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Massive Flat Spot


Guest deebee 55

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Guest deebee 55

Hi All , i have posted about this before but now i have more information and require your Help ,

Just to recap this is a new build started after lying for ten years or more and now not far off completion ,

 

The engine starts and runs on tick over , (not if i touch the throttle ) it does take a few goes before that but when it starts it will cut out once or twice and then as it gets warm behave quite well the problem is it then has a massive flat spot if i try to do anything with the throttle ,

if i get over the flat spot and it will rev well ,

 

now here's the thing i have a sykes pickavant diagnostic that tells me there are no fault codes and all the sensors , coil ,injectors are all working within normal peramatures ., iv'e been on this for days and days now and not getting anywhere fast so before this ends up killing me or in the bin to be replaced with a v6 ford can anyone recall this happening to anyone else,

any replies will be greatly received , could this be a problem with the fuel pressure regulator ??

cheers

Dave

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The fact that you can get it to run after a fashion leads me to suspect it's not an ignition problem but more likely to be a fueling problem. It's certainly worth investigating. Firstly what components do you have in your fuel system. What high and low pressure pumps? What filters? What fuel regulator? What fuel injectors and rail? Secondly can you draw a simple diagram to show how they are laid out and their relative positions? Then how are the pumps wired up?

I suspect that fuel supply is the problem. Possibly electrical pressure or volume. All can be checked once you focus on each possibility.

One of the cheapest 'investments' is an inline fuel pressure gauge. Ebay £25 or so like thishttp://www.ebay.co.uk/itm/POWERTEK-FUEL-PRESSURE-GAUGE-KIT-INLINE-ADAPTOR-8mm-HOSE-UNIONS-/162254016634?hash=item25c717d07a:g:feYAAOSw1DtXH4oK

Then you can see what's happening to fuel pressure and flow as it happens. But draw us a picture and flood us with information first. And do trace the system on the car, not assume it's good and put together right.

 

Nigel

 

Probably should look something like below pic.

post-21-0-77378300-1479760186_thumb.jpg

Edited by Longboarder
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Guest deebee 55

Thanks Nigel the rest of your post just popped up , as i said its a new build as supplied by RH , looks nothing like the that , RH supplied the super spec as a kit as as i can understand most people who bought the kit put it together as supplied and it ran without to much of a hitch thats not to say they weren't improved on at a later stage but should run ok as the were purchased ,

this is a very simple design but should work ............immersible pump in tank (new) two fuel lines to the front of the car one running to a fuel filter and then on to the fuel rail the other coming from the fuel rail to the regulator and back to the tank ,

 

lived and worked in plymouth i loved it

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Guest mcramsay

definatley a fuel issue, either too much or too little, or too much air! I would check fuel pressure is correct first, and change the filters if the car has been stood a while you could have flushed some crud from the tank. Check you have good fuel flow aswell, if all good might be worth cleaning the Idle control valve if the car won't idle correctly sort that first !!

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Hi,

 

I had issues similar to yours after my car had been standing for 7 years. It was due to fuel, sender seized up, tank full of crap, fuel line degraded . Cleaned tank out , new sender, new fuel line and filter. Problem solved. Good luck

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Guest deebee 55

Thanks gusty i appreciate you time , this car although old in the respect it was purchased ten -twelve years ago is being built for the first time with all new parts out of there boxes so to speak as supplied by RH it was not put together and then left ,

i started to build it six weeks ago so before that the car stood in a back garden but all the components were dry stored

i'm sure the answer is a simple one , its just finding it ,

is yours a standard super spec ? the question asked by nigel , does it have high and low pressure pumps etc etc whilst seems perfectly valid don't seem to apply to the standard super spec or do i need to rush out and spend loads converting it to get it to run , if yours is standard i;e t series rover and as it came from RH ........do you have all that on your car ?

 

sorry just noticed yours is a 2b but i''ll leave this up incase others have any clues

Dave

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or do i need to rush out and spend loads converting it to get it to run?

No you probably don't. The reason I asked you to trace the fuel components, list them precisely and draw a pic of how they are assembled and in what order is so that I and others can see if what you have done has any chance of working.

For instance someone used to running carbs might put the fuel pressure regulator between the pump and the fuel rail as you would do with carbs. In an injection system the fuel regulator comes after the fuel rail.

I would advise doing a pic for your own benefit. Easier to visualise.

I would also suggest a pressure gauge temporarily in line before the fuel rail so you can see pressure (and an idea of flow) under running conditions.

 

Nigel

 

Is this what you are running?

post-21-0-74284000-1479813893_thumb.jpg

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Guest deebee 55

Thanks to everyone who replied , and thanks again for your time Nigel ...........i have been doing what you suggested and now know the problem ,

Last weekend i fitted a new clutch and in order to get the gearbox past the footwells i had to drop the back of the engine a tad ... i must have put strain on the fuel feed pipe because as i traced it back to the tank where it leaves the tunnel and up to the tank it had a kink in it where the pipe must have tried to stretch ,

those pipes are not good when it comes to corners and once kinked thats it ....all replaced and working fine now so thanks again .

Dave

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