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Qavion

Check Engine Light but no faults in Freescan

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The Direct Ignition Module sends a signal to the ECM for synchronising fuel injection. 5volt square wave signals are sent to the ECM once every engine revolution (as sensed by the flywheel sensor). The signal goes to pin C11 on plug J3 of the ECM. Because it's a square wave, there is some averaging (The digital voltmeter just has to read above zero for it to be ok).

 

If there are no signals sent to the ECM after a certain number of engine revolutions, Code 41 is set.

 

The fault message suggests to me that the problem is the flywheel speed sensor, but I don't know how the message could be set if there is no signal from the flywheel sensor (to measure engine revolutions). Also, the manual doesn't suggest changing the sensor.

 

The manual says it could be the Direct Ignition Module, ECM or interconnecting wire.

 

Experts?

Edited by Qavion

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Bogle,

 

I just replied to your email with your previous freescan data.

 

What have you replaced since then? 

 

IF you replaced the ECU, did you make sure to disconnect the battery first?

 

Did you replace the plate behind the coils?  That is usually the case for the code 41.

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Yes, the battery was disconnected before swapping the ECU.

 

No, we did not replace the plate behind the coils - just the coils.  Should we replace the plate?

 

I'm going to be order more parts today after catching up on work.

 

Thank again for all your help.

 

Bill

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The D.I. module plate behind the coils is Lotusa specific in that if you replace it with a GM D.I. module, then you will get the CODE 41.

 

Read more here

http://www.lotustalk.com/forums/f164/lotus-esprit-parts-cross-reference-110965/index3.html#post3520737

 

It's more likely that you have a wiring issue.

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Can someone tell me where I can find the EMH (Engine Management Handbook or Manual)?  I don't think my Lotus Workshop manual has this information.  All I have is Lotus Service Notes which is helpful to a point, but it doesn't list the error codes.

 

Thank you,
Bill

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Okay,  here's the latest.

 

Replaced DI module, Pressure regulator valve, charcoal canister, O2 sensor, fuel filter, plug wires, spark plugs, coils and ECM.  Oh, the new throttle cable in which the abutment screw needed modification to retro fit the obsolete A version part with a C version part.

 

What's the difference so far...  the car was idling rough, rich fuel smell and turbo lag.

 

Once the pressure regulator value was replaced the fuel smell disappeared.  Still rough idling.

Once the O2 sensor was replaced the idling was improved a little bit.

Once the DI module and charcoal canister were replaced the idling appears to be almost normal at 1050 to 1100 rpms.

 

We got the DI module and Charcoal Canister in late last night.  I decided to take it out to see if it was still running in limp mode and yes it still is running that way.  The CEL light is still on. Unfortunately, I was too tired to hook up Freescan. 

No back firing (it's never done that).  When I step on the gas I get nothing and it takes forever to get the RPM up.  The turbo is not engaging since it's in limp mode.  Stepping on the gas it hesitates and can stall easily.  Gotta ease into the pedal just right while engaging first gear.

 

Next step is to replace the fuel pump.  I misread the manual and originally thought it was necessary to remove the rear 1/4 glass panel.  I missed the word trim.  Although it would be easier to do work on fuel pump without the glass.  To remove the top part of the fuel pump (retaining ring component) - are there any suggestions as to the best access to get to remove that retainer?  sitting in the boot? etc?

 

Does anyone know where I can get a pressure checker which connects to the pressure regulator valve?  Is that strictly a Lotus part or can I get it at Auto Zone/Napa store?  Is that a metric thread or standard on the port?

 

One of these days, the car will ride again...I'm now at 5 months since maintenance started.

 

Thanks again as always

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are there any suggestions as to the best access to get to remove that retainer?  sitting in the boot? etc?

