10 replies to this topic

[CPC]

Hi Guys

 

I had this problem last year and it does not really show up on a dyno.

 

My car starts and drives fine once cold but say once you have been driving for 10minutes at 60mph ish it starts to run rough/slight backfire through the carb. Once this happens if i pull over and open the bonnet the carb/inlet is always wet and freezing cold even in the warmer weather?

 

This is my setup below, i dont have the inlet manifold connected up and i have exhaust wrap over the exhaust manifold.  I have also noticed that my temp guage rarely gets above 1/4 up the guage even in the warmer weather?

 

 

What do you think i should try, plugs look good and the valve clearances are fine and i have no dizzy to worry about

 

Chris

[cal844]

Id be removing the exhasust wrap imo, also check the thermostat is the 88° one as thats what we need in the UK

Edited by cal844, 31 March 2015 - 09:39 AM.

[nicklouse]

inlet manifolds are always cold. it is one of the things that happens when you create a fine fuel vapour.

 

what spec is the engine? is your fuel pump upto the job?

 

is the stat. closing? (fitted)

 

run the heater hose through the manifold and see but i dont think it will change anything.

[CPC]

inlet manifolds are always cold. it is one of the things that happens when you create a fine fuel vapour.

 

what spec is the engine? is your fuel pump upto the job?

 

is the stat. closing? (fitted)

 

run the heater hose through the manifold and see but i dont think it will change anything.

 

Hi, its running a facet solid state fuel pump and i changed the small metal fuel filter that screws into it.

 

Basic spec its a 1380cc with swiftune sw10, HIF44 and a stage 4 head ( i bought it like it so not 100% whats been done to the head, still unleaded with using super unleaded and octane booster) Maniflow LCB and Megajolt. Im told the compression ratio is 10:69:1??

 

I dont think its a running lean and if i pull the choke cable out slightly once running it makes if worse if anything and im yet to check the thermostat.

 

Thanks Chris

[Stu.]

The false reading on your water temp gauge is probarbly a faulty sensor. Id just put a new on in. Easy & cheap job.

[CPC]

I am going to look into the thermostat because thinking of it the heater never gets much more than luke warm.

 

If it gets the carb gets wet on the spacer plate and the dashpot gets very cold

[Stu.]

Well put it this way. If the thermostat is sticking closed, that means the coolant is not circulating through the radiator, so with the engine running at temp, the coolant should get exterrmly hot as its not been cooled by the rad, so the gauge should go up quickly. You said your needle stays at 1/4 even in summer. If the engines not overheating, then its unlikely to be the stat, which is why I said its more likely to be a faulty sensor or a faulty gauge less likely).

 

The luke warm heater is likely to be a blocked matrix, or a faulty / blocked heater tap. I'd do the following -

 

Replace the temp sensor

Check for gauge reading to confirm this was the fault.

 

Run car to temp then feel the heater inlet pipe and where it goes luke warm. If its after the heater tap I'd replace it. If its at the matrix I'd remove the matrix and flush it out. Replace and check operation.

 

If you do suspect the matrix, you could remove the inlet and outlet pipes and plumb them in line to bypass the matrix. If the pipework all gets hot at normal tempeature you'll know for sure its the matrix thats at fault.

 

My temp gauge suddenly started reading 1/4 at normal temperature a couple of weeks ago. I replaced the sensor and it reads fine now.

 

Hope this helps a bit.

Edited by Stu., 31 March 2015 - 03:30 PM.

[carbon]

If your engine is running too cold you could try reducing air flow through the engine bay. The old approach was to fit a cover over the front grille, this was typically fitted in winter and then taken off in summer.

 

Connecting up the hoses to the inlet manifold should also help, what you are seeing with the carb are the early stages of carb icing. If you find your throttle starts sticking open that's probably it getting iced up, it does not have to be freezing weather for this to happen, just takes a cold damp day.

[Blatherskite]

Had a very cold mini some many years ago, and it turned out that the heater valve on the no. 4 end of the head had plugged with rubbery gunk. 20 mins later, warm Mini! Don't discount 2 or more failures together - they confuse the **** out of me.

[CPC]

Thanks, you have given me plenlty of things to try

[CPC]

I have changed the thermostat to a 88 item and now the temp guage sits bang on the half way mark, then i have removed the centre piece of exhaust wrap under the carb and touch wood the carb no longer appears wet.  I also topped up the carb dashpot and it was running better.

 

I have a 120mile round trip tomorrow so fingers crossed!!