bl1300
Posted a lot
Posts: 1,678
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Jun 22, 2011 16:42:06 GMT
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Mate of mine is having a little problem with his 1998 Colt 1.6 GLX.
The car is modified from standard spec.
It has lowering kit
High pressure fuel pump and regulator valve
KandN induction kit
and a heavily modified exhaust, Back both distinctly smaller than standard and no mid silencer.
The problem he is having is that when you try to pull away the car judders and shakes, the revs stay flat and after a few seconds it pulls away. He says it feels down on power as well.
So we had it in the workshop today but can't seem to find the fault.
Fuel pressure at idle is 2 bar rising to 3 bar when revved.
It revs no problem at all in neutral.
All spark plugs seem ok and we cant detect any air leaks. Even spraying easy start all over the manifold with the engine running didn't cause the revs to rise.
We found that the coolant sender wire had broken so replaced that and no difference other than a working temp gauge confirming temp is normal.
Appreciate any advice.
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Current fleet.
1967 DAF 44
1974 VW Beetle 1303s
1975 Triumph Spitfire MkIV
1988 VW LT45 Beavertail
1998 Volvo V70 2.5
1959 Fordson Dexta
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Jun 24, 2011 16:19:00 GMT
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I would try sacking off the barry mods to his fuel pump/regulator, if you just pump more fuel in without doing anything else, you wont go any faster, just burn more juice. PLus its probably made in china from monkey metal. Refit the original bits and see if the symptoms have changed at all.
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1974 Lancia Beta Saloon
1975 Mazda 929 Coupé
1986 Mazda 929 Wagon
1979 Mazda 929 Hardtop
1982 Fiat Argenta 2.0 iniezione elettronica
1977 Toyota Carina TA14
1989 Subaru 1800 Wagon
1982 Hyundai Pony 1200TL 2-dr
1985 Hyundai Pony 1200 GL
1986 Maserati 425 Biturbo
1992 Rover 214 SEi 5-dr
2000 Rover 45 V6 Club
1994 Peugeot 205 'Junior' Diesel
1988 Volvo 760 Turbodiesel Saloon
1992 Talbot Express Autosleeper Rambler
2003 Renault Laguna SPEARS OR REAPERS
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Jun 24, 2011 16:32:23 GMT
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What type of fuel system does the colt have? Because if it's MPi the fuel pressure looks too high (should be nearer 15psi/1 bar) but if it is multipoint it could be a touch too low (I'd expect 45-60psi, 2-3 bar) and also I wouldn't want to see a change in pressure with revs unless the car is turbocharged and on a variable pressure regulator - Normally the rail pressure is constant and the fuel requirement set by pulse width modulation (PWM) at the injector.
As a first step, xbollox' idea of binning the aftermarket kit sounds about right to me, after all the fuel rail (or monopoint) will contain a pressure regulator anyway.
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To get a standard A40 this low, you'd have to dig a hole to put it in |
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bl1300
Posted a lot
Posts: 1,678
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Jun 24, 2011 19:19:35 GMT
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Well it has a single injector per cylinder.
The fuel system mods have been on the car for 2 to 3 years and this problem is far more recent. we did swap out the pump for an original spec one but it made no difference.
There is a tap valve on the regulator that allows you to adjust the fuel pressure as well
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Current fleet.
1967 DAF 44
1974 VW Beetle 1303s
1975 Triumph Spitfire MkIV
1988 VW LT45 Beavertail
1998 Volvo V70 2.5
1959 Fordson Dexta
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Jun 24, 2011 19:25:43 GMT
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OK, have you tried swapping/checking the mass airflow sensor and the throttle position sensor? There is also an intake air temp sensor (sometimes built into the MAF body). Any of these could be messing up the mapping and cause poor running.
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To get a standard A40 this low, you'd have to dig a hole to put it in |
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bl1300
Posted a lot
Posts: 1,678
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Jun 24, 2011 19:36:22 GMT
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Haven't tried that yet but will give him a shout tomorrow. Incidently my PCMSCAN software annoyingly is picking up no fault codes
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Current fleet.
1967 DAF 44
1974 VW Beetle 1303s
1975 Triumph Spitfire MkIV
1988 VW LT45 Beavertail
1998 Volvo V70 2.5
1959 Fordson Dexta
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Jun 25, 2011 20:20:40 GMT
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The problem with trouble codes is that they are largely concerned with emission control, and often you don't get a reported fault for a dud sensor. I'd be recording some live data and graphing it to look for odd responses.
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To get a standard A40 this low, you'd have to dig a hole to put it in |
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bl1300
Posted a lot
Posts: 1,678
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I have got the software to do that but I'm going to have to work it out first
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Current fleet.
1967 DAF 44
1974 VW Beetle 1303s
1975 Triumph Spitfire MkIV
1988 VW LT45 Beavertail
1998 Volvo V70 2.5
1959 Fordson Dexta
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RobinJI
Posted a lot
"Driven by the irony that only being shackled to the road could ever I be free"
Posts: 2,995
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Any luck with this yet?
That fuel pressure and rate of increase sounds almost identical to the 1.6 single-cam v-tec civic a friend of mine used for his college project. Rising rate fuel pressure regulators aren't necessarily only for turbo stuff. A Haynes should let you know the desired fuel pressures, with and without the vacuum pipe to the regulator connected (so idle and full throttle effectively)
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