Hi guys.
Just driven back from a car show and the car started running like a bag of sh@te. Feels like it’s being starved of fuel I.e pressing the throttle and the engine falters ease off and away we go. Got to the point when nearly home then engine stalled it restarts no problem and then away we go again. New pump and filter fitted a couple of months ago. Advice as always greatly appreciated.
Rob.

 

Do the v12s have a port for a fuel pressure gauge?

 

Quote:

New pump and filter fitted a couple of months ago.

Pull the fuel filter and empty the contents into a clean container. What you see, or don't see, will dictate your next steps.

Quote:

Do the v12s have a port for a fuel pressure gauge?

Nope!

Cheers
DD

 

I’m sure one can be fitted to the tail. I don’t have one at the moment though.

 

Hi guys. Fuel filter is new replaced only a few weeks ago. I did cut the old one open to have a look and it was very clean inside. Swirl tank is all clean as well again with a new filter in place. I suppose the new fuel pump might be at fault? I did replace the both fuel pre regulators on the fuel rail when replacing the pump. Any ideas? Are there any electrical issues that might cause these symptoms?
Rob

 

Hi guys.
I just went and started the car which was fine and fired right up. The engine runs really smoothly when cold and even smoother when warmed up. I did however notice when revving the engine by opening the throttle quickly I did get a back fire. No backfire when opening the throttle gradually. I haven't taken the car out on the road yet this was only while sitting in the garage. Ideas please.
Rob.

 

How is the distributor and associated wiring? The lack of power could be Marelli failure, and the backfire could be timing. If the fuel system is all good then we must look elsewhere!

 

Assuming it was fine driving to the car show, trying to think what could go wrong to cause your issue. Wild guess, check that all your throttle linkage bushings are in place and in good condition. If one or more are missing or really loose, it can cause a mismatch between the throttle opening, ECU fueling signal and the spark signal, and perhaps that might lead to a backfire. Next, I would test the throttle potentiometer.

 

Is the fuel tank breathing properly? Did you open the fuel cap after some driving?

 

Tank breathing all ok plus a small hole drilled in cap to make sure. I did think about the TPS as mine is still the original. I think I will put the old fuel pump back on the car as that was working fine just a bit noisy and see it that makes any difference. Both fuel pressure regulators were renewed but again I could refit the old ones as they were ok. Jobs for the weekend I think. I want to get it right as I have another car show booked the end of the month.
Rob.