Zetec Puzzler

[Bob Tucker]

Hi Guys,

you may remember John Hetherington's (johnstillbuilding)

stunning 2B which is ready now for IVA.

But he (& I) are having a nightmare getting the engine to start.

It's from a running Mondeo, fitted with an ECU & twin webers from Dunnell.

the car has been to BD in sittingbourne to have the engine set up 3 times now.

They couldnt get it ro run at all the first time. I went down to help & we fitted new plugs

& got it to start using easystart, but it was very uneven. A few days later it wouldnt start again.

John has fitted.....new coil, new HT leads, new plugs, new crank sensor, and even a new pair of Webers!!!

on advice from BD who said that Dunnell had supplied the wrong type??. On the last visit, to BD the engine ran

OK up to 70 mph, but again it wont start now.

 

From what Ive seen the spark is very weak, barely visible, & its just the same after all these bits have been fitted.

I'm looking to go down & help soon, but I have no idea where to go from here.

 

Any ideas?

Bob

[Bob Tucker]

Ta CMA....

thats a good start for the list!

[steve in stockport]

Check all the free things first, engine earth, ecu earth-has it got it's own good clean earth point, 12v supply to ecu and coil, is the battery in good condition and not run down from all the trying. Wiring continuity on crank sensor plus a comp test as Rob said. Air leaks on the inlet side.

Then start buying things, plugs-zetecs are/were super sensitive to plug fouling and once soaked in fuel never seemed to run right. Can you swap the coil pack for another to eliminate that and maybe even the ecu.

Are the coil and ecu near each other? Possible interference but probably unlikely.

Edited February 25, 2015 by steve in stockport

[Guest 2b cruising]

Hi Bob. Remembering another item that went wron, first thing I would do would be to check all the engine earths.

Didn't he have that problem with the lights or something?

Even worth going down the route of temp earths to each point.

HTH.

[Guest 2b cruising]

I do remember the last fault was faulty earth in his wiring loom. Maybe the same fault now cos that was cure with new earth wire.

[Fossett]

Hi

 

I had this with my zetec, and it was (i'm pretty sure) the coil pack, as mentioned here ^, check the wiring and even try a spare one.

 

I got a new one from motorsport electronics and its transformed the car

 

Cheers

[keith kelly]

Coil packs are cheap as chips from euro car parts think mine cost me £16 not worth faffing with a second hand one at that price.

[Bob Tucker]

Many thanks guys,

a few things there that we havent tried yet.

Keep 'em coming!

[stevedohc2b]

Bob

Is it a dunnell ecu as when i had mine rolling roaded they had a car with one that could not pass I VA so it was going in bin .!!

 

But if it has been on rollers should be set up ok.

 

I could pop over with mine one week end and help

 

Stephen

[Guest alfaGTA]

As above check the spark is strong on all plugs, as Steve said the plugs are sensitive to pollution by fuel but not to the extent that it wont start...

 

Coil packs changed during the production of the zetec engine btw.....

[stevedohc2b]

It the ECU just spark or is it injection thinking if webber must just b spark Un less throttle body.

Stephen

[tractor]

pick up a used eddis pack and try it without the ecu

[Bob Tucker]

Hiya tractor.....im a real luddite with electrics...

but we never had this much trouble with points & condensor. LOL

 

What is the EDIS pack.

 

The spark has been consistently weak all through this.

John has bought a new coilpack, ht leads, plugs, carbs! & the ECU

has been back to dunnell & tested OK.

 

Thank for all the suggestions guys,

after all the work John & his wife have put in, it seems cruel that he cant get it IVA'd

[sj-bradley]

I know the crate Zetec I have came with slightly different shaped points on the plugs.

 

Yet these are the ones specified for the Zetec.

If you say you have changed plugs, HT and coil pack and you say you still have a weak spark, how are you testing this?

 

As this is a wasted spark system, the two plugs that spark together must have a very good connection to each other - body - body through the cylinder head.

 

If you are just resting these on the head, it may not be sufficient. Take the pair you are testing and short them together with a GOOD quality jump lead. They do not need to touch the chassis earth (probably better if they don't).

 

The circuit is formed out of one HT chimney on the coil pack, through the plug, jump lead, plug and back to the other HT column.

 

If you get a good spark with the plugs NOT touching the metal cylinder head and weak when touching the head I think you may have the spark shorting to earth or through the other two plugs back through the coil pack.

 

The coil pack should have resistance readings of 0.5 ohms from centre pin to either side and ~ 1 ohm between the two end pins. The HT columns should show a reading of approx 10 kohms (10,000 ohms) and only connect 1-4 and 2-3. There should be infinite resistance (or very high Meg ohms) between 1-2 and 3-4

 

It just gives and indication that the coil pack looks ok. There may still be high voltage breakdown inside though.

 

Also I believe the HT leads also show approx 10kohms each due to their suppressing content.

 

Look for tracking marks on the plugs, leads and coil pack.

 

Other than that, I would think that the ECU is not switching the coil pack quickly enough, yet you say it has been tested ok

 

Simon.

Edited February 25, 2015 by Simon B

[Bob Tucker]

Hi Steve,

many thanks for your generous offer

I'll see what John wants to do.