26 replies to this topic

[DaveyC]

I'm in the process of fitting a 255 fuel pump and I'm not sure which hose to use.

 

If I use the OEM hose then it doesn't seem tight on the new pump, I can easily rotate it and pull it off by hand.

Conversely, if I use the new hose then I have the same problem where it joins the fuel pump assembly at the top.

[pete-r]

It's a reducing hose so use the oem one.

[DaveyC]

I've put a hose clip on too which will hopefully stop it squirting off.

[Chris P Duck]

Try to blow down the output (marked F) connector on the top of the canister before you fit it. If you can blow into it something isn't airtight and you will get problems. Would have save me a lot of headaches!

[DaveyC]

It passed that test so it isn't completely hopeless, but the fuel pressure is going to be quite a lot more than I can recreate with my mouth. It idles fine at the moment. Will test it out on the road before I put the seat and stuff back in.

[Spitfire Engineering]

Try to blow down the output (marked F) connector on the top of the canister before you fit it. If you can blow into it something isn't airtight and you will get problems. Would have save me a lot of headaches!

 

Indeed

[kipper]

I've put a hose clip on too which will hopefully stop it squirting off.

 

I would certainly go along with this as I've learnt, to my great expense.

 

Thought that I would save myself some money and fit the pump myself. Followed the instructions to the latter. All seemed fine after some long periods of road testing.

 

Took the car up to Courteny's on Friday for the final mapping. On the last speed run on the Dyno, the convoluted pipe from the fuel pump to the upper part of the housing, blew off. Result is that now on pin 29 of the ECU we have a positive voltage, rather than a switch to earth which would activate the K16 relay which supplies power to the fuell pump and injectors. 

 

The result was another return trip from Courteneys with the car on my trailer, and it now looks like a new ECU, or at least having it checked out by a speclist company to see if has been damaged...And this is all because I did not put a worm drive clip on the fuel pipe on either end of the pump connections.

 

To be fair to John and Mark at Courteneys they made a sterling effort to track the problem, putting in some extra hours to fault find.

 

So make sure that a worm drive clip is installed at both ends of the uprated pump!

[stu8v]

I always use crimp on connections. Jubilee type clips arnt great imho and dont pull up even.

[Spitfire Engineering]

As mentioned several times before, it really isn't that simple to fit another pump into the unit as there are other considerations with the unit itself, hence all the issues seen on here before.

Not quite sure why there is such a great desire for Walbro units, outdated gear type pump, not very efficient and noisy.

 

 

 

[Spitfire Engineering]

 

I've put a hose clip on too which will hopefully stop it squirting off.

 

I would certainly go along with this as I've learnt, to my great expense.

 

Thought that I would save myself some money and fit the pump myself. Followed the instructions to the latter. All seemed fine after some long periods of road testing.

 

Took the car up to Courteny's on Friday for the final mapping. On the last speed run on the Dyno, the convoluted pipe from the fuel pump to the upper part of the housing, blew off. Result is that now on pin 29 of the ECU we have a positive voltage, rather than a switch to earth which would activate the K16 relay which supplies power to the fuell pump and injectors. 

 

The result was another return trip from Courteneys with the car on my trailer, and it now looks like a new ECU, or at least having it checked out by a speclist company to see if has been damaged...And this is all because I did not put a worm drive clip on the fuel pipe on either end of the pump connections.

 

To be fair to John and Mark at Courteneys they made a sterling effort to track the problem, putting in some extra hours to fault find.

 

So make sure that a worm drive clip is installed at both ends of the uprated pump!

 

 

It may be worth considering, IMHO of course, that if you are not sure of what you are doing the HP fuel system is the last thing you should be tampering with  

How did you come to the conclusion you needed a more powerful pump in the first place?

Why did you select a Walbro?

 

How did a drop in fuel pressure (which is all you would have seen) possibly damage the ECU??

 

[smiley]

 

Not quite sure why there is such a great desire for Walbro units, outdated gear type pump, not very efficient and noisy.

 

 

 

 

A. It's on the CS SC conversion website as an optional part. B. It has been confirmed to fit our pump housing unit. C. It has been confirmed to been used succesfully without blowing up the car.

 

 

You are the first hint of using anything alternative in the 15 years the car has been out there.

Edited by smiley, 12 July 2015 - 08:41 AM.

[kipper]

 

 

I've put a hose clip on too which will hopefully stop it squirting off.

