P38 v8 4.6 Edis - Using Crank Sensor Instead of VR

[zim]

Evening,

I pulled out my p38's 4.6 today to go in my challenge buggy, which is currently a 4.2 non serp.

My 4.2 is currently running MS with edis.

I got the brackets and trigger wheel from Nige to fit to the front of my gems 4.6 serp.

BUT, when i got the engine out i was looking at the crank sensor ? I haven't checked where the gap is in relation to TDC, but a look on google shows that they have 35 teeth and a missing 1. Same as an edis trigger wheel.

Has anyone run MS with edis using the standard crank sensor ?

It would make my life easier as i run a crank driven hydraulic pump and having a 'loose' trigger wheel makes mounting things awkward.

I had a quick search and found this thread :

http://forums.lr4x4.com/index.php?showtopic=73515

Here's my missing tooth, excuse the oil leak from the sump :

From google :

G

[TheRecklessEngineer]

It might be the same as EDIS, but I don't think it is correct in relation to TDC.

MS might be persuaded to use it, but I think EDIS will struggle.

[zim]

I know this isn't megasquirt, but there seem to be a lot of similar aspects to it :

http://www.lloydspecialistdevelopments.co.uk/assets/files/Downloads/Rover%20V8%20DIS%20Kit%20Instructions%201.6%20Canems%20GEMS.pdf

Page 12 :

Rotate the engine until No.1 cylinder is at TDC as indicated by OEM timing marks. Check No.1cylinder is at TDC very carefully with

a long probe or screwdriver. Please do check the accuracy of damper rim TDC markings (we have seen them as far as 10 degrees out!)

2.

Count the number of trigger wheel teeth between the Crank VR sensor to the missing tooth, in the direction of crankshaft rotation. In this example the

missing tooth is 6 teeth or 60 degrees after the Crank VR sensor. This means the missing tooth passes the crank sensor 60 degrees before

cylinder 1 is at TDC

Should work then as we have 45 degrees to play with on MS ?

Oh, or :

http://forums.lr4x4.com/index.php?showtopic=53572

The output signal from the CKP sensor is obtained
from the magnetic path being made and broken as the
reluctor ring teeth pass the sensor tip. The reluctor
ring has 35 teeth and one missing tooth spaced at
10°intervals. The missing tooth is positioned at
20°after TDC.

Erm..... ? I'll have to check.

[Bowie69]

Interesting, what year is the lump? I was fairly certain on my 1995 P38 4.0 is was a 36-2 tooth wheel, but as your images point out, yours is definitely a 36-1 wheel.

On the Lexus 4.0 I squirted, I just removed the original sensor (though it quite possibly would have worked with EDIS anyways) and bolted in place the standard one that Nige supplies, albeit with a washer or two to space it from the ring a bit. You could do similar, or even drill a snug hole where you need the sensor in the engine backplate/TC cover plate or even gearbox bell housing if it's not in the right place?

[zim]

Mine is a 1994 / 1995.

If the 4 bolt holes are equally spaced and concentric, then i could possibly rotate it 90°, with a little bit of adapting.This will now put the gap -20 + 90 = 70° BTDC. So i could trim it 10° in the settings.

G

This is the sensor :

[TheRecklessEngineer]

If it's possible that you can rotate it as you suggest, then EDIS will probably play.

If not, then MS with direct coil drivers should play - although I've never done this, so can't really advise further!

[Bowie69]

OK, rethinking a bit, and knowing you are not shy with a welder, there's nothing to stop you cutting off one of the teeth in the right position and re-welding it where the current gap is.

Then pinch the two prongs on each together, and make a bracket to hold the normal MS VR sensor in place of the old one.

I suspect you want to get this right from the off, otherwise it is engine out time, do you have an engine stand to run the engine up on on MS? Could test the P38 sensor to see if it is going to play nicely with EDIS or not.

I'd strongly suggest not going down direct coil drivers if you can help it....

[Bowie69]

Ah just realised, Thor is a 60-2 wheel, hence my confusion.

[zim]

Torque convertor removed:

Flex plate removed. Notice dowel / locator pin at nearly 12 o'clock:

With the engine at TDC, the missing tooth is 2 teeth behind the crank shaft sensor.

Rotate the fly wheel round 90° and redrill the locator hole. Notice the marker pen lines from before.

A bit difficult to see, but the missing tooth is now 7 teeth ahead of the crank sensor when at TDC. I can make adjustment with megatune i think.

The engine will go in later this week. Hope it works.

G

[elbekko]

Could you drill out those rivets and re-rivet the trigger wheel in the right spot?

[zim]

Could you drill out those rivets and re-rivet the trigger wheel in the right spot?

Yes. But you can only turn it in 90 degree increments, which is the same as what i've done. I didn't want to re-rivet it back on as i don't trust (aftermarket) rivets for a ring that's spinning at 4,000 rpm next to a sensor.

G

[Hybrid_From_Hell]

Zim

Checked for you re call,

you can trim in Spark settings - or + 45 degrees so yes your OK with 2 teeth out

Nige

[FridgeFreezer]

This is the sensor :

I'm confused as to why you'd change the sensor - it's 2-pin so presumably must be a VR type, as long as you get the polarity correct EDIS should work with it, no faffing required.

[zim]

I'm confused as to why you'd change the sensor - it's 2-pin so presumably must be a VR type, as long as you get the polarity correct EDIS should work with it, no faffing required.

I'm not going to change the sensor. That's the type thats on my engine. If you look at my first pic in post #9 you can see the blue plug.

