Possible over fuel
Turbo Mini Forums

Car doesnt seem to rev past 5k in 3rd gear so changing to fourth it wont pull at all it just splutters and hold s back. Ive done a search about possible causes and in one of the topics it says either fuel pump or benross said it could be float needle valve which needs drilling out. We tried this and we couldnt get it to seal. I was told to check this you take the dashpot of and wind up the reg and no fuel should come out the carb, firstly is this correct. So instead i bought the part from avon bar and it still leaks fuel from the carb wen you wind the reg up. Took it for a drive anyway and doing the same as before and wen you brake hard the engine cuts out. you then need to turn the pump of and fire it over for a few times to get it going and then switch the pump back on. I spoke to avon bar and he said the fuel would come out of the carb wehn you wind the reg up he said it is normal, i breifly explained what problem i was having with the car and he said the pump may be to powerful as i told him it was a new pump but it was a injection pump, believed tobe 10 bar can the pump be to powerful and would it cause this problem? if not what could it be? i done a flow fuel test and it was pumping out a litre in 17 seconds.

Any help would be much appreciated

thanks

firstley you need to set the fuel pressure to 4psi with out boost

i hope you have got a rising rate fuel regulator *ie* one whitch rises with boost

say your boosting to 10 psi the regulator will compansate to 14 psi 4psi above boost check this.....

secondley remove the carb dash pot and turn the pump on, if fuel comes out there up the jet the float or needle vallve is fooked you must sorth thes two problems first in order

keep us posted

Hi,
It could be that your pump is over powering the reg, that's a lot of output!
Cheers,
Gavin :)

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he we have managed to turn the pump down abit by turning it to 9 volts. could this still be the problem? it didnt have any effect on the car what so ever.

The float valve doesnt leak and its a new avon bar one. Any other suggestions would be great.

i did notice the fuel pressure gauge flupuates and drops say 4 or 5 psi on full boost when the engine starts to playup ay 5 k and in 4th. other than that the gauge reads good on full boost the gauge shoots up to where it should be and stays their in 1st and 2nd. I am wandering if like you said the pump is to powerful causing pressure on the reg and due to the prolong accerelating the return line cannot get the fuel out quick enough either meaning the reg will drop in pressure. does this make sense or does it not work like this. im trying to think about all possible causes and the theory behind this would make sense. At the moment the return is just T in after the tank before the pump.

thanks for your help so far.

Matt

Hi,
No I would expect an increase in fuel pressure if too powerful.
Your drop in pressure would point to starvation.
The starting issue would say that it's flooding, which is confusing!
Things to look at first:
How is the fuel supply to the pump setup?
Is there enough breathing on the tank?
Remove the fuel cap when it cuts out, see if there's a vacuum in the tank.
Cheers,
Gavin :)

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yea but what i mean is if the pump is to powerful and the flow is to much on it then the return wouldnt be able to get away as quick so resulting in a build up in the reg, is this possiable.

the fuel setup what do you mean by this. the pump is mounted on in the boot and the return is t back into the line. it doesnt appear to build up in the tank and cause a vaccum, i have never opened up the tank and it been full of pressure.

i havent had chance to play about with the car today took a break from it but my dad had another quick look and he did change the butterfly valve, we took this out as i have a dump valve and their is a solid one in their now. have you got any other ideas. i would definatly say its fuel starving but where from and why. it always seems to stop pulling at 5 k in 3rd and when you put it into 4th its completely usless and pop from the carb. you can put it into 4th and load it up from slow speeds but its still the same when it gets to 4k. thats the same as 3rd gear you can load that up but when u get to 5k it stops too.


thanks

firstley!
you must have an independent fuel return line. if you Teed in the return line back into the inlet this may well be your problem

the pump must be the same one that came off a metro turbo
if the above is right the problem will lie with the regulator if the fuel pressure is all over, but unlikley

also if all the above is right try adjusting the carb mixture there is a lot of scope for adjustment there

keep us posted

Edited by BENROSS on 5th Aug, 2007.

sounds like my issues when it was far too rich.

i then got a misfire, which means no expansion of gases, which means boost drops.

try and find bud666's thread he posted just before riv run, very similar issues. Turned out to be the crap in-tank filter. Worth checking out...

Edited by Turbo Tel on 7th Aug, 2007.

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have changed the return line is now plumbed into top of the tank. adjust mixture slightly but i really dont think adjusting the mixture will make that difference cos it really does just stop pulling and its in same revs all time. its not the filter in the tank thats blocked because i dont have one in their anymore. thanks for your suggestions guys. its stilll the same though and i not sure what else to try. i obvouisly need to change the pump next to a proper metro pump or similar. their some cheap ones on ebay are they any good.

go for the pump the right one

ok ill source a new pump then. i hope this solves it.

i was thinking what about the timing side of things as i get the problem occuring at the same point in rev range all the time so it makes me wonder if its fuel because the fuel may make it vary? maybe its the mega jolt conponets or is this not likely. i believe i did use the laptop and take it down road a few weeks back but the degrees didnt drop or change? could this be a problem. Can i check the componets seperatly.

tried looking for pumps, is this the right one?

http://cgi.ebay.co.uk/MG-MAESTRO-MONTEGO-2...VQQcmdZViewItem

also some huy is selling cheap ones on ebay for 25 quid im guessing i should avoid these. although i remember reading a topic on these not to long ago. cannot remember the conclusion

T piece trick. Do a search.

