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Discussion Starter #1
Hi All,

I have just redone my motor making it a 9.8cr and flowed the heads matched to the inlet. Also installed a Rpi TorqueMax cam for it and had a custom set of headers made to suit the low end torque target.

Just done 600 odd km now and the thing is as dead as dirt!

Looking at the various parameters from the Faultmate I see the ignition timing is retarded down to 5deg under acceleration!
I have checked the MAF, TPS, have removed the knock sensors from the block thinking it might be picking up something thinking it is knock, but there is no audible knock from the motor and still it retards the timing.

I am out of options now, anyone have suggestions?

Where can I find info on the Motroninc 5.2.1 showing what the overriding systems could be?

Cheers,
CRV.
 

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Did you make any changes to the orientation of the cam positioning sensor?
 

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Discussion Starter #3
Hi Hoges,

I didn't remove the sensor from the front cover at all as it was very tight and I did not need to remove it.

Can that infuence the ignition advance?

I just tried another MAF meter but same result, down to 6 deg under acceleration.
 

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Under heavy acceleration one would expect the advance to retard somewhat... signficantly advanced ignition timing is primarily to ensure efficient combustion with lean(er) mixtures especially on light throttle cruise and overrun. Of course the higher the rev range the greater the advance as well... 6 deg is low... :think:

did you rebuild the motor yourself? If so, can you remember as to how you lined up cam to ensure it was at the correct position at TDC... am wondering if the chain drive might be slightly out...also have you ensured the cam position sensor wires are properly connected?

I shudder to think of how one might check for corrupt fuel mapping on the Motronic 5.2.1...

best of luck...that's about all I can think of for now...getting strong signals here to pack it in for the night :roll: :oops:

cheers
 

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Discussion Starter #5
Hey Hoges,

Did it myself yes.
Timing marks on both the gears were lined up as per the manual.
The sensor plug is plugged in good yes, made sure of all the plugs.
I'm sure the ECU will send a fault if it does not see the sensor (short circuit or open circuit) but if it just does not see the cam wheel it will not report a fault.

How do I know if the sensor is reading good or not?

My fueling is correct, I have a O2 sensor in the exhaust and it shows between 13 and 15 AFR all the time.

Well, thanks for the suggestion, will try to get a reading from it.

CRV.
 

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Both the cam and crank sensor are the main parts of your timing circuit. The large flat surface on the cam sensor can easily pick up a carbon flake or bit of stray metal throwing the pulse reading off. It's imperative that the magnetic surface be spotless upon reassembly.

Another possiblility would be a flaw in the wiring for either of the knock sensors. I recently worked on a buddies rig and he had cracked the wiring to one of his knock sensors replacing his starter cables. The wires were rubbing and the system threw the timing far enough out of whach that he almsot didn't make it home it was driving so poorly. A couple bits of tape and a reset of his adaptive values and she was good as new. You did reset your adaptive values, right?
 

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What spark plugs you using and I would be testing them HT leads......
Camshaft sensor faulty throws injection timimg out 180 degrees and causes under power but then it should give a fault
 

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One other possibility is that the Motronic system is a bit strict about things, unlike GEMS. It may just not like the setup you've presented it with. Just a thought. :think:
 

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Discussion Starter #9
Thanks for all the suggestions!

The cam sensor was clean on assembly.
I use NGK BCPR6EIX-11 Iridium resistive plug.
I do think the Motroninc is being a bit unfair yes :x

I removed and reseated the knock sensors last night, reset adaptive values and on the work run this morning got 10 deg more advance! :dance:
Not what I want yet but dumping the data to a trand shows the knock defenately retarding the timing. Need to measure howmuch knock is really going on.

How does one do that? What are normal values nad what is high?

See jpeg attached.
Knock in cyan at the bottom and the 8 cyl advance on top.

[attachment=0:3gh7sf2s]Knock.jpg[/attachment:3gh7sf2s]

Cheers,
CRV
 

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Discussion Starter #11
Why would that be?

You recon the cam is not suitable?

It is only 1 deg later on the inlet peak and 6deg later on the exhaust peak. Has less overlap but this only helps at high rpm and less duration but 0.8mm more lift. As my vehicle is modified for overland tourin I very rarely get over 4000rpm.

I already get 4l less fuel consumption on the open road and get 100km more out of a tank in urban use from previous `) (Mine was a low compression motor)
This will pay for all the mods with in 60,000km :wink:

CRV
 

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customrv said:
Why would that be?

You recon the cam is not suitable?

It is only 1 deg later on the inlet peak and 6deg later on the exhaust peak. Has less overlap but this only helps at high rpm and less duration but 0.8mm more lift. As my vehicle is modified for overland tourin I very rarely get over 4000rpm.

