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Paddock rumor is Renault are having trouble acquiring insurance for KMag's 1.5 diesel Clio and he refuses to drive for them until they pay for his use of a company car.
Less widespread rumor is his company car is leftover espace F1
Drove the Integra to work today. First time I've driven it more than a mile in almost a year. Feels good man. Oil hasn't been changed in it since 2012. Still have about 2000 miles to go. :-o
To set it up when the car gets to operating temperature and it's hot outside my fuel pressure drops. 20 min drive home from work base fuel pressure drops from 43psi to 33psi. This doesn't happen when it's cold out. It drops a few psi once it's warmed up but typically 2 to 3, which seems to be pretty standard. I can confirm it is not the sensor I'm using. The gauge on the rail is showing the same pressure as the sensor (both at start up when it's 43psi and when it warms up and it's 10+ psi lower). The drop happens over a gradual period of time.
The interesting thing is when I go into positive manifold pressure my fuel pressure is right where it should be. For example on the way home today at 10lbs of boost my fuel pressure was 53 psi. As soon as I let off the gas fuel pressure drops back to where it was, 33 psi this time. Using a Aeromotive fire wall mount fpr and I've already tried a new diaphragm. No fuel leaks anywhere. Don't see it and don't smell it. I replaced the fpr vac line and no difference.
Why would the fuel pressure remain static? Wouldn't pressure be dependent on the load (mass flow) of the pump against the the resistance in the system (assuming constant volume, with the exception of the injectors opening/closing).
I feel like it should be moving...Unless I'm wrong?
The inner mechanism usually consists of a sealed diaphram chamber, a spring, a diaphram, bypass valve and a manifold pressure reference port. The valve is connected to the diaphram and the spring pushes against the diaphram from the manifold pressure side. The spring pressure determines the static fuel pressure. If there is vacuum on the port, say at idle, this reduces the effective spring pressure acting on the diaphram and reduces the fuel pressure under vacuum conditions. If there is pressure on the port, such as under boost, this effectively increases the spring pressure, thus fuel pressure.
I mean... this sounds like a dynamic system to me...
Why would the fuel pressure remain static? Wouldn't pressure be dependent on the load (mass flow) of the pump against the the resistance in the system (assuming constant volume, with the exception of the injectors opening/closing).
I feel like it should be moving...Unless I'm wrong?
Return from the rail? or you running return-less?
The fuel line runs: tank---filter---rail---fpr---return to tank
The fpr controls the fuel flow based on manifold vacuum which is more or less constant (at idle). This issue affects part throttle operation considerably. My AFR was running 14.7-15.0 at idle this morning from the time I left until the time I arrived at work and even idled in the parking lot for a bit. My trip home idle AFR started at 14.7-15.0 but by the time I got home it was 16.0+. It also affects part throttle cruise, was stumbling and breaking up at part throttle cruise, AFR into the high 15s at times. This only seems to happen when it gets hot out. It might happen in the winter if I let the car heatsoak long enough but so far I have not had it happen.
I could be wrong (probably am wrong), but it sounds like your base/static pressure is too low. I wouldn't touch it without consulting your tuner, as everything he's done is made under an assumption of base pressure.
But your hot vs cold idle differences make sense to me. More fuel on cold start up = lower AFR. Hot start/idle = less fuel = higher AFR.
04-26-2016, 10:33 AM
Re: The Official Formula 1 2016 Season Thread
