Remap if I change to a Bosch 004 pump??

[philiwily]

Not supporting enough fuel to the injectors isn\'t fuel cut, and if your going to have more hp after changing your pump it would only be because your previous pump was providing insufficient flow to start with which would warrant a check of the map.
I\'ve done quite a bit of mapping but if Blitzboy, who has a lot more experience of mapping, comes along and says he has experienced something I would take it on board.

[Benny]

if you have a fuel pump with  insufficient flow you could suffer from fuel cut at higher rev\'s, that\'s what I was trying to say.

still, mapping after a fuel pump change is BULL:censored::censored::censored::censored:.
the injectors won\'t inject more fuel because of the stronger fuel pump...

[BlitzBoy]

Depends if you have an adjustable FPR or not Benny, if you need a remap or not, if you are using the stock non adjustable fpr then the better fuel pump WILL give you increased fuel pressure and you WILL be running richer.
But changing any part of the fuel system I would advise anyone to get the AFRs checked on the rolling road just in case, just to be safe.

[Benny]

oh man come on... why should the fuel pressure increase if you leave the stock fpr in it?

the fpr regulates the pressure... like it\'s name already says it, so why should the pressure go up?? the fpr doesn\'t break, give up, or what ever because of the stronger fuel pump..!?

[davehg]

Surely it all boils down to do you want to chance blowing it up and the cost of an engine rebuild over the small cost of a tweak and remap.... Too many people try to cut corners these days... Why even change the pump if your not going to remap??

[BlitzBoy]

oh man come on... why should the fuel pressure increase if you leave the stock fpr in it?

the fpr regulates the pressure... like it\'s name already says it, so why should the pressure go up?? the fpr doesn\'t break, give up, or what ever because of the stronger fuel pump..!?

oh man do some more reading, or is it just stuff you read off the internet!!!

the stock FPR on system is designed with the specific pump and flow rate in mind dude!!!!!!!! when putting a higher flow pump which flows more the fuel pressure goes up , as you have not changed the diagprham spring pressure its fixed!

By your logic Man , there is no point in buying aftermarket adjustable FPRs LOL

Also seeing as I have mapped over 100 of these bloody RX7s and know what happens in reality

Also the stock FPR and FPD will fail over time if you put too big a pump on them

[BlitzBoy]

So what happens with a stock fpr with fixed preload on the spring and a bigger pump it cannot flow enough excess fuel back to the tank therefore fuel pressure goes up, if it was adjustable then you can slacken off the preload spring to maintain correct base pressure and the excess fuel can go back to tank

[Grant Monkhouse]

Any change to the fuel system if DIY is worthy of a quick check over by a person that maps rotaries. A bit of cash is better than a rebuild, plus you can always get more boost in there:) which is always a bonus.

[BlitzBoy]

If Benny still is not convinced, here some info from AEM themselves, explaining it in different words

"Other "universal" regulators incorporate a fixed discharge orifice that does not allow users to control fuel flow if the fuel pump is different than stock. In cases where a larger fuel pump is used for high-horsepower applications, a regulator that has too small of a discharge orifice will not allow fuel to be bypassed when the vacuum in the top chamber is increased. This causes a momentary rich condition that, depending on the severity, can cause an engine to stumble or stall. On street cars, this condition could degrade catalytic converter performance. On the flip side, if the discharge orifice is too large it can make controlling fuel pressure within the regulator difficult since small changes to the setscrew can affect large changes in fuel pressure. A too-large orifice can also cause fuel pressure to "hunt" during fluctuating throttle conditions, which can cause a momentary lean condition. That could spell disaster in the form of detonation, which is a turbocharged car\'s worst enemy."