Bosch 040 Intank Pump Feedback?walbro Going!

[LUMO]

Once again it really depends on what you want to do with it. At the power level you are looking for, I'd be fitting one.

Particularly if you are looking to run a decent time on the quarter mile and thus low fuel level in the tank.

thanks for your advice Raphoon appreciate it

Pete

[useless]

Well the walbro is coming out tommorow Provided I get a munte.Cant wait to get rid of the thing. if you guys are happy then that's all that counts.Me I want it to work that's all.Will post up if the issues are fixed soon. I want to race the wagon soon.

Edited 09/06/07 02:43 PM by useless

[tquarrell]

From my experience with my stock fuel pump, I'd replace it at 250+. With no changes to the tune or anything, modifying the relief valve on the stock pump resulted in an increase from 236 to 270 rwkw. Replacing it wit a walbro helped further. As the guys have said, it is all dependant on your afr's. The pump's do deteriorate with time and I think this is the main reason for the difference in my case.

As for the low fuel level problems, I believe alot of guys are fitting surge tanks to resolve this. The rationale is that the swirl pots pickup is compromised with the required flow of a hipo engine and low available fuel, hence having a reserve available for the engine to draw on before the tank eliminates the problem. A simple alternative is to keep more than a 1/4 of a tank of fuel in car (easier said than done I know).

[useless]

From my experience with my stock fuel pump, I'd replace it at 250+. With no changes to the tune or anything, modifying the relief valve on the stock pump resulted in an increase from 236 to 270 rwkw. Replacing it wit a walbro helped further. As the guys have said, it is all dependant on your afr's. The pump's do deteriorate with time and I think this is the main reason for the difference in my case.

As for the low fuel level problems, I believe alot of guys are fitting surge tanks to resolve this. The rationale is that the swirl pots pickup is compromised with the required flow of a hipo engine and low available fuel, hence having a reserve available for the engine to draw on before the tank eliminates the problem. A simple alternative is to keep more than a 1/4 of a tank of fuel in car (easier said than done I know).

Thanks for the feedback..it is good to know these experiences. This morning I jacked up the car and decided to try the stock pump in the car.The tank is very low in fuel. The first thing I noticed was that the fuel pressure gauge on my sard regulator read the same as the walbro while running .One big difference was that when I turned the key off the pressure drop was only 1 psi. With the walbro it dropped by 10 psi which indicates a bad check valve design . As it was cold it spluttered slightly once. When warm the car went good.

The noticeable differences are that before with the walbro part throttle had little response to the accelerator and needed more throttle to make the car go. So far with the stock pump part throttle response has returned with drivability in this area.It is a welcome friend.

The second thing I have noticed is that full throttle the car doesnt feel as strong.The response feels less savage but much smoother. I cant tell if it is faster or slower but smooth power is normally a faster car. I will be timing the car and getting on a dyno to see if the swap back to standard pump has robbed me of any power. At 170rwkws in na form from the au six I cant complain..the pump should be good for this. I must admit that the throttle response may be because of the low fuel.Even standard pumped cars feel a little doughy with lower fuel so the next week of driving will reveal the results to me.

If the problems persist into the next week then It must be the injectors or not enough enrichment off idle to compensate for my head work and mods. Apart from that new leads and plugs will be going in next week to discount ignition issues.

Edited 10/06/07 12:18 AM by useless

[useless]

Since last I have been fititng the bosch 040 to my swirlpot assembly. It is now in with quite a few modifications to the assembly to make it fit.It took around 3 hours just to fit it to the assembly which is on my desk at home...the standard pump is still in the car as I have a second spare that I am playing with right now..

[useless]

Guys I never put the bosch in until today.I found the walbro only fed constant fuel for 12 seconds then flow fluctuated badly into a container . The relay was removed and constant power fed to the pump for testing.

With the bosch the fuel just keeps flowing. The car is driving very good.. I have had very poor off idle acceleration and misfiring for around the past 4 months.As soon as I touch the accelerator now the car responds to even a light tap of the pedal.I am very very relieved after all this time.

I

[turbotrana]

Can you post up good close up pictures of your "Walbro" pump to see if its a genuine one or not. Who did you buy this pump from in the first place. Its good to see you found the problem but lets try and find out more about this pump.

[useless]

Can you post up good close up pictures of your "Walbro" pump to see if its a genuine one or not. Who did you buy this pump from in the first place. Its good to see you found the problem but lets try and find out more about this pump.

I wont say who sold it to me as I dont want to start trouble. However I will take a few shots tommorow if you want.