22 replies to this topic

[Honda-Mini]

hi... my MPi mini keeps cutting out. its like a dead electrical cut, not a lack of fuel or misfire etc... its done it for a while, but on sunday it did it quite a few times and i noticed the Temp gauge shooting up way past the red to max stop. if i turned the ignition off and let the needle return down the car would start, otherwise it was a no go,
 
so my question is does the MPi mini have some sort of safety feature where if it gets too hot the ECU just has juice cut to it to stop the car?
I'm gathering i have a short somewhere doing this so ill be looking over the loom when i can, but just garnering opinion as these are newish to me...
 
i dont have a code reader as yet so cant plug it in, but i did have the Temp sensor changed for the MOT last week...
 
could it be shorting out when hot?
 
TIA
Martyn

Edited by Honda-Mini, 24 October 2019 - 09:55 PM.

[Mervyn]

Could be a bad earth strap. Perhaps the engine is finding an earth via the gauge?

Merv

[Honda-Mini]

Could be a bad earth strap. Perhaps the engine is finding an earth via the gauge?
Merv

Earth to the boot floor from battery was a bit threadbare.. hanging on by about 4-6 strands so I've changed it but not had chance to drive yet

I'll keep you posted thanks

[Honda-Mini]

So I took her out last night and initially all seemed cured... but nope

Another few cut outs and temp gauge reading right up past the red on the max stop. Seemed to happen when it's been sat running for a few minutes when up to temperature i.e., when it's got to 88° I nipped into a shop to get some oil, bumped into someone I hadn't seen and as I started the car, he came out so we had a bit of a chat for a couple of minutes then the car just died dead... no spluttering at all.. he's a mechanic and said "that sounds electrical " and I agree but where is the issue... the loom has had rubber zip tied around it in the usual contact points like clutch master cylinder, behind the tbi etc, and I pulled everything around with ignition on and it made no difference to the gauge.. about the only bit left now is the ecu and connector plug to check

[Honda-Mini]

Sprocket you seem to know about these sort of things. any insights? :)

[Wiggy]

I'd check the engine earth strap, which is located by the top engine steady. Also check the connections on the starter motor. Also clean up the ECU earth. This is located just to the left of the brake servo.

[Bat]

Hi,
The gauge signal comes from the ECU not the sender.
Sounds like you've got an ECU related problem be it a bad earth or the loom is damaged somewhere. Try checking down by the ECU someone else had a loom rubbed through on the bracket.
Cheers :)

[Honda-Mini]

cheers guys, will take a looksie when i get chance

[Honda-Mini]

ok, so i now have in my possession a nice ACR4 and leads/pods

 

still having the cutting out issue so i ran it up last night and when the car was about up to temp it just cut out... dead stop... also it was 'kettling' through the small hose to the expansion tank. i guess that would indicate the stat was open lol... also for reference, the stat, CTS, CTS Fly lead and expansion cap are all new

 

i got fault codes as follows (after clearing some i found, CTS one mainly) 

 

02 - Coolant temperature sensor circuit, Logged, sensor output voltage too low

05 - Sensor supply circuit, logged, sensor output voltage too low

13 - Fuel pump relay or purge valve or MIL lamp or communications circuit, logged, ECM ouput circuits

 

so, it appears that fault )" came back when it cut out, and they all appear to be regarding low voltage... so anyone in the know got any ideas? 

 

am i looking at a bad earth or something more sinister? 

would a high temp cut the engine dead? 

is there a way of snapshotting the data on the ACR4? i see it has a pc connection port? 

 

as it is, although the car is running well when it does, i cant take it out for fear of it cutting out and not restarting 

 

please help 

Edited by Honda-Mini, 07 October 2019 - 10:32 AM.

[Twincam]

On a side note, does your fan spin freely and work?

[burchy35]

I had something similar and it made the car cut out, especially on roundabouts. It ended up being part of the loom rubbing on the fuel pipes right hand side of the throttle body. And it looked like that part of the loom was from the temp sender.
So worth taking off the air filter housing and having a right good look around that area for any break in the loom.
Good luck,
Roy B

[Honda-Mini]

On a side note, does your fan spin freely and work?

Yep, if I whip the CTS plug off the fan kicks in as it should, so the ECU is signalling correctly

I went to run it up tonight, cleared down the errors and ran it up to temp... it kept cutting out dead again and losing signal to the ACR

Strangely, through all that, no errors have been logged so I’m surmising that now the battery is charged the low voltage warnings are gone :)
Also I presume that I am looking at either a) a bad earth, b) dodgy wiring to the relay pack or c) the pack itself (although I did take it apart and it’s mint... it was new about 1500 miles ago)

[Honda-Mini]

I had something similar and it made the car cut out, especially on roundabouts. It ended up being part of the loom rubbing on the fuel pipes right hand side of the throttle body. And it looked like that part of the loom was from the temp sender.
So worth taking off the air filter housing and having a right good look around that area for any break in the loom.
Good luck,
Roy B

will do Roy... along with a good old clean up of the earths, just in case :)

[Twincam]

How low was the battery? Thinking the voltage errors could also be from weak earths.

Check the main earth points (where the wiring mounts to the body near the inner wing) and give it a good clean just incase.

[Honda-Mini]

so I bit the bullet and splashed out on yet another new coolant cap. Fitted it and ran it up again... this time it started to boil at just below 105° and the fan cut in so it’s all working as it should electrically, however... like a muppet I went to adjust the coolant cap on the expansion tank and it acted like it was threaded (went on solidly when cold!) and when I turned it a little it shot off. Scalding my forearm with steam and hot water!

I’m wondering if the expansion tank threads are knackered causing a drop in pressure by letting the coolant cap move when it’s hot? Surely it shouldn’t be dodgy enough when it’s hot to blow clean off at the lightest touch?

As for the cutting out, I’m leaning to the main relay pack or loom to it, as there’s a loss of connection to the ECU and after a few seconds I here the fuel pump prime and the stepper (or something in that area) rattle a few times

Or an outside chance that the wiring looked tight to the map sensor?

Edited by Honda-Mini, 09 October 2019 - 10:56 AM.