Low fuel pressure at idle

[Spirry]

Originally Posted by Enki Yes it would, it would delay/accelerate it slightly depending on which direction it was advancing/retarding. There are three lobes which probably don't quite line up with fuel injection events, so if the cam is on the trailing edge of applying fuel pressure when the injector opens AND the cam is retarding due to VVT falling off then that is pretty much the worst case scenario.

Thanks! Running two more psi boost on stock FP internals now.

[Enki]

What did you ditch VVT and gain fuel headroom?

LMAO

[Spirry]

Originally Posted by Enki What did you ditch VVT and gain fuel headroom? LMAO

Yup.

[Enki]

Should post a thread; this *seems* like a decent way to buy some headroom.

[event]

Originally Posted by Enki Should post a thread; this *seems* like a decent way to buy some headroom.

I'm sure as hell interested. VVT is something I haven't touched. It seems like voodoo to me right now. Need more quality threads on the subject! Nobody ever talks about it except when they have to replace the tensioner.

[Decepticon]

OP did ur check engine light code p0303 go away when u installed the new relief valve? I'm getting the same exact issue.

[daafisch]

event I'm having the same exact issues you're describing. 150-250 idle pressure, noisy spill valve, normal pressure at cruise and then triple digits under higher load, except autotechs look fine.

Did the relief valve cure all of these issues? If so where did you get another OEM relief valve?

[smoogs12]

daafisch As far as where to get a replacement RV, I believe that I had read in a thread that it was now available separate from the fuel rail at onlinemazda parts. Give them a call.

[event]

Originally Posted by daafisch event I'm having the same exact issues you're describing. 150-250 idle pressure, noisy spill valve, normal pressure at cruise and then triple digits under higher load, except autotechs look fine. Did the relief valve cure all of these issues? If so where did you get another OEM relief valve?

Check the fuel pressure with the car hot and off, it should rise to 1600+ psi. If it doesn't replace the RV. Look at the 2011+ CX-7 for the rail valve. You can get it at mazda dealerships.

[daafisch]

Pick one up from SPEED6 KILLAH last night and installed it. Seems to have fixed the problem. No more ticking and pressure is back to normal.

[SPEED6 KILLAH]

Originally Posted by daafisch Pick one up from SPEED6 KILLAH last night and installed it. Seems to have fixed the problem. No more ticking and pressure is back to normal.

that good to hear it fix. What is the pressure reading now?
I anyone need one just PM me future..

[daafisch]

400+ at idle and seems to be holding at WOT.

Also, the spill valve isn't making anymore noise.

400+ at idle and seems to be holding at WOT.

Also, the spill valve isn't making anymore noise.

[Jackis]

Looks like I shoud revive this thread now...
A year ago I have installed KMD internals and have changed my ITFP body (so I believe it should be clean).

Several days ago I started noticing sudden drops when accelerating between 3-4K rpm. Unfortunately, my DH is not with me at the moment. I decided to wait a little bit and see if it'd happen again.

Last friday my car just didn't start at all. I tried this and that, touched and retightened all the connections as a dumb and so on, but nothing helped. Also noticed that when I turned the key on with the hood opened, I can here some very-very slight clicking noise (not noticeable with the hood closed). Looks like it is a spill valve, and I hope that very low clicking noise is acceptable?

I waited for my friend with my DH, we connected it and I saw Fuelrail Pressure is ONLY 40kPa (6 psi only), while it should be around 400!!!

Ok, I decided that either my HPFP internals died or my ITFP died or has wiring problems. Next morning I tried to start - fail. I got to my ITFP conenctions under back seat, removed PLENTY of debris and dust from it - and whoah! It started normally with correct fuel pressure numbers.

I decided that it was electrical issue, also dureing a week-end there were no pressure drops at WOT also, car went fine as it should. But yesterday morning I again tried to WOT - and it stumbled several times at 3.5-4K range in 5th and 6th gear (3rd looked fine tho).
Yesterday evening on a way home there were huge tropical rain here, almost an hour. I didn't WOT because I didn't want water droplets hitting my MAF... But it looked fine and stable with fuel pressure on idle and cruise.

Today morning it just didn't start again, and nothing helped. And I again have no DHs with me, but I bet it is the same unreal FuelRail pressure before the start.

This issue now is annoying for me, because I really have my BT stuff ready to set up, and because I am not familiar so far with all those spill valves/ratainer valves/..., I want to ask you for the advice and directions what to do.

Thank you for your time!

[Jackis]

If someone ever interested, I have localized my issue above.

KMD piston was jammed in the upper point and never moved on the internal. A lots of scratches also.

Don't know what was the reason - maybe the fuel, which was in my tank for 2 months while I was repairing my car. May be. I am pretty sure installation was fine - I did all to the T. The whole last year (15K) before failure is gave me solid pressure.

I don't want to blame KMD, it can be the fuel issue (the dirt from the tank, for example, I donno), but the fact is...

So far put the stock internals back.