, Francesco and I won't get late to work :)

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Francisco,

I believe either your service manager is lying to you or he is mistaken. I just can't believe that Dave Simkin or Arnie Johnson would have said what he claims about boost being limited to .3 bar by the ECU. Both of those guys know the system in and out and clearly that info is incorrect....


1995 S4s

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i am with you all on this. the more i think about it the more frustrated i get.

i told the service manager yesterday that there is something weird about some sensor that he is not accounting for, the manual is not specific on the algorithm the ECU uses to ensure .75bars of boost can be achieved. i also made the point to him if the car is only designed to provide 5lbs of pressure, then why is there a solenoid on the system connected to the ECU to ventilate the system to allow boosting above mechanical setting.

i am thinking that something is getting lost in the translation through the service manager, i can't imagine that he would be lying to me.

anyway, they will try and reset the ECU today and see what it does. if it does not, i may try and get the contact information to these two gentleman and speak to them myself.

yes, can you email me johan's information regarding the ECU?

thanks

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I do believe that the boost parameters are set to run when all the readiness codes are set... which is why, in Johns car, I had to use an 02 simulator to get full boost and proper afr. The Computer was not setting a CEL, but it was richening the mixture and pulling boost because it had determined that the cat wasn't running efficiently -- which will not, immediately, set a check engine light. Additionally, any check engine light will do the same thing is my understanding... and I've experienced it with Johns car -- because I disconnected the secondary air system, the O2 sensors had detected it's absence and set a CEL... once this CEL was active, my HP went way down.


Modifying esprit's.. now that's fun..

PS... I AM NOT A CERTIFIED MECHANIC.. I Have chosen to help those in need, in the past and must not be construed as being a certified technician.

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Yes.. that's what was happening with Johns car -- I hit 7.8psi boost and a pig-rich 9.8AFR when the secondary o2's were detecting that the catalytic converters weren't there.

--- and that was with the typical o2 "trickers" which pull the 02 sensor out of the exhuast stream so it reads as if the cats are there.. but the exhaust flow was too high and it wasn't being effective enough... I eventually got a CEL... but it took quite a while.

oh yeah... now i've installed a manual boost controller on his car.. spikes to just below 12 psi and levels at 10... works like a charm! I no longer have to worry about silly computer things... lol.. however, it means you must be much more cautious about driving the car... no hard acceleration in first, no hard acceleration at all untill you're up to engine temp etc...


Modifying esprit's.. now that's fun..

PS... I AM NOT A CERTIFIED MECHANIC.. I Have chosen to help those in need, in the past and must not be construed as being a certified technician.

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interesting.

prior to the problem appearing, i replaced the stock exhaust with a stainless steel stebro exhaust. i did not change the cat converters, they are still there. when this problem appeared i first thought that it was my new exhaust that was causing the problem. i then removed the new exhaust and installed the stock exhaust. the problem with the boost was still there with the old exhaust, so i elimitated the new exhaust as the culprit.

can you give me some things to do to see if the secondary O2 sensors are causing the problem?

thanks

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fraancisco, haven't we spoken about the O2-sensors and how you can determine what those do. All four are the same, so you can swap rear one with front and vice versa. Use some OBD reader to see what voltage levels you get on cold-start, moderate run and 'full boost' -or WOT with other words..

And you can inspect your catalyst elements with an doctors light an mirror along the sensor mounting holes... . :)


*********************************************************************

to name the things if I see them, that's what I call integrity..

*********************************************************************

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there has been so much discussion here that it's hard to remember what all has been discussed. anyway, i just reviewed all the posts and did not see a reference to the oxygen senson specifically.

i will try to speak to the service manager again to see if he is changing his position that the system is working as designed. if they stick to this position and give me the car back without looking at this further, then I will start focusing on the oxygen sensors specifically.

thanks for the post

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It's as so many members ask the same things: how can i get information from my sensors, how do they akt where are those sensors, what type of catalyst does fit my engine and so on...


*********************************************************************

to name the things if I see them, that's what I call integrity..

*********************************************************************

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The other thing I should mention is that since you are able to reach 0 psi of boost you have a different problem with you're turbo setup... I have no doubt about this... the reason I know this is that 15 psi comes EXTREMELY quick if you disconnect you're vacuum lines to the wastegates... if you step on it in second gear, with the wastegate lines disconnected at WOT.. you should hit 15 psi and the pressure relief valve should activate by about 4200-4500rpm. So if you've run it without the wastegate lines connected and you haven't experienced this.. then you've got spool issues.. which to me is still a clogged catalytic converter.. which is why you're computer is going into limp mode and not giving you further boost control in the first place..


Modifying esprit's.. now that's fun..

PS... I AM NOT A CERTIFIED MECHANIC.. I Have chosen to help those in need, in the past and must not be construed as being a certified technician.

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Francisco,

I've put a few suggestions below. You or the mechanics may have already covered them.

Have you or the Lotus mechanic checked the system tests after the car has 'warmed up'?

OBD system tests are:

Misfire

Fuel System

Components

Reserved

Catalyst

Heated Catalyst

Evaporative System

Secondary Air System

A/C Refrigerant

Oxygen Sensor

Oxygen Sensor Heater

EGR System

Please note that not all tests are available on the V8 Esprit. The important ones in regard to the O2 sensors are the "Oxygen Sensor" & "Oxygen Sensor Heater"; Check that these have 'Passed'.

Also use the OBDII scanner to check that the O2 sensor reading for all 4 O2 sensors. The voltage readings should switch between a high of about 0.9v and a low of 0.1v. If the sensor

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thanks peter,

i checked alot of these myself prior to bringing into the shop. the mechanic told me that they checked most of the items above, but frankly i did not go item by item above, it was in conversation. i am planning on talking to him today to see if he has reset the ECU.

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I just found a nice table in the service manual (Section EMM2 - Page 2) that lists what parameters/sensors are used by the varies control systems. For Boost Control it list the following parameters/sensors:

- Engine Speed

- MAP

- Baro

- Throttle Position

- Coolant Temp

- Inlet Air Temp

- Knock Sensor

- Wheel Speed

Might be worth asking the mechanic if they have looked into all of the above.

Your poor mechanic will probably be mighty pissed with all this amateur fault finding. However, as he hasn't fixed the problem, he probably is asking for it.

Regards,

Peter.

Edited by peter_england99

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just spoke with the service manager:

1. they reset the ECU and problem persists

2. he is trying to contact Arnie again to get confirmation on the 5lbs of pressure issue which we all disagree with.

3. we also talked about upgrading the ECU to a chip from PUK engineering, and he says this will definitely make the boost issue go away.

will wait and see what he gets from Arnie.

does anyone know if there is a tech support or contact at Lotus in England that I can contact?

thanks

thanks peter,

i actually showed him this table, and he stepped through it and says that it all looks good.

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Francisco,

Member brian_gt4 is very well connected in regard to Esprits (I think Gunter already recommended contacting him). A PM to him might be useful.

Regards,

Peter.

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