Saxo turbo only running on 2 outer cylinders

[robster247]

Okay so I fired up the saxo earlier after finishing my exhaust so ofcourse I had to see what it sounded like . Hooked up the battery, switched on the pump and tried to start it .

Taken a lot of cranking to get it fired up and immediately it sounded awful, felt the manifold and the two inner runners were stone cold while the outside were red hot .

Removed coil pack and tested for spark - all four plugs were okay
Removed fuel rail and checked fuel was being sprayed- seem fine

I don't know how much fuel is in the car as the gauge doesn't work due to the s40 ecu . Could this starve the two inner injectors ?

[AXracing]

Normally a pickup problem with fuel would effect all cylinders. The car sounds very none standard but if your using a wasted spark ignition then its very likely to be an issue with the spark. If it sounds terrible the spark timing may just be way out. If really nothing is happening on the outer two then you may not have enough amps to fire the outer two. Do you have another coil you could try? Does the s40 have a built in driver or is a separate unit ( never used the ECU).

[robster247]

Normally a pickup problem with fuel would effect all cylinders. The car sounds very none standard but if your using a wasted spark ignition then its very likely to be an issue with the spark. If it sounds terrible the spark timing may just be way out. If really nothing is happening on the outer two then you may not have enough amps to fire the outer two. Do you have another coil you could try? Does the s40 have a built in driver or is a separate unit ( never used the ECU).

Had a play around with the car today, checked over all the wiring and earths ect. Found no problems with that, swapped for another coil pack and tested.

Car ran but only one cylinder now . 3 cold runners and one hot . So I swapped the plugs around and it changed cylinder.

So I've had 3 dead plugs for some reason, popped down to halfrauds and got a new set , put them in and tuned the key and it sounds like a race car again hahah.

I have no idea if it runs wasted spark , sandy brown made me the loom and supplied the s40 with a base map. Runs very rich but only wanted it ticking over to check for leaks ect before mapping

[welshpug]

they'll be fouled plugs, and you really don't want to go to halfords for plugs very often, they are particularly expensive and dont have a great range.

a local motorfactor or online retailer is best place for plugs.

yes yours will have a wasted spark arrangement likely with batch fire on the injectors.

[Chipwizards]

People very rarely set up startup fueling correctly on DTA ECUs. They are a good ECU but the startup maps they come with all have dreadfully rich crank and post start fueling. Trouble is, too many mappers don't change it to sensible numbers so plug fouling becomes too common, further helped by probably colder range plugs and lower compression in your case too.

[robster247]

I thought they would be fouled plugs , have enough experience from the motocross days, especially the old 2 strokes haha .

Yeah got a set of bcr8es which are the cooler running plugs . I was bricking it as I've been trimming back the loom behind the dash and thought I'd gone into something I shouldn't have.

Nice easy fix thankfully

[welshpug]

People very rarely set up startup fueling correctly on DTA ECUs. They are a good ECU but the startup maps they come with all have dreadfully rich crank and post start fueling.

I've just discovered that myself, though I have no idea what values to try really, I just need the sod to start easier without fouling the plugs so I can get it to an MOT, or at least onto a trailer!

Any idea what kind of values I should try?

[axsaxoman]

what is it set at at this time ?
--eg %fuel increasefor number of turns at cranking
eg +80%for first 16turns then + reducing very quickly as more starting turns --then its water+air temp correction up to 30-40c water temp
and are you sure water temp sensor is calibrated right for bottom of scale --that is another common thing people don,t do ,just assume that its linear -- check sensor is actually correct at low temps--those are really the main things for cold start
esay to do just a bit time consuming----use very salty water and you can get into minus temp readings on sensor -high ones easy with a kettle and just let it cool while checking sensor.
warm up map takes more time to do than mapping for power if you want it to run like a production car --and every engine type is different for what it wants for good cold start+warm up .
main problem is you only get one proper cold start per day --so you have to be quick in logging or altering things
I used to pride myself that the ax race car i could just turn the key and walk away from it while it warmed up -no extra throttle after first 5 seconds + no extra air device either ,but that also means adjusting ignition timing as well to get it spot on --plenty of scope in the dta for making a perfect warm up map -- but customers never want to pay for time to get that right + why tuners gaurd their warm up maps for particular engines.
turbo,s easy just use the idle valve for extra air like std ecu--t/bodies is harder

much easier if you have a w/b fitted cos you can see whats going on as it warms up and correct it

all the above is why wayne likes to use std ecu where possible --cos it is easy for him to alter all these things using std idle valve + cold start will be pretty close to start with

you may find good cranking map on DTA forum

[welshpug]

its over the 100% mark!

sensor is standard and uses the dta provided values for that part number, readings look accurate, i.e from a stone cold start air and water are at the same temp, coolant rises same rate as the standalone o.e temp gauge.

[welshpug]

I do have a wideband, will post the values later, going for an MOT today as it happens so hopefully I can get it started, got a 5 mile run there.

[axsaxoman]

I do have a wideband, will post the values later, going for an MOT today as it happens so hopefully I can get it started, got a 5 mile run there.

its something you can play when your bored, as cold start map has no effect once its up to temp--usual rules always save present map before altering it in case you make a mistake

[Chipwizards]

The biggest issue with startup map is that it's duration is far too long.
I set the number of turns header to 2,4,6,8 etc up to 20 (for a quick decay) then 25, 30, 35, 40 up to about 60 and then big jumps for the last few bytes because some engines, particularly when the injectors are a long way from the valves, need a while to fully wet the walls.
Then look at the extra fuel table, but in graph mode then 'flip' it so you're looking at it from an angle that you can see it properly (cranking turns now going from the corner opposite your viewpoint down to the right and temperature increase down to the left). It should be up in the opposite corner and decay pretty exponentially to the right (in respect of turns) and more linearly to the left with respect to temperature. Cold I'd start with 100% extra decaying to maybe 20% after about 6 or 8 turns. Hot maybe add 10% for a few turns then have it at zero the rest of the way. Blend nicely between the two. They work mint when you get them set right, turn key, no throttle step away and it's idling like it should, although a bit slow through being cold of course.