FSE fuel regulator question please

[KKson]

Hi all, fitted the new FSE variable rate fuel regulator today and bloody hell what a difference it makes on mid gear pick up. It is way more responsive.

A couple of questions though....

I set it up to 40psi as per the Steve Heath bible. That was with engine off but flap given a poke (no smutty comments please), and all was well. When the engine actually ran in anger though with the vacuum connected, at tickover the fuel pressure was slightly lower at around 35psi and did even drop to 30 psi. A quick blip of the throttle and it jumped up to around 45psi. Is this correct?

When the engine was turned off the pressure sat around the 35psi and then slowly decayed to zero. I'm therefore assuming either I've a leaking injector or the regulator itself is not holding the pressure. I'm having a refurbished set of drop tight injectors fitted Thursday so that will count the leaking injectors out as the problem. Any other clues as to what may cause the loss of pressure when engine is off?

The car does start instantly when fired up though?

Cheers.

[mrzigazaga]

Hi Keith..Firstly that pressure is a bit too high for a 350i...You will be over fuelling big time..A good way to set it is to warm up the car to normal operating temp and clamp off the vacuum pipe that goes from the FPR to the plenum...This will simulate WOT, You need 36-38psi at WOT..(Wide Open Throttle)...On idle it should be around 23-25psi..The holding pressure will drop off slowly but from around 4-5psi..There is a holding pressure when running but don't worry about that at the minute..

Yes it will feel more responsive...When mine had the solid state on running at 36psi the car seemed to run a tad lean..This is why i went the adjustable FPR and changed to iridium plugs..They seem to be more efficient with the 98-99ron.

Once the fuel pressure is set do not be tempted to fiddle about with it if it has a gauge fitted...Sometimes the pressure will look too low but its not...If the pressure does start to fluctuate up and down then i found that to be a sign that the fuel pump is pants.

I noticed on a rolling road that 2psi increase gave 2 x bhp...Interesting....The pressure will also fluctuate up to what it is set to when under load and will rise when the throttle is blipped...Thats why its called a "Rising rate" fuel reg...
Hope this helps....Ziga

PS: If yours is starting on the button from cold then believe it or not there is something wrong with your CTS..Temperature sensor..Especially if you get any mis-fire..Hot or cold and at any rpm....I could be wrong but i think I'm not there for i am..

Edited by mrzigazaga on Sunday 7th June 21:04

[KKson]

Thanks Mark, I'll have a further play with it tomorrow night and drop it back down a little then. I changed the plugs as well yesterday and they were perfect colour wise. The car always starts first turn of the key but after a couple of minutes there is a slight unevenness in the running until it has warmed up a little more then all is well. I've got a couple of spare temperature sensors so I'll change one over to see if there is a difference.

Also bought and fitted the new boot seal as per your recommendation so thanks for that. Let's hope the boot stops stinking of exhaust fumes. Cheers.

[mrzigazaga]

No probs mate...The CTS might be fine..You can test them to see if they give any resistance by carefully removing the plug connector and testing the pins..If you get nothing then change it or check the wires to it...
A reminder of mine..

With it like this mine used to start on the button..But i had a intermittent mis-fire...Now the car is a pig to start but faultlessly pulls like a train when up to temp...If yours doesn't have a twitch or mis-fire then don't worry about it...Cheers...Ziga

[KKson]

mrzigazaga said:

.A good way to set it is to warm up the car to normal operating temp and clamp off the vacuum pipe that goes from the FPR to the plenum...This will simulate WOT, You need 36-38psi at WOT..(Wide Open Throttle)...On idle it should be around 23-25psi.

Mark, right I've double checked the Steve Heath bible and his settings are with the engine off, ignition on and flap tweaked to get the pump running. He recommends 39 to 40 psi. That's how it was set. At idle, pressure ran around 30psi but when I blocked the vacuum pipe pressure crept up to around 42psi. Likewise when I revved the nuts off it again peak pressure went up to around 42psi.

I've now run the engine up to temperature as you suggest, blocked the vacuum pipe and set the pressure at around 36 psi. At idle the pressure is now down to around 24 psi. With the vacuum pipe connected and a spirited rev the pressure peaks around the 36/37psi.

Is this typically what others are all running with a rising rate regulator? Just wondering why the two recommended pressure settings vary so much? Cheers.

[mrzigazaga]

Hi Keith...I haven't looked in the bible but know that it was written around Mr Heaths 400SE so it might be that...I know that the 390SE needs a tad more..Mine ran fine on 40+ but on the AFR at the rolling road done by AMD the fuel was around 14% which was too rich..Even though it gave me a couple more horses...There is talk that it can cause injectors to leak if the pressure is too high?..The only thing it caused on mine was leaky fuel rail even after i had it all overhauled...Another job i will have to do myself...Here was a post on it last year...I was excited to think i had a 3.9 but i think its a healthy 3.5..The numbers on the block say's it is although Tower view racing had done some engine work on it according to some paperwork i got with the car but unfortunately it only said.."Engine work = £2,500"...No breakdown of what though...Maybe cam???........Cheers...Ziga
https://www.google.co.uk/url?sa=t&rct=j&q=...

