Engine cutting out intermittently - Fuel Problems?
24 February 2005, 09:55 PM
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Engine cutting out intermittently - Fuel Problems?
Can anyone help?
I have a problem with intermittent hesitation or cutting-out. This occurs at any time, at low or high revs and wide throttle or just pottering. The engine either hesitates or looses power for a second or two or occasionally cuts right out and I glide quietly to a standstill. After a few minutes I can start and move off normally. Bit embarrassing tonight, cut halfway past when overtaking and had to fall back!
It feels to me like fuel starvation. There is no knocklink activity and I think no lights on the AFR.
The thing is I have just fitted an uprated fuel pump (Henko 255 l/m) and wondered if it may be producing too high pressure for the OE regulator?
More likely, perhaps, could there be an air lock somewhere? I must try running with the fuel cap off to see if the tank ventilator is blocked.
And the fuel consumption has increased, down from 21 to 19/20 which implies higher fuel pressure?
Or is it something totally different?
Car is a MY99 UK with full decat, Tek 2.5 and VF24 running 1.2 bar. Goes well when running.
I have a problem with intermittent hesitation or cutting-out. This occurs at any time, at low or high revs and wide throttle or just pottering. The engine either hesitates or looses power for a second or two or occasionally cuts right out and I glide quietly to a standstill. After a few minutes I can start and move off normally. Bit embarrassing tonight, cut halfway past when overtaking and had to fall back!
It feels to me like fuel starvation. There is no knocklink activity and I think no lights on the AFR.
The thing is I have just fitted an uprated fuel pump (Henko 255 l/m) and wondered if it may be producing too high pressure for the OE regulator?
More likely, perhaps, could there be an air lock somewhere? I must try running with the fuel cap off to see if the tank ventilator is blocked.
And the fuel consumption has increased, down from 21 to 19/20 which implies higher fuel pressure?
Or is it something totally different?
Car is a MY99 UK with full decat, Tek 2.5 and VF24 running 1.2 bar. Goes well when running.
Last edited by wintn; 25 February 2005 at 07:39 AM.
25 February 2005, 10:58 AM
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My car did this last week. engine just stopped. started it again pulled away...15.......20 mph just stopped again. 10 minutes later was able to start the car and away i went. no problems since.
doesnt appear anybody has the foggiest why it did it tho!
Matt.
edited to say its an my00 with tek 2.5, ITG panel filter, scoobysport system
doesnt appear anybody has the foggiest why it did it tho!
Matt.
edited to say its an my00 with tek 2.5, ITG panel filter, scoobysport system
Last edited by Matt_Davies; 25 February 2005 at 11:00 AM.
25 February 2005, 08:27 PM
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Well, I loosened the fuel cap so it did not seal and had no problems all day. Looks like tank ventilator not working causing vacuum in tank.
Anyone know how the tank vent system works? I believe it keeps a low level of vacuum in the tank to prevent petrol fumes getting out.
Anyone know how the tank vent system works? I believe it keeps a low level of vacuum in the tank to prevent petrol fumes getting out.
05 March 2005, 04:40 PM
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Update - finally sorted.
When I loosened the fuel cap and it appeared to solve the problem it was actually filling it up with fuel that solved it!
To cut a long story short, the new uprated fuel pump (Henko racing) had a pickup/filter that sat 2 inches (5 cm for those that can't remember inches) higher than the original. Hence as the fuel level reduced in the tank (quickly being an Impreza turbo!) the pump was failing to pick up intermittently. Below 1/3 full it would stutter after acceleration or cornering and by the time there was only a gallon or so there it would stop completely.
Fitted original longer pickup and problem is solved. Needed a bit of cutting & a cable tie to fit which is why I did not fit it originally.
When I loosened the fuel cap and it appeared to solve the problem it was actually filling it up with fuel that solved it!
To cut a long story short, the new uprated fuel pump (Henko racing) had a pickup/filter that sat 2 inches (5 cm for those that can't remember inches) higher than the original. Hence as the fuel level reduced in the tank (quickly being an Impreza turbo!) the pump was failing to pick up intermittently. Below 1/3 full it would stutter after acceleration or cornering and by the time there was only a gallon or so there it would stop completely.
Fitted original longer pickup and problem is solved. Needed a bit of cutting & a cable tie to fit which is why I did not fit it originally.
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