Also, have you checked the condition of the lean-off pipe?

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

The timing didn't change with the megajolt you say? So it is running in fixed limp 10 degrees mode all the time? This will not help matters, you need to get it working properly.

sorry guys i think i may have suss it out. But now i have lost my clutch. bloody release bearing has gone so ill fix that today and try car again but basically i advance the timing as i checked what timing it was running. i advance it by 1 degree and it made a difference in 3rd gear didnt try four as i was on my way home from gettin pissed off because the bearing gone. so ill try car again and advance it maybe another degree ontop that see how it goes. it was running 26 degrees from 3.5k up to 6 k. so i changed the 5k boxes to 27 and tried that. is it safe to do that. to be fair 26 didnt seem high enough? what do you guys think ill keep you posted. cant believe it could just been timing all along.

Hi,
Careful here, you could be needing new pistons before the week's out!
I'd advise rolling road setup for full power timing adjustments...
Cheers,
Gavin :)

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it went for a rolling road and stuart couldnt get it to rev past like 4k either in 4th gear. so thats why when i advanced the timing another degree it went bit better surely he should have known to try that. it is odd he said when it was on rollers a few weeks back that it was pulling really well up to 4 k then just dipping and stopping. he reakoned cam timing or engine not being run it hard enough but ive never heard that before. plus the sam timing is ok!

Have you removed the filter off the pick up pipe in the tank and running an external pump pre-filter? It doesn't sound like a timing issue with 26 degrees those rpm. The extra advance you added may just of momentarily improved the problem.

yes i do not have a filter in the tank and i do have a filter before the pump.

tried the car the other day, friday. before i went away for the weekend and the car was doing the same again as usual but then all of sudden it got worse. and driving home from the strip i was testing it on it wouldnt boost at all. you would put your foot down and it would be flat as and would not pull at all. the boost gauge would read 0. It was very odd. came back from weekend away tried car again today and its still the same. it wont boost at all. is thhis problem linked to the problem i have been having.

im a very patient person but this is starting to get on my tits now all i want to do is drive the car and enojy it after all the man hours we have put it. im guessing from what i read its still the pump or reg that would cause this issue. I should really buy a pump and go from their but funds are now tight i no its not to expensive but with the car as it is i always seem to be shelling out on it. is their any other ideas first before the pump or is it a must.

oh yea when driving in 3 gear on full boost( when it was boosting) i could pull the choke out and it would creap past the 5k mark but then putting it into 4th i think it did end up over fueling but it definatly made a difference pulling the choke out in 3rd gear.

Today when it wasnt boosting i pulled the choke out and it boosted slightly and was all over the place but it did boost abit. then put choke in it went back to zero on gauge.

What would this suggest, i cant imagine it being to lean as ive adjust the mixture and tried that an no difference it just overfuels slightly on idle instead.?

please help, thanks for comments so far and sorry for long posts im just trying to explain all the details.

matt

Still having problems. i have bought a new regulator and this hasnt fixed the problem although it has stop the fuel gauge flucuating. have tested the pump again and again under load and normally doing a flow test also and it seems really good. i have also put a restrictor in fuel supply and has made no difference. surely it cannot be the pump side of things as the pressure is reading good. about 16psi fuel pressure and running about 12psi boost. when it gets into high revs in 3rd the car stops accelerating still withing the space of about 200rpm it stops completely pulling and the carb gets loader and deeper like its not getting enough fuel now. so maybe its the needle or something like that what do you guys think as i tried alot of other things.

recap the car stops pulling and makes this carb noise in 3rd gear at 5300rpm aprox and in 4th gear at 4300rpm approx.


any more help please thank you for your time.


matt

Stuart was spot on with my MJ? Did you check the timing with a timing light to make sure the MJ is reading TDC when it actually is.

If it isn't small adjustments need to be made in the map to compensate for this?

Edited by matty on 28th Aug, 2007.

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1/4mile in 13.2sec @ 111 terminal on 15psi

probably waaay off here, but what pipe have you got going to the inlet of the turbo? If it's the standard metty turbo one, it detirorates over time and crushes under boost. Might be that...

Ah too true could well be that....

A bit O/T but a mate of mine at work had this on his new Audi...lol It was dropped off at work, he drove 3 miles then had to call the RAC out. turned out there was a whole load of Audi's fitted with the wrong spec hose!

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1/4mile in 13.2sec @ 111 terminal on 15psi