[mrzigazaga]

Bobby Shaftoe said:

An easy way to test the injectors for leaks, if you don't want to pull the injectors would be to run the car, switch it off then disconnect the injectors at the resistor pack and the cold start injector connector and then try and start the car again. If it trys to start again then suspect leaky injectors.

Or..You could clamp the fuel return on the FPR with engine running..Turn off straight after clamping and watch the holding pressure...If that drops which it shouldn't then you either have a leaking one-way check valve in the pump ...Or a leaking injector...On normal operation the fuel pressure would drop slowly after switching off the engine..Around 2-3psi in about 5 seconds..

If you have the correct pressure being maintained in the fuel rail at idle where the vacuum is at its highest then you should have a smooth and steady idle..900-950rpm is good for a 3.5 V8.

If an injector is leaking then the fuel pressure will noticeable jump about..Mine used to fluctuate between 10psi up or down...Not good...However the gauge was picking up the pump failing...So in effect an adjustable FPR with a gauge is a very good diagnostic tool..YES there are some shyte FSE types out there...The Malpassi are reputably good but can fail over time..I use a Sytec AFPR...There are multiple ways to test the diaphragms and injectors...But if you have no rough running at idle or intermittent mis-fires or rich running plugs..(Any 1 of the 8) then it could be the pump but i think you changed that didn't you a while back?...

Here is a good vid that explains the FPR in more detail...
https://www.youtube.com/watch?v=zTK9-DoGIVY

If there are no problems then a rolling road would be the best way to set up the FPR..You need the Air Fuel Ratio to be checked and most good rolling roads will do that.

Ziga

PS: I think you can also test the injectors by building up the pressure in the fuel rail..Clamp the return ..Trun off and then individually test the injectors with a PP9 battery..Im not sure of the pulse rate or volume but once you know that then you will see that amount drop off of the rail pressure...Anymore than that then it could indicate a leaking injector...I wouldn't do this until you know the flow rate and pulses per sec as you don't want to hold them open too long..1 second might be as much as 2psi???

Edited by mrzigazaga on Tuesday 9th June 10:10

[bradderztvr]

Hi Keith, I've bought an FSE regulator and presumed it would come with a gauge l, but it didn't (should have read the small print).
Seems the correct pressure is important, and the instructions on mine quote turning the adjuster a quarter of a turn either way depending what you want.
Think i best buy a gauge but some advise to not leave it fixed ? In other words set it up then remove it and refit plug ?

[KKson]

bradderztvr said:

Hi Keith, I've bought an FSE regulator and presumed it would come with a gauge l, but it didn't (should have read the small print).
Seems the correct pressure is important, and the instructions on mine quote turning the adjuster a quarter of a turn either way depending what you want.
Think i best buy a gauge but some advise to not leave it fixed ? In other words set it up then remove it and refit plug ?

Hi Roger, mine came with a gauge but I don't intend to leave the gauge permanently connected just in case, so if you want to borrow it, set yours up and drop it off at a later date (BBWF run over?) then no problems. I've dropped the pressure down to the figures Mark gave and it pulls like a train mid gear. A truly noticeable improvement. Only thing I did notice when set at the higher pressure was that when I floored it when cold (which I don't usually do to be honest) it stalled twice so I'm presuming I'd flooded it. The Wedge is in the garage tomorrow for all new fuel lines top to bottom, plus gearbox remote bushes plus new heater hoses while the plenum is off and fitting of newly refurbished injectors which after cleaning were giving up to 6% more fuel. I'll give it a blast tomorrow evening to see how it all behaves.

[bradderztvr]

That would be great, if I could borrow it to set up. I think you're doing the right thing getting the fuel lines in tip top condition, as I feel improving one area will find any weaknesses elsewhere. I replaced the fuel lines a few years ago, so shouldn't be too bad. To try and keep the injectors the clear, for many years now, I've put Strong injector cleaner in the fuel a couple of times a year, when the tank is low.
Be interested to hear how you get on.
Cheers Roger

[Rockettvr]

Hi
I changed to an fse one last year. I used to get a lot of hesitation and flat spots in the power delivery as the old original would allow the pressure to fluctuate. Now I've a much smoother power delivery and it pulls like a train in the mid range. Set it up as per zigs instructions above. Had no issues since.

[KKson]

Rockettvr said:

Hi
I changed to an fse one last year. I used to get a lot of hesitation and flat spots in the power delivery as the old original would allow the pressure to fluctuate. Now I've a much smoother power delivery and it pulls like a train in the mid range. Set it up as per zigs instructions above. Had no issues since.

