jose08m5

How's it going guys, I have an 01 Maggie c5 with a walbro 450 and a bap. My problem is I'll be driving the car normal and all of a sudden it loses fuel pressure and shots off and then takes a couple minutes to turn on again and other times it'll turn off and then before I even have time to stop the car it turns right back on. I kinda feel like a lose wire somewhere but not sure also something I find weird is when I pull the fp relay it slides up super easy while other relays are harder to pull out. The relay is also very hot when I take it out. Thanks for your help in advance.

Jose Jalapeno

sounds like a loose wire or perhaps the fuse holder has melted and causing poor contact...pull the fuses to the BAP and check them...they may look ok but you need to pull them to see for sure...I think you have two fusible links with that setup

jose08m5

Gonna check that once I get home. If it's the bap fuse what do you think might be causing it to blow all of a sudden?

BigGun

A fuse would not come and go like your problem does. I would look at that loose relay closely.

LoneStarFRC

Look into your BAP setup and how it's being activated (vacuum? rpm?).

If it's cranked up (or activated) all, or most of the time, your FP is getting hit with much higher than normal voltages, like 15-17 volts. The contacts in the FP relay are not particularly happy with all the extra current flow being demanded by the FP either, hence the hot relay. Not good.

jose08m5

The bap is being activated thru vacuum.

LoneStarFRC

Did you install it yourself? Previous owner?

If your going to run a BAP on a street driven car, I recommend using an rpm-activated switch, since it will only hit the pump with higher voltages when you go WOT (when you mainly need it in the first place). There are several on the market (Zex, Jegs, Intellitronix) and some can be adjusted to suit your "turn on" points.

Vacuum set-up hits the FP every time you start the car (or even just turn the key on) as there is no/low vacuum during that time plus, depending on where the vacuum switch is set, it may also activate at other times when you really don't need it, i.e. part throttle during regular driving if the vacuum drops below the threshold of the switch.
Bottom line is more wear and tear on the FP. The higher current draw being demanded by the FP that is going through the FP relay contacts, will prematurely shorten it's lifespan as well. The fact that it's getting hot is a warning sign, plus fitting loosely won't help matters either.

I agree with BigGun, a fuse won't open then close. That sounds more like a circuit breaker somewhere in the circuit (inside BAP maybe?) Jose also makes a good point about a possible loose wire/connection somewhere as well.

You may also have more than one problem and I wouldn't rule out the BAP it self as a potential trouble source either, since it has direct contact with the FP and it's functioning.

HTH

jose08m5

So I fixed the fp relay and nothing. Does anyone one no where the fp grounds are so I can check those and if not the problem remove the bap

LoneStarFRC

IIRC, check on the frame rail behind or near the left rear wheel. There's a ground point there (stud). The BAP may have it's own however, depending on how it was mounted.

jose08m5

So I disconnected the bap and the car is still acting the also one thing I noticed is that when I get on the car the fuel pressure will jump up to 68 psi which is normal and then creep back down to the 50s do you guys think it's the fuel pump?

jose08m5

so I think I found the problem