Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Plus 8 will not start when warm

Hi all.
My plus 8 from 1996 have a problem to start when its got warm. A swedish summer "cold" start goes fine, not problem. It runs smooth no strange idle problems. But if I stop the engine it wont start again until its cooled down. I have cleaned the idle stepper motor. A new battery is on the buying list tomorrow.

Does anyone have tip on where I can continue the search for a cure for my plus8?

Can you connect a OBD 1 reader to my Plus 8.

This may be worth a read

http://en.wikipedia.org/wiki/Crankshaft_position_sensor

"The first sign of crankshaft sensor failure, usually, is the refusal of the engine to start when hot but will start again once the engine has cooled."

I think your +8 is likely to be the same as mine, the previous post said crank position sensor may be at fault I do not think there is one as our type has a distributor to do this. Have a look at 14CUX-efi if your has this type. Having had a quick read I would suspect the engine coolant temperature sensor, as the ECU uses this to richen and weaken fuel so if it way out then it might stop hot restart.

Please let me know how you get on, would be interested to know what the solution is. Hope this might help.

Hi. My ECU is marked "AMR2175" "14CUX" "80405A" and its made in november 1995.
My plan is to test the sensor by "boiling" it to the different temperatures and check the resistance in the sensor according to the table on the linked webside. If ist not reacting acc to the spec get a new one from England and replace it. If is react acc to spec, hmmm, back to square one.

I will update what's wrong with my +8.

//Fredrik

Hi MrMagoo, it's typical if there's to much fuel which could be a result of what AJSki2fly above suggests. I suggest you check the old fashion way; press the accelerator to the floor, crank the starter and wait for firing. If it doesn't work, try with accelerator half way to the floor and try the same again - if the problem is too rich mixture, it should at least fire on a few cylinders, maybe even start.
(hälsningar från Östersund)

Hi all.
I boiled the sensor and here is the results, numbers inside ( ) is the value it should be:

20 degree C : 2280 Ohm (2500)
40 : 1760 (1200)
50 : 1330
60 : 1050 (600)
70 : 813
80 : 930 (350)
90 : 1114
100 : 790 (175)

So, looks like I have a broken engine cooling temperature sensor.

Well cooked Mr Magoo, I think a visit to shops for a new sensor is required.

Yepp, already ordered one from Mister-Auto.se at a cost of 1.3GBP.

I´ll get back to the forum to confirm that a new sensor solved the problem. Just for the record.

I hope that this is the issue resolved, I made and educated guess so hopefully this will sort it.

Hi
Today I have tested my car with good result. It run like it should and it started when I started it warm again.
I´ll also have to correct a fault that I saw about the cost of the sensor. It´s not 1.3GBP it was 13GBP. I have to blame my fat fingers. They do not always match those small smartphone screens.

//Fredrik