Zetec Puzzler

[steve in stockport]

Bob there won't be an edis on that set up, it was part of the ignition system on some fords in the 90s that will run an engine in limp mode if the ecu packs up.

What power is the ecu receiving, is it getting a good supply? Possible voltage drop between battery ignition switch start relay and the ecu?

[Bob Tucker]

Thanks Simon & Steve,

We were checking the spark by earthing just one plug to the head,

but all the other plugs were still installed.

But again thanks for the ideas.....Ive got a good list to take with me.

I plan to make up a test harness to check the coil pack off the car,

so we can eliminate (or hopefully identify!) any issues in the cars wiring.

[Al Milton]

Hi Bob,

 

If you want I can pop up (but not until the week end unfortunately), with my coil pack just to see whether the new one John purchased is working correctly. I don't know if it would fit, it's from a 2ltr blacktop.

 

I'll pm you my mobile number as that will probably be easiest to contact me on.

This would be a crying shame for John's beautiful car.

 

Cheers

Al

[tractor]

hi bob I know the edis is not part of that ecu set up but the edis is cheap as chips it was just a suggestion to rule out an ecu or wiring probs and is very easy to wire up just the edis only a couple of wires

Edited February 25, 2015 by tractor

[Fossett]

Edis is fords coil driver

 

In a standard car it takes a pulse from the crank sensor

 

It passes the pulse to the ECU - called pip

 

Receives an adjusted (by the map) signal back from the ECU - called saw

 

Then signals the coil to fire

 

The EDIS has a limp-home function whereby if it's used without an ECU or the ECU fails it defaults to 10degrees of advance.

 

Many people get there cars up and running 1st time on EDIS alone to be sure that it runs

 

Hope this makes sense

[Bob Tucker]

Ta Fossett

That makes sense now.

I'm starting to doubt the Dunnell ECU now, even though they say its OK,

so I'll look for an EDIS unit for John.

 

Tractor....thanks for the diagram, I'll print it off & try to understand it!

Cheers guys!

[tractor]

I think if you are running carbs on a zetec although you need a edis the megajolt is the best price and getting maps and set up are very easy

[Guest lotusPaul]

Hi all.

 

Just to throw an idea out based on my experience. I run an emerald/jenvey system on my lotus twincam. The ecu and many others are VERY sensitive to battery voltage. If the charge is not good enough it simply wont start.

 

I run an ecu earth direct to the battery as recommended by emeralds wwiring diagram. I also run a large earth cable between bellhousing bolts and battery as its a glass fibre car.

 

With the large cable disconnected no matter what state of charge the batts in, it wont start without easy start.

 

Check your charge.check your earth's

[Bob Tucker]

Will do.

I have a 110 amp battery & commercial jump leads I will be taking to John's

Thanks for all ideas...

[johnhetherington]

Bob called round this morning to see if we could identify and rectify the fault.

After many hours of head scratching and pondering no conclusion but the observations are;

Turn on ignition, electric pump starts and runs for 5 seconds, correct.

Crank the engine good spark and electric pump running.

Turn off ignition and on again, electric pump runs but does not cut out.

Crank the engine and NO spark.

it does this everytime unless you wait 3 minutes and again it sparks on first crank but not second.

have fitted new coil, HT Leads, crankshaft sensor and plugs.

Good earth to battery and engine.

Booster pack to the battery tried.

The ECU has been sent back to Paul Dunnell to be checked and he confirms it is functioning correctly.

Also checked the voltage at the coil connector and 12v on first crank and also second crank but no spark on second crank

Got me and Bob stumped

Bob do you want to add anything.

Thanks to Bob and all for their help and suggestions

John

[Al Milton]

John,

Have just done a quick google and found this, a similar problem to yours:

 

http://www.xrtwo.com/forum/viewtopic.php?f=3&t=33505&start=0

 

It looks like his problem was a dirty earth on the coil pack.

Hope it helps

 

Al

[johnhetherington]

Hi Al thanks for taking the trouble to investigate, but unfortunately i had already run a separate earth to the coil pack just in case and it didn't make any difference.

Keep the ideas coming

[Al Milton]

Just another thought John, do you have a Throttle Position Sensor (TPS)?

 

Or, not wanting to state the obvious, have you checked the loom connectors to the ECU? Could be a dodgy connector to the coil pack.

[Guest lotusPaul]

Could it be something like a wire thats damaged?

 

IE it works untill it gets to hot then fails.hence having to wait for the heat to cool off before it will work again

 

get a multi meter and check for resistance in your loom

 

To be honest im not a sparky so my knowledge is bassed on check check again and triple check all conections

[Longboarder]

Random thoughts.

Turn off ignition and on again, electric pump runs but does not cut out.........no spark.

That's odd that the pump doesn't stop. Computer needs to see CPS registering movement to overide the five seconds switch-off and keep the pump going. Fail position if CPS is wrong is pump doesn't run.

Noisy wiring to ecu could be a problem. Good clean separate supplies to coil, pump and ecu required.

Pump must be on a relay. Ecu earths this relay which needs an ignition live. ECu can't handle running the pump direct. Might be worth listening to or having a finger on the pump relay when you play to make sure it clicks on with ignition, and off after 5 secs if the engine is not turned over. Make sure the relay wiring and pump are correct.

CPS is polarity sensitive. Has to be wired the right way round.

Sounds like a stressed ECU/failing ECU to me.

 

Nigel

 

i had already run a separate earth to the coil pack just in case

Where is the 'earth' on a ford coilpack? I thought it had one 12V supply and an earth for the 2 coils, each switched by the ecu on separate channels. No constant earth wire. Check it's wired correctly. Edited February 27, 2015 by Longboarder