 

 

I'm sure I did my last one just by leaning over the side of the car (but then I do have long arms). The hatch strut might get in the way. My last pump came out pretty easily, but perhaps I just used the right combo of tools (long large flat screwdrivers/rubber mallet) and remembered when to "lever" and when to "bash" on the locking ring. Officially, you're supposed to use non-sparking tools. From memory, there are two strike points. I think it's easier to alternate between the two (and only move them a little at a time). I'm not sure if WD40 will help. It might just make your tools slip off more easily. Perhaps a light spray on the surfaces for next time.

 

Finding the right sized fuel-resistant o-rings for the pipes can sometimes be a little tricky. Nitrile or similar.

 

Does anyone know where I can get a pressure checker which connects to the pressure regulator valve?

 

 

I think I bought a cheap pressure checker from eBay which came with an adaptor hose kit. UKP20 or less. It's one of the standard sizes.

 

 

I've forgotten. Did you change the Throttle Position Sensor (TPS)?

 

Cheers

Ian.

 

(EDIT: usually the rubber rawlnuts/ well nuts which hold on your quarter panel will be damaged. They are available online. You may even find some at your local motorbike parts store. Sometimes they are used on motorbike windscreens.

Edited by Qavion

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That would be a no on the Throttle Positioning Sensor and the only one I didn't order on Tuesday.  Do you think I need one possibly?

 

I have the MAP, barometric, IAC and Flywheel sensor coming in on Friday.  I'll try to replace the fuel pump tomorrow night.

 

My plan is to replace the Fuel Pump and run Freescan to check the codes afterwards.  Travis recommended replacing the fuel pump due to age (25 years plus) and the pulsation part issue.

 

I'm getting tired of waiting so I just order the parts so they are available if I really need them.

 

 

 

Thank Ian for replying so quickly.

Bill

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That would be a no on the Throttle Positioning Sensor and the only one I didn't order on Tuesday.  Do you think I need one possibly?

 

 

There is similar message thread running on the forum posted by "Ginger pig". I sometimes lose track of who is who. Some of the symptoms are similar. Freescan should tell you if your TPS is ok, although the TPS, from what I hear, is not built to high tolerances.

 

See this thread:

http://www.thelotusforums.com/forums/topic/76162-turbo-se-engine-stalling/

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Do the iac valve first.......

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The new IAC is having some issues learning since putting it on.  Car is attempting to idle at 450 rpm instead of 1,000 to 1,100 rpms.

Tried to put a new TPS, but it didn't work - read 0 across in the Sensor Logs.  Put the old one back on and at least it's reading via Freescan.

 

Freescan is still throwing a Error 41 Engine Speed Signal Missing.

 

I can drive it around as long as I can keep my foot on the gas pedal to stop it from stalling.  It appears the high rpms are working fine and boost is working as well.  It's just when I come to stop that it will stall if I'm not careful on the gas pedal.

 

We will be following the Poor Idle steps and if necessary might need to manually adjust the throttle air bypass.  Got the battery disconnected and letting it cool down before trying to get this IAC issue resolved.  Seems like we are close to getting it back on the road, but not sure if I'm need to put back on the original Coils and DI Module to get rid of the Error 41 or not yet?

Edited by bogle

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Weird. I can't believe you're having so much trouble with this, Bill. Faulty new TPS.. and who knows.. maybe even a faulty new IAC. When you change an IAC, you may have to put the accelerator pedal half way down when you start the engine and slowly back off. Why it still wants to hold 450rpm, I don't know.

Having said that, when I changed my ECU, the car ran terribly the first time. But the next day all seemed fine. Perhaps you just need to wait a day? :)

 

@Travis. Is the Error 41 message just a nuisance message or might it cause this problem?

 

I noticed yesterday that my car almost stalled when I pushed on the pedal in the driveway after start up (no load). I might order a new IAC and check my TPS on Freescan. I'll try the recommended Airtex/Wells brand IAC this time from RockAuto.

 

Cheers

Ian.

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Make sure the iac is the correct one. The one in the parts cross ref is the wrong number for my car and caused a whole heap of errors.....

