35 replies to this topic

[Mat Jackson]

Those on the Itb room with have followed this for a while, but I’m still struggling so looking for input.

Car used to run as stage 1 on alpha with no issues. This year it’s been upgraded to stage 2, with new head and cams and also upgraded to delta SCS ecu with 36-1 trigger wheel. Since then, the car generally won’t start, but will do occasionally... However, if I switch back to alpha ecu and trigger wheel it will.

As it’s intermittent, I thought it was an issue in the loom, particularly the link loom from the original alpha loom to the new SCS ecu.

So, built a new engine loom from scratch for the SCS and installed it last week. Engine started first time, although didn’t sound like it was firing on all the cylinders all the time. Since then, it won’t start....

I’ve tested all the wiring, and found no issues... I’m getting fuel, but think there is a weak spark. In the past (on the SCS ecu) I’ve had issues with it only firing on cylinders 1 and 3, and at other times just on 2 & 4. With the plugs on the rocker cover I can’t get a spark unless they are earthed by wire to the main block.
Also tested the timing and that’s spot on, and ecu is showing it recognises the crank sensor ok and is running at 200 rpm at cranking...

Checked tonight, and I’m getting a good 12v plus to the coil pack too, which makes me think an issue with the coil pack itself giving a poor or no spark.

But - why would it run on alpha? Could a breaking down coil work worse on one ecu than the other? The new SCS ecu has been tested on another car and ran fine... If the switched earth for the coil on 1 ecu was different than the other would that be enough to affect a poorly coil pack...

Answers on a postcard...


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[The Batman]

Answers on a postcard...


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should have fitted a supercharger

[Mat Jackson]

Answers on a postcard...



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should have fitted a supercharger

.

When I saw you had quoted me I knew that’s what you would have said!!! May be a plan b for me...


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[The Batman]

[Mat Jackson]

Thinking about this overnight, I’m the only SCS set up running a 36-1 trigger wheel. So I’ve narrowed it down to one of 3 things...
Coil pack faulty...
Crank sensor not able to work well enough to on 36-1
ECU struggling to read 36-1


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[siztenboots]

try putting a better earth direct from engine block to ecu , jump leads will do for a test

[Mat Jackson]

try putting a better earth direct from engine block to ecu , jump leads will do for a test

Will try that!! Have tested continuity from the ecu to earth and it is good - but will try this too..

Through the ecu I think I can fire individual spark plugs, so will use that to check continuity from coil connector to ground..




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[Mat Jackson]

Also ordered new coil pack from autovaux - they have a returns policy if it’s not needed...


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[fiveoclock]

Also ordered new coil pack from autovaux - they have a returns policy if it’s not needed...


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On electrical items? Are you sure?

[Mat Jackson]

Also ordered new coil pack from autovaux - they have a returns policy if it’s not needed...



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On electrical items? Are you sure?

Yes - if not opened...


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[2-20]

Distance from cranck sensor to target wheel ??
On another car i had to set it beyond the required distance otherwise it did not work properly...

Edited by 2-20, 16 November 2019 - 05:35 PM.

[The Batman]

it will be to do with the crank sensor

 

you have the info in the ecu for a 36-1 yeah?

[Mat Jackson]

it will be to do with the crank sensor

you have the info in the ecu for a 36-1 yeah?

Ecu is set up for 36-1 trigger wheel, and software is showing it syncing too... But still concerned it might be an issue. I’m the only SCS car on 36-1, another is set up with the alpha wheel so might fit that back on and try their map...

But - not sure why it would be intermittent issue though...


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[quimbles]

Only the offset you can change. Is it round he right way? Can't remember if there's more than one 36-1 wheel in the menu.

Also the itbs are really sensitive on the scs setup way more than the alpha. I've had misfiring few times

[Mat Jackson]

Only the offset you can change. Is it round he right way? Can't remember if there's more than one 36-1 wheel in the menu.

Also the itbs are really sensitive on the scs setup way more than the alpha. I've had misfiring few times

Yeah - checked the wheel with a timing gun and it showed as being spot on. However, did struggle to get a spark when testing the timing which leads me to the coil pack...


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[quimbles]

it was my car running the 36-1 on the webcon alpha ecu and sensor.   it did start, albeit with a lot of cranking.  i think that was down to the ecu not being able to process that many teeth in the trigger wheel.

 

so the sensor should be fine. 

[quimbles]

also id check with scs what the spec of the 36-1 trigger is in the ecu.... if its set to run standard ford setting sit could already be say 90 degrees BTDC without touching the offset. 

[Mat Jackson]

also id check with scs what the spec of the 36-1 trigger is in the ecu.... if its set to run standard ford setting sit could already be say 90 degrees BTDC without touching the offset.

Yep - missing tooth is at 90 deg btdc, and timing gun shows it’s in the right place.... Offset in the software is set at zero too...

New coil pack will be here this week, so will try that... After that I’ll try fitting to old alpha trigger wheel as that has now also been mapped in the SCS software....


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[quimbles]

Ah great that's good to know

There's also a trigger sync test in the software, have you checked that?

[NickB787]

What material is the 36-1 made from? Just a thought.