Balancing throttle bodies

[spitfire4v8]

You *may* have a thermal barrier leak anyway, but your symptoms don't suggest it, it would have to be a massive leak on both banks to outstrip the ability of the ecu to trim 37 percent of extra airflow and still be running weak.

To check fuel pressure you need to Tee a pressure gauge into the high pressure feed pipe (ie NOT the one coming off the back of the regulator)

It's a bosch regulator and you'd be most unlucky if it was failing, but don't discount it.

After that you're pretty much on your own, that's about as much diagnosis as can be done without seeing the car.

[Jooles81]

OK, thanks a lot for the feedback, again.

I understand what happens if the pressure is low and I'll have a look at that. I'll make you a feedback.

Julien

[Jooles81]

Hello!

I'm undigging this thread a bit because it appears that no-one here has the necessary fitting to plug a fuel pressure manometer...

Can you please tell me what is the standard of the fitting on the hose feeding the fuel rail? I've read 1/2 bsp somewhere but I'd like to be sure...

Thanks in advance!

Julien

[Jooles81]

Hello,

Anyone could tell me how to check the fuel pressure on those things? I've bought some fittings, but they are apparently not the right one. Is the feeding of the rail the right place? If so, could someone tell me the standard or point à manometer kit that works?

Thanks in advanc!

Julien

[Jooles81]

Hello,

so, for the record, the standard of the fuel hose connector feeding the injection rail is 1/4 BSP.

So now, find a fuel manometer...

Julien

[Jooles81]

Hello,

I've finally had the fuel pressure checked. It comes at 3.7 bars. That's not a lot over normal, so should not generate those problems according to my mechanic. There is huge crack in one manifold. He'll weld it and check the injectors and we'll see what happen...

Julien

[ukkid35]

spitfire4v8 said:

C


Try also clamping off the small pipe that goes to the airbox oil catch tank (it's supposed to have a restrictor in it, but people replace the hose not realising it's supposed to be restricted and end up with that pipe as a source of a big air leak.)

If you could detail the dimensions of the restrictor (which is new to me) I'd be very grateful indeed

[spitfire4v8]

It's tiny .. something like 1mm drill bit ?
To be honest, there's many a time I've just blocked that pipe up. It even says to block it up during engine setting up, then unblock it afterwards .. what?? !! ??

[Jooles81]

Hello!

I'm slowly going forward... One manifold was cracked and has been welded. Today I had the car on the dyno with wide bands on both banks because one lambda was showing constantly lean. It appears that one bank is in dead constantly lean, whatever you do. So lean the wide band do not show anything. What could be the causes? My mechanics says it can be a blocked injector, or maybe a cylinder not igniting. Any other cause?

Thanks

Julien