 

I would certainly go along with this as I've learnt, to my great expense.

 

Thought that I would save myself some money and fit the pump myself. Followed the instructions to the latter. All seemed fine after some long periods of road testing.

 

Took the car up to Courteny's on Friday for the final mapping. On the last speed run on the Dyno, the convoluted pipe from the fuel pump to the upper part of the housing, blew off. Result is that now on pin 29 of the ECU we have a positive voltage, rather than a switch to earth which would activate the K16 relay which supplies power to the fuell pump and injectors. 

 

The result was another return trip from Courteneys with the car on my trailer, and it now looks like a new ECU, or at least having it checked out by a speclist company to see if has been damaged...And this is all because I did not put a worm drive clip on the fuel pipe on either end of the pump connections.

 

To be fair to John and Mark at Courteneys they made a sterling effort to track the problem, putting in some extra hours to fault find.

 

So make sure that a worm drive clip is installed at both ends of the uprated pump!

 

 

It may be worth considering, IMHO of course, that if you are not sure of what you are doing the HP fuel system is the last thing you should be tampering with  

How did you come to the conclusion you needed a more powerful pump in the first place?

Why did you select a Walbro?

 

How did a drop in fuel pressure (which is all you would have seen) possibly damage the ECU??

 

On my last vist to Courtenys, to fit a modified K06 turbo, and 3" exhaust, testing on the dyno showed a 1 bar drop in fuel pressure at full power runs. So John/Mark's suggested in fitting the 225. Which I did. Noise wise there was no detectable difference over the OEM pump.

 

The the pumps internal supply pipe, blew off on the final mapping run on the Dyno. TRhe fuel pump was rememved and the convoluted pipe reconnected and secured with clips.

The car could not be started unless the activation coil of relay K16, was bypassed and connected directly to an earth. Currently there is a 12 volt+ existing on pin 62 of the ECU, where there should be a connection to earth, activated by the ECU.

There exists a possibiulity that there is a fault else where, so I will have to, remove the ECU and test whetere 12 volts still exists on the coil part of the relay. 

 

So the conclusion was that under full power with the fuel pipe blowing off there was a current surge that damaged the ECU.

[Spitfire Engineering]

 

 

 

I've put a hose clip on too which will hopefully stop it squirting off.

 

I would certainly go along with this as I've learnt, to my great expense.

 

Thought that I would save myself some money and fit the pump myself. Followed the instructions to the latter. All seemed fine after some long periods of road testing.

 

Took the car up to Courteny's on Friday for the final mapping. On the last speed run on the Dyno, the convoluted pipe from the fuel pump to the upper part of the housing, blew off. Result is that now on pin 29 of the ECU we have a positive voltage, rather than a switch to earth which would activate the K16 relay which supplies power to the fuell pump and injectors. 

 

The result was another return trip from Courteneys with the car on my trailer, and it now looks like a new ECU, or at least having it checked out by a speclist company to see if has been damaged...And this is all because I did not put a worm drive clip on the fuel pipe on either end of the pump connections.

 

To be fair to John and Mark at Courteneys they made a sterling effort to track the problem, putting in some extra hours to fault find.

 

So make sure that a worm drive clip is installed at both ends of the uprated pump!

 

 

It may be worth considering, IMHO of course, that if you are not sure of what you are doing the HP fuel system is the last thing you should be tampering with  

How did you come to the conclusion you needed a more powerful pump in the first place?

Why did you select a Walbro?

 

How did a drop in fuel pressure (which is all you would have seen) possibly damage the ECU??

 

On my last vist to Courtenys, to fit a modified K06 turbo, and 3" exhaust, testing on the dyno showed a 1 bar drop in fuel pressure at full power runs. So John/Mark's suggested in fitting the 225. Which I did. Noise wise there was no detectable difference over the OEM pump.

 

The the pumps internal supply pipe, blew off on the final mapping run on the Dyno. TRhe fuel pump was rememved and the convoluted pipe reconnected and secured with clips.

The car could not be started unless the activation coil of relay K16, was bypassed and connected directly to an earth. Currently there is a 12 volt+ existing on pin 62 of the ECU, where there should be a connection to earth, activated by the ECU.

There exists a possibiulity that there is a fault else where, so I will have to, remove the ECU and test whetere 12 volts still exists on the coil part of the relay. 