The shape of the pintle (bit at the end) is absolutely critical - must be the same.

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Make sure the iac is the correct one. The one in the parts cross ref is the wrong number for my car and caused a whole heap of errors.....

 

 

Hopefully I ordered the right one. I got some of the alternate numbers from this thread:

 

http://www.thelotusforums.com/forums/topic/74755-air-idle-control-valve/

 

Rockauto says that the Airtex/Wells 2H1042 is an equivalent

 

Thanks

Cheers

Ian.

Edited by Qavion

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Good luck with it....... If it's the wrong one you will know. Filled my garage with lots of co ( always have an alarm about ) and filled the ecu with errors.............

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I think I've really lost the plot....

 

Whilst waiting for my new IAC, I thought I'd check my TPS. I plugged in Freescan and the TPS voltage was sitting at 0.47v (from memory), so I tweaked it to 0.51v. I then had a look at the range of the TPS. It went from 0 to 100% (hard against the carpet). With the engine not running, the values seemed to go up relatively normally.

 

With the engine running, on the Sensor Diagnostics tab, I tried to compare the scaled values with engine rpm (car in neutral).

 

At idle (1200rpm), the scaled value was 0%

At 2000 rpm, the scaled value was 1%

At 3000 rpm, the scaled values was 2%

At 4000 rpm, the scaled value was 3%

 

I can't see the sense of having so little variation for the more than half the rev range. The engine did seem to spool up normally in relation to pedal position.

Prior to a run, I checked the battery voltage via Freescan. It was 13 point something with the engine running (It did seem a little low earlier using a meter across the battery terminals (11.8volts)

 

Anyway, I took the car for a run.. and it wasn't long before I got a check engine light and the engine started coughing and spluttering. I pulled to the side of the road and tried to find what caused the CEL via Freescan (which was plugged into the passenger ALDL). There were no errors logged, but I did notice the battery voltage (was 10.7v).

 

Back home, I tried to figure out what was going on. A direct reading on the battery showed 11.8v with the engine off (11.5 with the ignition on and the fans (now) running) with a voltmeter. Unfortunately, like my original problem, I was subsequently unable to run Freescan again. It simply wouldn't talk to the ECM.

 

How low can the battery/alternator voltage go before the ECM stops working? It was still talking to Freescan when the volts were down to 10.7v.  Do the ALDL adaptors also stop functioning if the battery voltage gets too low?

 

At this point in time, I'm not sure if I have an intermittent alternator problem, an new ECU problem or perhaps an ALDL adaptor problem or a combination of all 3.

 

Anyway, I had a look at the brushes on the alternator, they seemed long enough, although there seemed to be a lot more wear on one than the other. The regulator looked physically ok, but I've ordered a new one... My local electrician orded one for A$175... not so cheap these days. Due in a few days.

 

I didn't get any Freescan logs.... too many weird things going on.

 

Is there anything I might be overlooking?

 

Thanks

Cheers

Ian.

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Ian

I'm not sure about the voltage issue to the ecu.

But should the fans have been running??? It's common for a dud ecu to run the car badly, chuck the fans on and give no codes.....whilst kicking freescan into the long grass.

Of course it could be something entirely different - but I would try a swappsy ecu as you can get them for usd80. Don't forget to swap out the memcal

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But should the fans have been running??? It's common for a dud ecu to run the car badly, chuck the fans on and give no codes.....whilst kicking freescan into the long grass.

 

 

That was my original problem. I've only driven the car three or four times since I put in a new one. I think I've only had one good drive, although I can't recall how long it was.

 

Of course it could be something entirely different - but I would try a swappsy ecu as you can get them for usd80. Don't forget to swap out the memcal

 

 

I'm a bit reluctant to throw a new ECU at the car at this point. I think my last one was over U$200 from Rockauto. The ordering system shows a price of US103.79 plus a "core" price of U$90. Total U$193.79 plus postage. That's well over A$300.  I do recall that there was one forum message about an Esprit owner tried two ECU's without luck, but the 3rd was ok.

