Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Plus 4 starting from cold

Hello all
Just one month in to Morgan ownership and my first post with a tech question.

My 1990 +4 has the rover m series engine with some older fast road modifications - omex ecu piper cams etc. from cold it's particularly reluctant to start and once it has it feels as though it's goingg to die if I press the accelerator.

Once warm those issues disappear and the car runs smoothly.

Thought it was perhaps the temp sensor but replacement has helped only slightly.

Any obvious pointers or is it a "characteristic" of the engine in a Morgan?

John

If temperatures were colder I would have suggested icing of the fuel inlets.
Someone with knowledge of the Rover engine should be along soon.

It is a problem that I have with the Duratec fitted with throttle bodies and the Omex ECU. Careful tunining of the fuel map with the help of the technicians at Omex has improved the problem but I must wait for cooler weather to tackle it again.

If it has always been like that you may need to set the ECU to provide a richer mixture when the engine and/or air temperature is low.

Air leak on the inlet side?

It could be a number of things allied to the state of tune. I've had tuned cars some years ago which were a pig to run cleanly until they'd warmed up. It may be that a remap of the Omex ECU might help...it could have been fitted with a basic map, I didn't have such luxuries in those days!

Good luck John and welcome to both TM and your first Morgan!

Don't know so this is pure speculation but I recently looked at a 4/4 for someone with a gauge problem, it had 2 temperature sensors, one for the ECU and one for the gauge. Might be worth seeing if the M16 has two also? Just a thought. As others have said it sounds like its weak when cold, especially with your comment about feeling like its about to stop if you touch the throttle when on cold idle?

One of my Alfas required 4 squirts on the throttle and foot halfway down then operate the starter before it would start.

Thanks everyone
Think I will go back to basics and get the mapping checked. Everything else in a direct line from battery to engine is new or recently replaced

Spanner juggler - correct the M engine has a guage sender just below the sensor and that needed a connection clean up to get to work.

John

I have a 1997 +4 M20 with piper cams & OMEX fitted by Mog sport which was an absolute pain to cold start unless the battery was fullly charged. I have a trickle charger at home which was fine, but if we took the car away I would invariably have to get a jump start. As I would flatten the battery trying to start. Once started it would then start all day until....the next day.
It foxed Billy Bellenger who services my car. The trouble with cold start problems is it has to be cold to duplicate 'fault'. A couple of starts & you have to wait a long time to cold start.
In the end I took it to Troy Robinson at Northampton Motorsport Ltd 01604 766624 who has a rolling road. He does a lot of OMEX It is now a WHOLE lot better at cold start.
On a separate note mine has to be tweaked by Billy to pass the MOT emissions as well.

John ,this is an interesting one. My 89 Plus Four also has an Omex 710 ecu. Sometimes it churns quite a while before starting but other time starts straight away . May I ask how you start it? The form is, turn on ignition, wait until the fuel pump primes -you will hear a swish and then a audible click -then turn the key or press the start button. Do not touch the accelerater until the engine runs.