View Full Version : Fuel Rail Monitor Failure

04-10-2008, 07:32 PM
Cobra drivers,

I have an 03 cobra with 2.6 KB, 60 lb injectors, GT pumps. Since I've had the KB and GT pumps put it, the fuel rail sensor/monitor has failed to the open position two times in less than 300 miles, thus flooding the car. They only way to start the car afterwards is to replace the spark plugs and monitor. I'm tired of taking it to the shop and am looking a way to prevent it in the future...anyone have any ideas?


04-10-2008, 10:45 PM
kenne belle makes a restrictor plate for the frps which prevents spikes in fp that blow them out.

not sure if you can get them anymore but do a search for kb restrictor plate

04-10-2008, 11:16 PM
After the first time it happened the shop put the KB restrictor in. Not sure if anyone else has had this problem. I'm tired of taking it to the shop though...

04-10-2008, 11:22 PM
thats the first time ive heard of it blowing an frps with a restrictor in it. There must be a huge spike in fuel pressure for some reason because that hole is small and to force enough pressure through that hole at one time would take alot of fuel pressure. Your 100% sure its the frps thats bad? Im assuming its throwing a code or something along those lines?

04-10-2008, 11:30 PM
No code with it. The car just won't start and it smells like fuel when I try to start it. Both times the shop guy said the sensor was blown. I'm doing some more looking on line but am not finding much. Prior to putting the GT pumps in, the car had the KB BAP which is still hooked up as far as I know. Not sure if the after market rails are big enough or if that makes a difference. They were on the car when I bought it and they like kinda cheesey.

04-10-2008, 11:36 PM
ok if its your frps and the car will not start go unplug everything from the frps and the car should start right up dont leave it running long but if its frps thats one way to find out. If your running a bap on top of the gt pumps thats a bit excessive and un-needed.

If the fuel pump install was done correctly you shouldnt need a bap till in the mid 800's with the gt pumps and correct tune/setup.

04-10-2008, 11:37 PM
oh and why did you ask where I worked before in the other thread?

04-10-2008, 11:40 PM
I think there's a small hose and the electrical plug, unplug both? I agree w/unplugging the BAP. I'm not even driving the car hard as I'm breaking in the the new clutch. They also said they removed the PPRV in the tank which should've helped control the spike. Doesn't sound like there's an easy answer on this one.

04-10-2008, 11:46 PM
oh and why did you ask where I worked before in the other thread?pprv doesnt help control spike as much as it does keeping fuel from flowing back into the tank its more like a reverse flow check valve.

Yeah if I remember correctly its 1 vaccuum line and 1 electrical connector on the frps if you disconnect them the car should start up if the frps is bad, although dont allow it to run long like this.

Depending on how the bap is wired in simply unplugging it may not work as it may power either fpdm or the pumps directly if you unplug it your pumps may not turn on

are you running a single or dual fpdm setup? Im assuming your using the stock fuel hat? Did they run wires seperately to each pump or just daisy chain them?

04-10-2008, 11:51 PM
I was really asking where you lived in the US because you sound like you know what you're talking about it and I'd have you look at it.

I'm having the dual fpdm setup but still have the stock hat. Not sure how he's setting it up but can call to ask. I'll ask about the BAP too.

04-10-2008, 11:54 PM
you can run dual fpdms with the stock hat its just more difficult to get all the wires through the hat without it leaking gas. Plus using the proper hose of sae30r10 for submersion in a gas tank, makes it difficult to as the hose is very rigid and you have to becareful not to pinch it closed and have a nice free flowing curve in it.

I would ditch the bap and sell it to recoupe funds for other things heh. Im from newton, nc id look at it if you were local but sounds like you got someone to delve into it already.

have them remove the connections from the frps if car fires up its your culprit.

good luck with it

04-10-2008, 11:56 PM
Interesting post from someone else who had the same problem. "I pulled the PPRV to get better fuel flow and a week later it goes south on me." I wonder if it's somehow related to pulling out the PPRV.

As for the hat, I'll have them order the hat and all the stuff that goes with it from Lethal Performance.

04-10-2008, 11:58 PM
well ive removed pprv from several cobras now and havent seen them pop a frps and I know of one guy thats a member here thats local to me that popped a frps with the pprv still in the tank so I dont foresee it being the real culprit.

04-11-2008, 12:04 AM
ok, i was thinking it was more tune related and heres a good quote from a reputable tuner in the 03 community. This was in reference to the kb restrictor discs

If everyone would just get their returnless fuel system properly tuned in, you wouldn't ever need to use such a device.

I've also seen the discs cause problems in some vehicles with aftermarket upgraded fuel systems (erratic fuel pressure), and drilling the hole, or removing the disc altogether, rectified the situation. The hole is approx. 0.30 in diameter, but they seem to be a bit inconsistent from one to the next.

04-11-2008, 12:04 AM
Thanks again for the help, I'll have them disconnect the BAP and get an after-market hat. More to follow...

04-11-2008, 12:06 AM
good luck bud keep us informed hope it all works out ok

04-11-2008, 12:09 AM
Me too, I'm looking forward to racing it!!!