I already get 4l less fuel consumption on the open road and get 100km more out of a tank in urban use from previous `) (Mine was a low compression motor)
This will pay for all the mods with in 60,000km :wink:

CRV
If its ground as stated then fine,I just dont trust them to supply EXACTLY what they say it is.I have to admit I've never taken much notice of the live data showing advance,as I'm usually looking for misfires or bad fuel trimming - so I'd want to look at a "known good car" to compare.
I've never bought anything from RPI,only diagnosed cars that they hav e recently "worked on".This is where my caution comes from.Also back in my youth fitting a "fast road cam" to my Dolomite sprint resulted in allsorts of weird running problems - none of which were there with the original fitted.
 

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There's a precaution in the 5.2.1 manual regarding the cam gear, in that the gems gear looks like the thor gear but is different in how the four sensor teeth are arranged. If you're using the original gear then forget the comment, but if the cam was purchased with new gears, perhaps gem gears were supplied? The manual indicates it will default to the safe timing strategy if the cam sensor signal is implausible.

I think you're on the right track by resetting the adaptive values. Motronic stores the knock memory and relies on it to give the best performance for the fuel you're using.

If you have an older version of RAVE, you can find the motronic 5.2.1 manual under Discovery II, technical information.
 

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Discussion Starter #15
allyv8 said:
If its ground as stated then fine,I just dont trust them to supply EXACTLY what they say it is.I have to admit I've never taken much notice of the live data showing advance,as I'm usually looking for misfires or bad fuel trimming - so I'd want to look at a "known good car" to compare.
I've never bought anything from RPI,only diagnosed cars that they hav e recently "worked on".This is where my caution comes from.Also back in my youth fitting a "fast road cam" to my Dolomite sprint resulted in allsorts of weird running problems - none of which were there with the original fitted.
I have had very good service from them. (purchasing parts only) My first cam set to me (South Africa) was snapped in two and they immediately shipped a replacement when I informed them and they help with the claim from the shipping company.

I specifically selected the TorqueMax cam for my application as my vehicle weighs 2.8tons when touring and most of the driving is done on gravel/sand under 80km/h.

I bought a new cam gear but it is an exact replacement, checked it before installing.
I think I have found my problem, having some knock due to the high compression (high for a LRV8)
Will try some additives to see if it will lessen the knock or if the sensors are just a bit oversensitive (my guess).

I have a fairly old version of the RAVE's not sure I have the Motroninc manual!! Where do I look for that in the RAVE's?

Cheers,
CRV
 

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Discussion Starter #16
Ok, I think my Cam sensor is ok. Just found this in the manual......

Symptoms of a CMP sensor failure include the following:
• Ignition timing reverts to default values from ECM memory with loss of cylinder correction.
• Loss of active knock control and diagnostics.
• Loss of cylinder identification for misfire diagnostics.
• Loss of quick synchronisation of crankshaft and camshaft for cranking/start up.

I have individual cylinder timing correction as seen in the jpeg I posted.
I have active knock control (can see the knock control active/inactive indication change)
I have correct misfire identification as I had a complete misfire identified on no7 plug, turned out to be the plug.
I have no starting delays or long cranking.

Will try some octane booster or racing fuel and see if the knock redings go away.

CRV.
 

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I dont think your raise in compression is the problem - its not enough to make much difference,the Bosch system is quite tolerant in how it works.What kit is fitted to your car in terms of emissions - oxy sensors and secondary air etc ?
 

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If you have the electronic version, select Discovery II, then scroll down to Technical Brochures. It lists it as Discovery Series II BOSCH M5.2.1

If you have the printed manual, you'll have to go through the index for Discovery II and find the technical section. I'm not absolutely certain that all of what's in the electronic version has been included in print.
 

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Discussion Starter #19
allyv8 said:
I dont think your raise in compression is the problem - its not enough to make much difference,the Bosch system is quite tolerant in how it works.What kit is fitted to your car in terms of emissions - oxy sensors and secondary air etc ?
I don't have any of that fitted. Only the purge canister.

I have custom headers and exhaust with a Innovate LC1 O2 sensor at the last Y connection before the first box.

Pics here:
http://picasaweb.google.com/customrv/TheP38

CRV.
 

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Discussion Starter #20
Some compression test values after 800km:

Cyl, First stroke, Final reading
No1 1000kPa 1200kPa
No2 1050kPa 1200kPa
No3 1000kPa 1200kPa
No4 900kPa 1200kPa
No5 900kPa 1200kPa
No6 950kPa 1100kPa
No7 1000kPa 1150kPa
No8 1000kPa 1150kPa

Funny enough No6 is always the one with the most retarded ignition value!

CRV
 
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