Low fuel Pressure
Discussion
Still got the old severe shunting problem on light throttle.Engine recently blue Printed with a new sports cam, been checked at horizon motor sport today and they can find nothing wrong apart from the fuel pressure is down to 26 psi. Is this likely to cause the car to jerk at light throttle ?
v8 racing said:
I assume you guys have tried disconecting the vacum advance pipe to the dizzy? this will substantionaly help with the shunting
Yeh mine is disconnected with a rubber cap over the vac unit on dizzy.it had a flat battery for a month before i bought the car , the guys at Silverstone preformance said this can sometimes happen and the ECU needs to learn again ?, make any sense?. Has new leads as well , feels like fuel /air issue to me.
>> Edited by Rum Runner on Wednesday 15th March 11:01
>> Edited by Rum Runner on Wednesday 15th March 11:04
sorry guys it has a rubber cap on the other end as its a serp engine and yes the vac pipe is still on just went to check. Does it not affect the low down power though , as with it disconnected you are depending on only the weights.
Did the ohms test on the coolant sender , o.k and fuel temp sender .o.k. Checked timing 2 degrees out. cleaned plugs and regapped at 35 thou, the bible said quotes of 32 and 35.Plugs on the black side but the car has done a couple of cold starts without a run.Stepper clean , throttle butterfly clean,leads good, had injector cleaner through, it is not down on a pot as they all sound even when each lead is connected / disconnected.Ecu disconnected , new air filter. Ticker over fine just a little lumpy, goes first turn of the key cold or hot, pulls sweet ,sounds sweet, just does not like light throttle below 2000rpm, shunty.Can't see what it is thats causing it, i am running it on BP super 97 or Esso super 97, no shell or tesco near by, could this be the problem.
Oh its an 4.0 Hc
I spoke to the previous owner who said it did not used to shunt, and Rob Ingleby tested the car for him at start 2005 and said it was one of the strongest 4.0 cars head driven. (I have the report from Rob). So I don't want to upset to much on the car !!. It had a full service before i bought it then it stood for a month with a flat battery, and was told the ECU can loose its settings and go back to default, and it may need to learn again ?.
>> Edited by Rum Runner on Wednesday 15th March 17:34
>> Edited by Rum Runner on Wednesday 15th March 17:37
>> Edited by Rum Runner on Wednesday 15th March 23:50
Did the ohms test on the coolant sender , o.k and fuel temp sender .o.k. Checked timing 2 degrees out. cleaned plugs and regapped at 35 thou, the bible said quotes of 32 and 35.Plugs on the black side but the car has done a couple of cold starts without a run.Stepper clean , throttle butterfly clean,leads good, had injector cleaner through, it is not down on a pot as they all sound even when each lead is connected / disconnected.Ecu disconnected , new air filter. Ticker over fine just a little lumpy, goes first turn of the key cold or hot, pulls sweet ,sounds sweet, just does not like light throttle below 2000rpm, shunty.Can't see what it is thats causing it, i am running it on BP super 97 or Esso super 97, no shell or tesco near by, could this be the problem.
Oh its an 4.0 Hc
I spoke to the previous owner who said it did not used to shunt, and Rob Ingleby tested the car for him at start 2005 and said it was one of the strongest 4.0 cars head driven. (I have the report from Rob). So I don't want to upset to much on the car !!. It had a full service before i bought it then it stood for a month with a flat battery, and was told the ECU can loose its settings and go back to default, and it may need to learn again ?.
>> Edited by Rum Runner on Wednesday 15th March 17:34
>> Edited by Rum Runner on Wednesday 15th March 17:37
>> Edited by Rum Runner on Wednesday 15th March 23:50
GreenV8S said:
Rob Ingleby ... said it was the strongest 4.0 car head driven.
Well there's a surprise!
Yeh I know that old story, anyway that was for the previous owner. i just read his old report It does go better than some of the other 4.0 chim's drove but this is the only H.c i tested so i don't know what they usually feel like , but i think it is a little out somewhere myself on the fuel/air side of things.
just remember chaps a little to much advance around those revs will cause that hunting jerking feeling,dont forget the dizzy is mechanical and the bob weight springs stretch with old age, causing ignition timing to be slightly over-advanced for given RPM.centrifugal weights moving to soon.no promises this is the problem something to consider though,very dated design.Was sometimes problem on ford essex v6 when dizzy got tired.
Gassing Station | Chimaera | Top of Page | What's New | My Stuff