Thanks for the that. It is now set up as per Marks instructions. Wedge is just having newly refurbished injectors plus full set of new fuel hoses fitted today so looking forward to have a run out tonight to see how it goes. The refurbed injectors as a minimum are giving 3% more fuel flow after cleaning and two of them now supposedly giving 6% more flow so can only help.

[mrzigazaga]

Always glad to help and only ever pass on what i have learnt from people who know their onions...I have been talking to Brother Chris as regards to injectors as i need to sort out my fuel rail as i stop a leak from one part and it springs up somewhere else...There are of course contributing factors to this as in the design of the earlier rail compared to the later type with the snap on connection for the FPR and the push fit injectors..

I do have a set of later injectors that might need a professional clean and test as they are push fit and are better in design so doing away with 8 of the hose clips..Also the old injectors have a micro head with what is described as a disc of rubber that the petrol gets sprayed over to create a spray pattern, This obviously is limited to spray pattern and volume whereas the later type have what is described as a micro shower head which gives a better and finer spray of fuel which will combust faster and more efficiently which is very beneficial.

Im going to see if i can utilise the later rail as the injectors are already on it and it would be easier to prepare that that fart about with my old one plus it doesn't have the hose joiners on the rail which is a pain to get hose on a bend to stop leaking!..I will need to get round the FPR fitting as i don't want to be buying a solid state FPR..They are not cheap and i much prefer the flexibility and diagnostic properties of the Adjustable FPR..I know that keeping the gauge on is not always a good idea but mine is a glycerin filled type and if it dries out then i will buy another as they are relatively cheap for good quality types..Plus i would rather have it on there than have to fonz about looking for it..Fitting it..Making sure its still working..Testing it and then doing what i needed to do with it..Which was using it to test something else...One thing i have learnt with TVR Wedges is that changing an indicator bulb CAN take a whole day..Bit like playing a game of KerPlunk..

Actually i could probably find a snap lock fitting to combat the FPR issue...Ponder..Ponder...

[mrzigazaga]

Hi Peeps...Just wondering if anyone has bought an FSE Power boost valve or kit that contained one of these that they are not using...That i could maybe purchase for some food vouchers or beer tokens..


Its proper name is a fuel rail adaptor..I can buy one if i have to as i would like to see what difference the later better flow injectors are like in comparison...Cheers...Ziga

[KKson]

mrzigazaga said:

Hi Peeps...Just wondering if anyone has bought an FSE Power boost valve or kit that contained one of these that they are not using...That i could maybe purchase for some food vouchers or beer tokens..


Its proper name is a fuel rail adaptor..I can buy one if i have to as i would like to see what difference the later better flow injectors are like in comparison...Cheers...Ziga

The FSE regulator I bought didn't have one of those connectors, just two fuel and one vacuum pipe standard push fit connectors.

Got the Wedge back tonight and it pulls like a proverbial Deltic. Brilliant mid gear pull. Only issue I noticed during a spirited drive was low oil pressure which appeared to fluctuate a fair bit. Always something to investigate. I've had this before and turned out to be crap blocking up the tube feeding the oil pressure transmitter. Hopefully it's the same issue.

[mrzigazaga]

Thanks Keith...I got the one from the garage that i have and luckily it doesn't have the snap on lock just a swaged end for the in/Out..I have a set of later injectors that are on it..Green top i think but a friend has a set of red top that i can have so i will save up and get them rebuild and re-hosed as they have the ferrel fitting instead of a clip.For now i will just sort the cracking hose on the bulkhead join of the fuel rail..I imagine the heat doesn't help as the hose is only 5 years old..

What oil do you have as that can give a different reading on oil pressure..Mine fluctuates from say 20-25 on town driving and then nearer 50 at 100 mph...Errr i mean kph...

[KKson]

I use Millers 20w/50. At tickover it's down to 10 /12psi, it usually runs around 20/25psi at town speeds then does usually jump up to 50psi at "enthusiastic speeds on the motorway etc". Tonight however according to the gauge it was 2/3psi at tickover and only 20psi during a hard fast run. Nothing has changed, the red oil pressure warning light did not come on so it could be crap in the oil way. It also had a new oil pressure relief valve in January.

When I bought the car it had done precious little mileage for over 5 years and I do occasionally get a lump of congealed black snot lifting out from the engine and doing some mischief. I'll remove the transmitter, give the orifice a good poke, stick a flexible tube on the outlet, run up the engine to pump some clean oil out then put it all back together again. Fingers crossed. I did the same back in January and it did the trick.

[mrzigazaga]

Mmmm..."Sludge"..Not good...I always use a flushing additive or oil during an oil change..Some people are against it but i don't want my engine sounding like an old tractor engine..My oil is still lovely and clear after it was changed..Roughly 3 months ago...Are all the connections good, Earths...etc