 

So the conclusion was that under full power with the fuel pipe blowing off there was a current surge that damaged the ECU.

 

OK, I think you need to look elswhere for the problem, sudden failure of this pipe would result in a reduction of current from about 11A down to 6A which is pretty minimal, (about half the load difference of turning the pump on and off in the first (or flashing your lights) and without the spike, as the pump is still pumping fuel and the mass needs to accelerate to the new fuel flow speed.

 

Did you check for a back pressure in the return pipe? this is one of the issues of not modifing the unit to match the new pumps output specification.

 

Gaz

 

[Chris P Duck]

Having experienced both the Walbro and the TRE that Gaz fits in my car I can honestly say the TRE is MUCH quieter.

[kipper]

 

 

 

 

I've put a hose clip on too which will hopefully stop it squirting off.

 

I would certainly go along with this as I've learnt, to my great expense.

 

Thought that I would save myself some money and fit the pump myself. Followed the instructions to the latter. All seemed fine after some long periods of road testing.

 

Took the car up to Courteny's on Friday for the final mapping. On the last speed run on the Dyno, the convoluted pipe from the fuel pump to the upper part of the housing, blew off. Result is that now on pin 29 of the ECU we have a positive voltage, rather than a switch to earth which would activate the K16 relay which supplies power to the fuell pump and injectors. 

 

The result was another return trip from Courteneys with the car on my trailer, and it now looks like a new ECU, or at least having it checked out by a speclist company to see if has been damaged...And this is all because I did not put a worm drive clip on the fuel pipe on either end of the pump connections.

 

To be fair to John and Mark at Courteneys they made a sterling effort to track the problem, putting in some extra hours to fault find.

 

So make sure that a worm drive clip is installed at both ends of the uprated pump!

 

 

It may be worth considering, IMHO of course, that if you are not sure of what you are doing the HP fuel system is the last thing you should be tampering with  

How did you come to the conclusion you needed a more powerful pump in the first place?

Why did you select a Walbro?

 

How did a drop in fuel pressure (which is all you would have seen) possibly damage the ECU??

 

On my last vist to Courtenys, to fit a modified K06 turbo, and 3" exhaust, testing on the dyno showed a 1 bar drop in fuel pressure at full power runs. So John/Mark's suggested in fitting the 225. Which I did. Noise wise there was no detectable difference over the OEM pump.

 

The the pumps internal supply pipe, blew off on the final mapping run on the Dyno. TRhe fuel pump was rememved and the convoluted pipe reconnected and secured with clips.

The car could not be started unless the activation coil of relay K16, was bypassed and connected directly to an earth. Currently there is a 12 volt+ existing on pin 62 of the ECU, where there should be a connection to earth, activated by the ECU.

There exists a possibiulity that there is a fault else where, so I will have to, remove the ECU and test whetere 12 volts still exists on the coil part of the relay. 

 

So the conclusion was that under full power with the fuel pipe blowing off there was a current surge that damaged the ECU.

 

OK, I think you need to look elswhere for the problem, sudden failure of this pipe would result in a reduction of current from about 11A down to 6A which is pretty minimal, (about half the load difference of turning the pump on and off in the first (or flashing your lights) and without the spike, as the pump is still pumping fuel and the mass needs to accelerate to the new fuel flow speed.

 

Did you check for a back pressure in the return pipe? this is one of the issues of not modifing the unit to match the new pumps output specification.

 

Gaz

 

 

 

Thanks for the suggestions Gaz. I'm not too sure whether John or Mark checked the back pressure in the return pipe. It would be great if there might be another cause other than a damaged ECU.

The problem is getting the K16 relay to trigger. Everything works if you connect pin 4 to earth and the relay engauges. However, the ECU then throws up an error code. As part of the fault finding I've got to check the continuity of the white/violet cable from pin 4 on the relay to pin 62 on the ECU. I also think that a sudden loss of pump capacity,  and the subsequent sharp drop in the amperage demand from the pump should not have damaged the ECU...but then I've got no experience in this!  

[DaveyC]

Pump seems to work fine. As for the noise - yes, it is noisy for the 2 seconds that the pump primes when the key is turned but I can't hear it when I'm driving so that isn't a real issue.

 

What's all this about modifying the return pipe? I've not seen this mentioned anywhere on any of the guides or tutorials.