 

I'll see how the regulator goes. I thought about a new ALDL to series adaptor, but I don't think they are available any more. I haven't been able to get my ALDL to USB cable to work.

 

Cheers

Ian.

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Ian, man sorry to hear about your issues.  I thought I was the only one with CELs at the moment.

 

Tonight, I'm going to go back to my original IAC sensor and see what happens.  Since my MAP sensor didn't work as well as my recent TPS sensor, I'm guessing I have some issues with the cross referenced part numbers.

 

I'm trying to do everything by the manual to avoid adjusting the air throttle stop.  I don't know if this has anything to do with my recent throttle cable replacement as to the throttle stop change.  We had to modified the abutment nut to get the end piece to pass through, but we didn't change anything on the throttle assembly.

 

Bill

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Now that I put the original IAC sensor back on, the car runs a lot better and I was able to drive with Freescan logs that hopefully Travis can translate for me.

 

The TPS is at .53 instead of .49 and I can't get it down any lower.  Freescan states .45 on the TPS sensor.  Would  a Lotus IAC part reduce this setting or do you recommend changed the air throttle stop by an 1/8 increment?  I state the Lotus part since many of the sensors I purchased don't work from the cross referenced parts list.

 

The new spark plugs were gapped at 42/1000,  The Lotus sticker states to use 35/1000 on the plugs, but when I had the service done by Lotus they were gapped at 41/1000.

 

My question is what is the proper gap for the plugs according to the manual as I couldn't find it listed?

 

I still have the Error 41 code so I'm considering switching back to the original coils and DI module just to pass emissions.

 

I'm hoping get the TPS down to .45 and then the ECM will learn these settings. 

 

The car does kick the idle up when on a slope to 1,300 to 1,400 rpms.  I tap the gas hoping to bring it down, but it seems to be sticking.

Edited by bogle

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I would leave that air throttle well alone.

Why can you not adjust the Tps?? You should be able to adjust easily. I would also leave that at 0.53.

Have you reset the iac and blm and done a full relearn? You need to warm up and the go for a drive to do that correctly.

The slope but I do not understand - that's a good one???

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I'm hoping get the TPS down to .45 and then the ECM will learn these settings.

 

 

Where did you get the .45 value from, Bill. According to the Lotus Service manual (EMH2), .50 is a typical value for fully closed, .45 is for fully open.

 

According to the manual, "if a fault is detected and a trouble code set, the ECM will set an artificial default value for the TPS signal to enable a 'limp home' mode. This mode will result in a high idle."

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Barry,

 

We have tried adjusting the TPS to get it lower and .53 was the lowest it would go.  Yes, I have tried multiple IAC resets and blm.  To be honest, I forgot if we did it before swapping back to the original IAC sensor.

 

Ian,

 

Thank you for checking the EMH.  I know we checked it originally at .49 and then swapped for a new IAC (of which the shape was wrong).  We also had the new TPS sensor on and it wouldn't work.  Then swapping back to the original parts the TPS would only go as low as .53.

 

The idling has been around 1,100 rpms.  It's just going up on the slope of my driveway at the end of two test drives I notice the 1,300 to 1,400 rpm shift. 

 

Going to re gap the spark plugs tonight.

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We also had the new TPS sensor on and it wouldn't work.

 

 

Can you tell me where you bought it? I was looking at buying one from SJ Sportscars at some point., but the one shown on their site looks different to mine (from memory).

 

Is there any chance that the accelerator cable is not allowing the throttle to close properly (thus the TPS has run out of adjustment)?

 

It's just going up on the slope of my driveway at the end of two test drives I notice the 1,300 to 1,400 rpm shift.

 

 

Strange indeed.  Are all the electrical plugs secure. Maybe you're losing sensor data at a certain angle.

 

I replaced my plugs recently and gapped them at 1.0mm as per the manual, whatever that is in thou.

 

Cheers

Ian.

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