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SC Zetec can't get an idle
ChrisL - 27/5/19 at 11:02 AM

I'm in the process of trying to supercharge my Zetec Tiger and am trying to get it running. The current stumbling block is to get an idle. It'll start but then stop again. I got a post up on the MS Extra forums in case its an issue with the Microsquirt I'm using, and by issue I'm mean the bloke that's ham fistedly configured it - me!

To try and rule the ECU out I've disconnected the SAW input to the EDIS, so it should default to limp home mode. Using the standard VR sensor in the standard as Ford intended location. I used this combination with a Megajolt when I was on carbs so have no reason to suspect it and I defiantly have a spark.

So my thinking now is fuel pressure if the HP pump is knackered could it cause this?
Or could it be an issue with the SC? The fan belts not screaming and I can hear it, which could be a good thing as in it's turning or a bad in that the bearings may be knackered!!

The plugs are dry and sooty so I'm assuming too rich but burning...

I've also tweaked the throttle (yes just one) idle valve to get the best start

So any common sense things I can check?


mikemph - 27/5/19 at 02:36 PM

Sounds more like ASE curve needs looking at if it will start then die.

You have priming pulse which is like squirting in a bit extra to get it to start. The ASE is enrichment as the engine is getting to running temp. If it still doing it at normal running temps then it the main fuel table you need to look at.

For fault finding block off idle valve and just wind the throttle stop to a good idle speed. When you have the tune nice then start fiddling with idle control valve.


ChrisL - 27/5/19 at 03:17 PM

Ahh, the throttle stop is the idle control!
I thought I'd check the the fuel pressure and fitted a gauge, all was going well until I noticed it reading zero. I quick check to see if fuel was flowing or not and nothing, squeezing the LP circuit caused some to come out so the LP pump is working fine. New HP pump on order. So the Ham pump may have been a factor will find out when the new one gets here.

Agree that the ASE should be the setting to adjust, I had it up to 60% but still no joy but that may have been the pump!!


ChrisL - 1/6/19 at 04:48 PM

Still no further through this. I've tried max and min ASE still won't go beyond a cranking
Anyone got a micro or megasquit map on a similar setup that I can have a look at to see what's different?

2ltr blacktop zetec
bosch 440cc injectors
M62 of a CLK 230 supercharger


ChrisL - 2/6/19 at 01:46 PM

Some progress, I had the MAP sensor wired the wrong way, damn ABC! I suspect this has broken it as wired correctly it's showing 5v without the engine on, so I'm going to get a replacement. While I am, should I go for a 2 or 3 BAR sensor, I'm aiming for 11-12 PSI of boost?


mikemph - 2/6/19 at 02:10 PM

2bar would do it just.


ChrisL - 5/6/19 at 07:33 PM

I decided to go for a 3 BAR just in case! And with a new MAP sensor we have an idle, lumpy as hell but it is an idle. And before anyone says it, the MAP was reading 100kPa but that's all it was reading!!

I've wired the injectors as 1&2 and 2&4 which is obviously wrong, but is it worth fixing?


ChrisL - 26/6/19 at 07:09 AM

I've rewired the injectors and have a running tune, it's far from perfect but getting there.
Cheers for the advice and I'll be back when I put the supercharger back on....