G

[Bowie69]

I'm confused as to why you'd change the sensor - it's 2-pin so presumably must be a VR type, as long as you get the polarity correct EDIS should work with it, no faffing required.

I only suggested it if it didn't play with EDIS, fingers crossed it will

[elbekko]

Yes. But you can only turn it in 90 degree increments, which is the same as what i've done. I didn't want to re-rivet it back on as i don't trust (aftermarket) rivets for a ring that's spinning at 4,000 rpm next to a sensor.

G

If you use proper quality rivets, I don't see why it wouldn't work. And if you redrill the ring, you could even get it spot-on. Of course, redrilling would take a lot of careful measuring, but it should be possible.

[Escape]

I'd strongly suggest not going down direct coil drivers if you can help it....

A bit off topic, but why would you avoid direct coil drivers? I have a MS kit lying around (since last year) that should end up in my 4.6 P38a ('96) and I would also want to try and reuse the standard CKPsensor. Preferably without having to take the engine or gearbox out again...

[Hybrid_From_Hell]

Coil apck driver are (IMHO) very finicky and can be a giant pain to get sorted

Istruggletogate11 spent an age having issues andswitched to EDIS and never looked back

EDIS is a replacement for DCDs, many people I think steer away from EDIS as they (EDIS *s) are tricky to

get as never in this country, so DCD are an "easier" route for them (sod the customer sort of thing)

Luckily I have supplies of these and I still think EDIS is a robust options vs DCDs

I am sure there will be others along who can add to the above with far more knowledge on them than me

but I now try to avaiod working on DCD powerd MS esp when the owner says "I have a problem" .....

Nige

[FridgeFreezer]

DCD is electrically difficult to fit into the MS, as you're putting 4x driver transistors in the main ECU, with high currents into coils with large voltage spikes / EMF coming back and trying to escape through the ECU's ground connection. Most people who do DCD end up cutting a 2nd D connector into the back panel & running separate power/ground/coil connections through that and isolating it from the rest of the ECU to prevent software resets & interference.

I'm not saying it's not doable, or that it's bad (DCD does open up more options like different trigger wheel setups, spark-cut rev limiting, etc.) but for most people EDIS is a plug-and-play idiot-proof system - if you get the wires in the right order, it will run, and the connection to the ECU is just two small signal wires with no nasty spikes.

Modern cars often have the coil drive incorporated into the coil/pack itself for these reasons, and that's certainly the option I'd consider if I was going away from EDIS, but for now it's a good system and it works, and there's enough millions of EDIS modules out there that we're not going to run out any time soon.

[Escape]

Hmm, I understand the difficulties, but I'd still prefer to spent some more work on the DCD and not have to fit a trigger wheel. So I'll certainly be keeping an eye on this thread.

Filip

[zim]

If you use proper quality rivets, I don't see why it wouldn't work. And if you redrill the ring, you could even get it spot-on. Of course, redrilling would take a lot of careful measuring, but it should be possible.

You couldn't get it spot on. You can only rotate it 90°. If you look at my first picture in post #9 you will see where the torque convertor bolts onto the flex plate. These 4 bolts are accessed through the ring - which has 4 big holes.

It's a lot more work to re-rivet the thing than just move the whole lot. But yes, it's possible.

I have been making a new hydrualic pump drive so not done any more on this side of things. Going to remove my 4.2 this weekend.

G

[Bowie69]

Hmm, I understand the difficulties, but I'd still prefer to spent some more work on the DCD and not have to fit a trigger wheel. So I'll certainly be keeping an eye on this thread.

Filip

Once you have the machining done for a serp MSing, the rest is bolt on and very easy.

[FridgeFreezer]

EDIS or DCD are about as hard as each other (which is "not that hard"), they just have different obstacles to faff with. EDIS needs the trigger wheel, DCD needs more electronics.

I think DCD with ignitor coils (where the driver is in the coil) is a very nice solution, and it's what I'd recommend to those like Filip who want to do DCD. However, the benefits/drawbacks are so minimal between that & EDIS that it's not enough to make me want to swap.

[elbekko]

Why would you need high voltage and spikes near MS? Using the GEMS coil packs, as Filip would like to do, seems fairly straightforward:

Ignition Coils (Z261)
The ignition system on the petrol engine consists of
a “DIS” format, a Direct Ignition System, comprising
of four double ended coils operating on the “wasted
spark” technique. The circuit to each coil is
completed via switching within the ECM (Z132),
allowing the coil to charge up and then fire. It
produces sparks in two cylinders simultaneously, one
cylinder on the compression stroke and one on the
exhaust stroke. Due to relatively easy ionisation of
the fuel/air mixture in the cylinder under
compression, the coil will dissipate more energy in
that cylinder than the other, so very little energy is
wasted in the system.
Failure of a coil will result in lack of sparks in two
cylinders (coil 1 feeds cylinders 1/6, coil 2 feeds
cylinders 5/8, coil 3 feeds cylinders 4/7 and coil 4
feeds cylinders 2/3). This results in a misfire.
This relay is ignition key controlled and supplies a
feed to the coils, evaporative emission canister
purge valve and heated oxygen sensor. When the
ignition key is turned off, supply to the coils is cut
immediately.

Not sure how grounding a few wires is different from a PIP/SAW apart from it being less prone to interference?

Not sure if MS supports this system out of the box though.

[Bowie69]

It's the flyback from the coils, back down the low voltage wires that needs addressing, if you address it at the coils it's no problem, if in the MS box, potentially a problem.