[Spitfire Engineering]

Pump seems to work fine. As for the noise - yes, it is noisy for the 2 seconds that the pump primes when the key is turned but I can't hear it when I'm driving so that isn't a real issue.

 

What's all this about modifying the return pipe? I've not seen this mentioned anywhere on any of the guides or tutorials.

 

You probably have seen the result mentioned but just not realised. There are a few threads on this forum regarding fuel starvation on track after an uprated pump (Walbro 255) was fitted, the opposite to what you would expect of course. This is the most likely result of not modifying the unit to the new pump.

It's part of the work carried out when we fit new pumps, along with an uprated wiring harness etc, etc.

 

[DaveyC]

 

Pump seems to work fine. As for the noise - yes, it is noisy for the 2 seconds that the pump primes when the key is turned but I can't hear it when I'm driving so that isn't a real issue.

 

What's all this about modifying the return pipe? I've not seen this mentioned anywhere on any of the guides or tutorials.

 

You probably have seen the result mentioned but just not realised. There are a few threads on this forum regarding fuel starvation on track after an uprated pump (Walbro 255) was fitted, the opposite to what you would expect of course. This is the most likely result of not modifying the unit to the new pump.

It's part of the work carried out when we fit new pumps, along with an uprated wiring harness etc, etc.

 

 

 

Hmm. Any threads containing the words Walbro and Starvation seem to be offering the Walbro as a solution to possible starvation with the OEM pump or talking about starvation from the un-baffled fuel tank.

 

Scratch that. I have managed to find a few threads where you mention this to people who are thinking of buying a Walbro, but can't find any reports from users actually fitting one.

 

Has anyone else on here modified the return line at all when fitting a different pump?

Edited by DaveyC, 13 July 2015 - 12:17 PM.

[Spitfire Engineering]

 

 

Pump seems to work fine. As for the noise - yes, it is noisy for the 2 seconds that the pump primes when the key is turned but I can't hear it when I'm driving so that isn't a real issue.

 

What's all this about modifying the return pipe? I've not seen this mentioned anywhere on any of the guides or tutorials.

 

You probably have seen the result mentioned but just not realised. There are a few threads on this forum regarding fuel starvation on track after an uprated pump (Walbro 255) was fitted, the opposite to what you would expect of course. This is the most likely result of not modifying the unit to the new pump.

It's part of the work carried out when we fit new pumps, along with an uprated wiring harness etc, etc.

 

 

 

Hmm. Any threads containing the words Walbro and Starvation seem to be offering the Walbro as a solution to possible starvation with the OEM pump or talking about starvation from the un-baffled fuel tank.

 

Scratch that. I have managed to find a few threads where you mention this to people who are thinking of buying a Walbro, but can't find any reports from users actually fitting one.

 

Has anyone else on here modified the return line at all when fitting a different pump?

 

 

Well if the O.E pump cannot make the new required flow then you would expect to see starvation issues at higher power settings, an uprated pump would be required, 

The problem with starvation after the pump has been uprated and not always at high power settings, usually long left handers is a canister refill problem. 

99% sure it is on this forum as only the S2 and VX use this pump module.

All the Delphi pumps we modify have this work done, about 150+ at a guess including most of Bernards Audi conversions where it was a standard fit, quite a few on here as well over the years at least 20.

 

[DaveyC]

This post keeps cropping up in forum searches:

 

 

Spitfire Engineering, on 12 Apr 2013 - 12:22 AM, said:

Regarding your setup, is the installation noisy? If so it allows a possibility which may help and save you a lot of money. Basically the unit has an eductor which is tuned to the output (well more accurately the return) pressure. If you just fit the Walbro without adjusting this it usually results in high pressure return fuel hitting the lid of the pump unit and flying out sideways, outside of the pump canister, this fuel normally gently flows over the top of the standpipe and into the can. What this means in reality is the return fuel which should not only be returned to the canister but also suck in fresh tank fuel via the eductor principle as well, is mostly sprayed back into the tank reducing the fuel in the canister for the next corner. We have sold loads of S2/VX units to Bernard for the Audi Elise conversions all without issue and they make similar outputs. If you are going to hard track the car at tracks with long left handers then a swirlpot or trapped tank is needed, the advantage of a trapped tank is that it keeps a single in tank pump, personally I am not a fan of several feet of HP fuel hose and several components in the engine bay.

 

 

How would I go about modifying the unit to prevent this?