FIESTA XR2I MISSFIRE..ANY FORD NUTS PLEASE HELP :)
FIESTA XR2I MISSFIRE..ANY FORD NUTS PLEASE HELP :)
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STINTON911

Original Poster:

34 posts

199 months

Wednesday 22nd July 2009
quotequote all
Hey everyone, im John and I have a 1990 H reg CVH 8v Xr2i.

I have just spent the last month rebuilding the engine of my little fez..
New pistons, rings, head skimmed, full head overhaul and a brand new kent cam...
I did this because the engine was miss-firing when it started and will not drive ..plus it needed a good service..
I have renewed all the gaskets, done an oil and filter change, new spark plugs , coil pack and HT leads all of which have a good spark!
I thought it may be a fueling problem, so i took the fuel line of the injector rail and turned the car over into a plastic container. it seemed to be flowing out fine and very clean.
when I manage to get the car to start the more I put my foot on the accelertor the less it revs and wants to cut out, but if I tap the peddle quickly it seems to pick up, but will not go past around 3-4000 rpm.
also if I take the vacume hose off the EFI unit going to the MAP sensor it seems to sit and idle on its on fine and will rev satationary all the way to the limiter, but still has no real power.
I have changed the MAP sensor with no luck.. I am really puzzled can anyone help as i have spent alot of money on this car and its getting to me now...
Im pretty sure its nothing mechanical .. so its either electrical or one of the sensers...

I also have pics if anyone wants to see the car going back together,,,

PLEASE HELP!!!
cheers John

oakdale

1,977 posts

224 months

Wednesday 22nd July 2009
quotequote all
Could be many things but fuel pressure springs to mind, although the fuel flows out well with the pipe removed, this doesn't mean there is suffient pressure.
Also a blocked exhaust silencer is a possibility.

Edited by oakdale on Wednesday 22 July 22:42

Rollcage

11,345 posts

214 months

Wednesday 22nd July 2009
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Have you got the timing right?


paintman

7,846 posts

212 months

Thursday 23rd July 2009
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Whilst you may eventually cure the problem by continuing to change parts at random, it is as you have found a very expensive way to do it and you still haven't got anywhere. Its a very common approach on many vehicle forums!
Have you considered getting it looked at by someone with proper diagnostic equipment?

STINTON911

Original Poster:

34 posts

199 months

Saturday 25th July 2009
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Hi everyone ..cheers for your feed back..

I have tried to call out 2 mobile mechanics now, both of which told me they didnt have the right equipment to put the diagnostic kit onto my car...I am not sure if this is true but will keep trying..

I do have a straight threw magnex exhaust on the car which I dont think has any problems.. this runs off an ashley performance manifold...

Im pretty sure the timing is right, as my uncle is an old capri boy and is pretty good with that sort of stuff (I had him help) and we turned over the engine by hand about 4-5 times before turning the engine over by key.. bearing in mind I had the same problem before I decided to rebuild the engine, thinking I would get rid of it that way.

The car seems to be running extremely rich , and i am almost positive it is fuel or ignition related..

STINTON911

Original Poster:

34 posts

199 months

Saturday 25th July 2009
quotequote all
I have posted some pics of the rebuild iun the FORD section under ..My.xr2i.... STINTON911
if anyone wants a look.

john

oakdale

1,977 posts

224 months

Saturday 25th July 2009
quotequote all
If it's running extremely rich, it's worth checking the fuel regulator on the end of the fuel rail above the injectors.
The diaphragm can split on this, causing neat petrol to be drawn in through the vacuum pipe.
Just disconnect the pipe when the engine is running to see if there is any improvement.

Zad

12,934 posts

258 months

Sunday 26th July 2009
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In addition the the above:

Maybe the injectors are leaking? Alternatively, it may be that the ECU is getting wrong information from the sensors. I'm not sure what sensors are on that engine, but faulty air mass meter, engine temperature or throttle position sensor would cause it to over-fuel. Over-fuelling would also cause it to not rev freely.

Pumaracing

2,089 posts

229 months

Sunday 26th July 2009
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The fuel pump needs to be tested under pressure not just flowing out of an open pipe. That means the pressure regulator needs to be in the circuit and you measure the flow coming out of the return to the tank. There should be at least 1 pint a minute at 3 bar.

If the cam and ignition timing are correct (easily checked), HT leads on in the right order and you're getting a good spark at each plug and at the right time then it must be fuel. If the connector between the in-tank fuel pump and the tank outlet is perished you can lose fuel pressure although it'll still flow well enough when there's no regulator to work against. Or it could be the pump itself or a blocked filter.

STINTON911

Original Poster:

34 posts

199 months

Sunday 26th July 2009
quotequote all
oakdale said:
If it's running extremely rich, it's worth checking the fuel regulator on the end of the fuel rail above the injectors.
The diaphragm can split on this, causing neat petrol to be drawn in through the vacuum pipe.
Just disconnect the pipe when the engine is running to see if there is any improvement.
Hi mate.. yes this seems to maybe have something to do with it.. when I manage to get the car to run if I disconnect the vacume pipe off the EFI unit going to the MAP sensor it will run alot better and rev up to 6-7 grand and doesnt need me to keep tapping the throttle to stop it cutting out.. still runs lumpy but defo better than before.. do you reckon it is the fuel regulator then?

oakdale

1,977 posts

224 months

Sunday 26th July 2009
quotequote all
I mean disconnect vacuum pipe from the fuel regulator.

STINTON911

Original Poster:

34 posts

199 months

Monday 27th July 2009
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Ok mate will do.. il let you know how i get on ..

cheers john