Author Topic: Engine Now runs, see pg 2  (Read 20826 times)

Offline rob@vems.co.uk

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Re: Engine fires but wont catch/idle
« Reply #15 on: April 07, 2008, 06:30:56 pm »
Big trigger problems there - I am suprised we're not seeing the Trigger Errors panel flashing on MegaTune.



Offline Stuball

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Re: Engine fires but wont catch/idle
« Reply #16 on: April 07, 2008, 07:13:18 pm »
When i managed to get the revs up last firday, albeit temporarily, the rpm smoothed out, is it not just the really rough running causing the errors?

will get the stepper motor working before i try again now.

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Offline rob@vems.co.uk

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Re: Engine fires but wont catch/idle
« Reply #17 on: April 07, 2008, 07:23:01 pm »
Stepper motor wont cure that problem, invest your efforts investigating the trigger issues.

Offline Stuball

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Re: Engine fires but wont catch/idle
« Reply #18 on: April 09, 2008, 08:22:49 pm »
Just a quick check here.

As i Have the standard Distributor/Coil setup, what pin should the wire from the negative side of the coil go to?

Stuball

Offline rob@vems.co.uk

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Re: Engine fires but wont catch/idle
« Reply #19 on: April 09, 2008, 09:42:41 pm »
EC36-pin27 is the primary trigger

Offline dnb

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Re: Engine fires but wont catch/idle
« Reply #20 on: April 11, 2008, 12:38:10 am »
There's a text file hidden away in the firmware folder in the Megatune distribution.  This gives all the combinations of stepper values (in hex) to try.

I agree with Rob that cold cranking is a bit lean.  Also check that when the afterstart period ends (usually a couple of seconds), the VE table is sensible.

Offline Stuball

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Re: Engine fires but wont catch/idle
« Reply #21 on: April 16, 2008, 05:43:42 pm »
OK small update here.

rob is looking at my ecu at the moment as it wasnt triggering the fuel pump on any of the p259 channels.

in the mean time I got hold of a stock rover injection system and fitted it as i needed the car running.

Had exactly the same problem,  the car would run for a few seconds then stop,  or not run at all, and kept flooding.

however, today I solved the problem, it turns out I had the wrong spark plugs (too short), fitted which is why she wouldnt fire.  Put some new ones in and it runs really well on the stock system.

fingers crossed when i get my VEMs back and plug it all in it will also work.

Watch this space.

Stuball

Offline Stuball

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Re: Engine Now runs, see pg 2
« Reply #22 on: May 08, 2008, 03:45:10 pm »
Got a replacement ECU from Rob yesterday (cheers for that!)

Plugged it all in and she fired up straight away.

Now i just need to know where to start,  cold idle is a tad fast @ 1800rpm and when hot the idle goes up and down in regular intervals.

FYI Rob this is with the stepper motor plugged in  :)

Here is the datalog and current Msq file:

http://www.box.net/shared/ogjl4pmw40  Datalog
http://www.box.net/shared/rs7osms8c8  MSQ

Second datalog of a quick drive round the block:
http://www.box.net/shared/bawpu5gysk

Just to add, did a quick test and the hot idle is quite steady (albeit a bit high at the moment), until the lambda starts reading.  The EGO correction seems to be making the idle go up and down
« Last Edit: May 08, 2008, 05:32:23 pm by Stuball »

Offline Tony C

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Re: Engine Now runs, see pg 2
« Reply #23 on: May 08, 2008, 05:36:26 pm »
glad to see it was not a wiring issue mate ;-)

Vems Ecu, Twin Plenum efi and N2o
13.314 @ 104.39 mph (10/06/07 3.9 v8)
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Vems Firmware: V1.1.74

Offline rob@vems.co.uk

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Re: Engine Now runs, see pg 2
« Reply #24 on: May 08, 2008, 06:32:07 pm »
Nope, it was a very rare LBUS failure, I couldnt figure out what was wrong after replacing the components again and then I wondered why the wires for the analog in were hot... Measured 5v that didnt seem to be an issue - put the scope on it and it was strobing like a mad thing.

So Stuart got a replacement under waranty.

You have to remember that from my obscured viewpoint the general rules are:
no fuel pump = blown p259 = bad grounding.
No stepper = blown stepper chip = 12v fed to stepper chip (often by shorted stepper wiring).

I'd never heard of an LBUS failure 'till I told VEMS about the measurements!

Offline Tony C

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Re: Engine Now runs, see pg 2
« Reply #25 on: May 08, 2008, 07:53:46 pm »
i was starting to get worried as i made the loom for him :D
when every one kept on about bad grounding etc,

Stu.
have played with your ve table mate, tell me when your ready i'll send the .msq back, run her up and do me a datalog again plz mate.

Vems Ecu, Twin Plenum efi and N2o
13.314 @ 104.39 mph (10/06/07 3.9 v8)
Sponsored by: www.caprisport.com & www.interpart.biz
Web site: http://www.capriracing.co.uk

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Offline Tony C

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Re: Engine Now runs, see pg 2
« Reply #26 on: May 08, 2008, 10:33:33 pm »
Rob.
one thing which has got me confussed,
mine and stus.s are wired the same, but why do we have different injector outputs??

Vems Ecu, Twin Plenum efi and N2o
13.314 @ 104.39 mph (10/06/07 3.9 v8)
Sponsored by: www.caprisport.com & www.interpart.biz
Web site: http://www.capriracing.co.uk

Vems Firmware: V1.1.74

Offline Stuball

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Re: Engine Now runs, see pg 2
« Reply #27 on: May 09, 2008, 12:26:21 am »
What should the MAP be reading at cruise?

Mines sitting at 30kpa.  But my VE Table starts at 30.

Should my table start lower than this?

Offline dnb

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Re: Engine Now runs, see pg 2
« Reply #28 on: May 09, 2008, 12:41:41 am »
MAP at cruise depends on the cam and a whole load of other smaller factors.  (I presume your cam is pretty tame ;)  My MAP on cruise is 45kPa )

30kPa is OK but a little low - best double check the sensor calibration since this is a new unit.  I'd consider rescaling the table to start at 10 or 20 if the calibration is currently correct.

Injector outputs are probably not all that different since they are both batch fire in groups of 4.  There are 2 ways of doing this - as left and right hand banks, or having every second cylinder (in firing order) in each batch.  It doesn't matter much which way is used, but I have a slight preference for the latter.


Offline dnb

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Re: Engine Now runs, see pg 2
« Reply #29 on: May 09, 2008, 01:05:30 am »
Here's what I think the next VE map should be.  It's not too bad as it is, but it does run quite rich in places and lean in others.

Code: [Select]

600 900 1200 1700 2200 2700 3200 3700 4200 4900 5800 6800
30 26 25 20 21 20 22 28 34 40 47 56 60
40 25 25 21 25 26 27 35 39 46 55 63 66
45 23 24 27 26 32 30 39 43 50 58 66 69
55 25 27 31 36 42 38 50 56 61 68 72 73
60 27 31 35 40 45 53 50 55 70 75 77 76
65 30 35 43 46 54 62 59 64 80 83 82 81
70 35 41 47 56 62 62 68 69 89 91 88 84
75 46 52 58 67 67 75 74 76 98 98 94 88
80 57 63 67 75 76 83 83 82 106 106 102 93
85 64 71 76 84 90 94 87 89 114 115 108 99
94 72 80 86 94 99 106 108 121 125 126 118 108
104 77 86 91 100 83 89 127 133 136 136 130 118

I hope it formats OK - row and column headings are MAP and RPM bins from the msq.