40 replies to this topic

[eric.sen]

Hello everybody,

I want to start a new topic about a very common problem on MPI Mini :

 

The car is kangarooing when the engine is hot below 1700 or 2000 rpm on 2nd or 3rd gear.

But only when the engine is hot.

 

There is many topics of this common problem (called car jerky, kagarooing, spluttering etc...)

 

For my part I changed those parts to try to solve the problem :

 

- oïl and filters (servicing)

- Oil temperature sensor

- Coolant temperature sensor

- crank position sensor

- throttle TPS sensor

- Trying to find air leaks near the throttle body

 

It changed nothing....

Edited by eric.sen, 24 May 2017 - 09:24 AM.

[Midas Mk1]

It's an MPi thing, most owners have it unfortunately, only happened on me on slow part throttle when crawling in traffic, takes abit of clutch control to smooth it out. 

 

When it next happens, try giving two hard stamps on the throttle, normally clears it for me.

Edited by Midas Mk1, 24 May 2017 - 09:37 AM.

[eric.sen]

I also invest on an ACR4 pickavant

 

But it found no fault codes

[eric.sen]

Who has got this problem on the forum ?

[MacGyver]

Cruising at 50kph or in traffic.
Playing with clutch seems to cure it.
Bit like the gearbox was made with ruber-bands... I think the 2.7fd has something to do with it (or doesn't help), just always drive with your foot down and screaming around corners... 😀

[DeanP]

My old Rover 200 used to do this, turned out to be the rotor arm after chatting to a Rover technician. 

 

Bought a replacement and problem solved.

 

It was a while ago, I may add.

Edited by DeanP, 24 May 2017 - 08:35 PM.

[MacGyver]

Mpi... No rotor...
Sadly... 😑

[DeanP]

Mpi... No rotor...
Sadly...

 

lol.

[Screwdriver]

It's not just an MPi issue. I experience this, even on warm days, on my Spi. Conversely, it happens mostly when the motor is warming up and disappears once warm. Could be because I have a cone filter instead of the stock airbox? 

[MacGyver]

Just to add, Noticed it was worse with the original 13" heavy original rims too... its like being towed with a bungee rope/rubber-band...

[Scott MPI]

I've done a lot of work with this problem, its like nothing makes a difference whatever you try 

 

it will be the camshaft timing to far advanced, slacken the exhaust valves and take for a spin, if it feels better your on the right path,

 

I got a adjustable cam kit in the end and adjusted it   ( its the injection method of moving the distributor an a carb engine) 

 

if you imagine, the spark will ignite at a set time from the flywheel anyway, whatever the valve timing is

 

car will run loads smother, not over heat/ fan on a lot ect    

 

Cheers

 

Scott

[eric.sen]

So you mean that every MPI where kangarooing new from the factory ?
Or is there a parts that is used or a setup to do ?

[Scott MPI]

Well there's a lot that suffer the same complaint on here, I had a sportspack 3 years old with 10k, that did the same thing 

 

was diagnosed to be the wire to the temperature sensor, but made no difference !

 

Few tests you can do,  does it get unusually hot, does the exhaust pop when hot, the hotter it gets the worse it is 

 

Give the tappets a bigger Gap, say 25 thou, ( essentially changing the valve timing a bit ) 

 

wont take you long, if you feel a difference,  even slightly- then it needs adjusting

 

I fitted a Lightened Vernier Duplex Timing Gear & Chain Set , saves time undoing the crank and cam bolts in the future 

[hennasxi]

Interesting thread as I know of lot of MPi owners who complain about this  - one of mine did it, now sold, never cured it !!  The one I still have does not do this at all, so proof you can have an MPi that doesn't Kangeroo !!

 

I was going to try new injectors in the one I sold, still have some new old stock ones as spares.  The theory on the injectors was that at certain rev ranges they are not squirting the fuel correctly leading to the car not burning the fuel as efficiently as it should, then the sensors pick it up and try to correct it, causing the kangerooing to cycle until you dip the clutch or put your foot down to break the cycle.

 

Nice theory, I never got to swap the injectors to prove it though.

 

The one I did have that did it had engine work done on it (head gasket etc), and similar to Scott mentions, the exhaust did used to 'pop' so perhaps the valve timing is the cause of all these issues.  Shame I don't still have that car as I could have tried all of the above and fed back my findings.

[eric.sen]

Thanks for all your answers.

Still try to find the problem.

 

Somebody talk about the "tappets" / but if you change with a 1.5 lift high lift tappets ; does it helps or change the RPMS when the car is kangarooing ?