Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Hot and Bothered, and spitting the dummy.

Sorry gents, forgot to mention that I did the ignition leads at the same time as the coil last time..

Then I wonder if Your computer is sending a signal properly. Check GOOGLE and read "How To Test ZETEC ignition". There is more to this. A diode is hooked up to the ignition to insure the coil pack is getting the necessary signal. So if You did this when all fails at least it may give you some information. I have, but not using, a ZETEC EFI. There are at least 2 heat sensors maybe 3. Don't know enough about EFI, but I would find out if I was in your situation.

Check with a few of Your Aussie friends. Roger Shawyer, Richard Rogers, John Merton and/or Vern DaleJohnson. They will tell You that Button is not too bright, but is tenacious as hell!

When I installed a ZETEC engine in My '61 DHC I used Weber carbs for a reason. I wanted something that worked and did not come out of a sedan. Another words I pitched the EFI and the Ford computer. If I really wanted EFI I would go to Throttle Bodies and a computer designed for this rig. Actually Money was My problem. I had the Webers and manifolds already given to Me. I did not want to spend money for something I felt I didn't need. Now don't get Me in the Carbs vs EFI discussion. There is not doubt in My mind that EFI is a better option. But not a sedan efi. One built for performance not emissions. Hope I am not sounding like "I know it all". I don't!!!!!!

We can discount dirty MAF sensor, plugs, coil packs and leads from the suspects. I'm now thinking TPS....

Lachlan,
I would still not discount crap in your fuel tank. Do you have an electric fuel pump or mechanical. I got a dirty load of fuel from a reputable large dealer in my wife's shopping trolley and it cost me $700 to clean it out. Servo took no blame. Any hills or surging could stir up the dirt (or water) and then cause spluttering when it levels out.

Good way to learn how a Morgan works

The thing that got me was that it was surging. If it was fuel, wouldn't it be more of a splutter/starvation thing?
This is at idle:
https://youtu.be/qMq-T4Rljmw

I have had two thoughts on this issue.

The first one is to wonder if the fuel filter is uni directional and if so was it installed the right way round.

After watching your video I had different thought. The Duratec engine uses a bypass air valve for idle control and before I changed to throttle bodies I had a problem with this valve. The Zetec engine also uses a similar system. Basically the principle of the thing is that when the engine is cold, or the aircon (I know you don't have aircon) is turned on, etc, the valve opens to let more air into the system, a little like opening the throttle a tiny bit. When the engine is cold it is already getting more fuel so that all balances out and when the engine is hot the ECU, via the sonda lambda sensor, sees a weak mixture and adds more fuel to compensate. In addition to this the spark may be advanced and retarded to help adjust the idle speed.

To my mind you have all the symptoms of a sticking idle air control valve. I found this video in a Google search.


Might be worth reading this too: http://www.gomog.com/allmorgan/ZetecIdleIssue.htm

For what it is worth; I have a TPS on My Webers. It allows Me to access the 3D ignition map on the Ignition computer. I have tested with the TPS connected and without the TPS connected. Does not effect idle and I can not find any difference in performance. I suspect the TPS has an effect on Fuel Consumption and/or Emissions.

My 2000 Jeep Grand Cherokee has this symptom. From what I read it is the IAC that is causing the problem. I have ordered a new IAC. We will see if this cures the problem.