Bad FPR, injectors or relay

[foxbrand]

So, my Lebaron (1995 convertible v6) is having starting problems, I have spark and compression. Also worth noting, the battery is having problems holding a charge, I have charged the battery a number of times to jump the Lebaron, which, does nothing really to start the car. BUT, every so often, the engine will fire twice (once went up to 2000 rpm for a half a second), then die, the engine will always turn over if there is enough charge in the battery. Anyway, onto what I have identified as what the problem could be, first, I thought it was something with the anti theft, or any of the fuses, well, all fuses are fine, those that were blown were replaced, I have tried everything with and without the anti theft disconnected (no change), so, I tried putting some fuel into the intake (after disconnecting the battery for a few minutes with it on my charger) through the throttle body, reconnected the battery, flipped the key, and vola, car instantly revs to 5800 rpm (for a solid 2 seconds), I slightly backed off the gas pedal, and the thing died again. Is it possible for this the be a symptom of a bad fuel pressure regulator, injector(s), or is this closer to the sign of a bad fuel pump? I am able to get the pump to prime, but that's about it by removing and reconneting the fuse for the fuel pump. I have done reading on 3si about a similar problem a fellow had with his 12 valve, it was brought up that it could be a bad relay, could this be the case?

speaking of the fuel pressure regulator, what is the stock fuel pressure on these cars?

[zin]

Definitely check the fuel pressure, that will determine the next step, it should be in the 40-50psi range, I don't recall exactly what the V6 is supposed to be at, but if it's close to that, the relay, pump and regulator are probably good.

Once there is a gauge on the car we can see if it holds pressure with the key off,and if it holds pressure under load, that will go a long way towards diagnosing the problem.

Mike

- - - Updated - - -

Definitely check the fuel pressure, that will determine the next step, it should be in the 40-50psi range, I don't recall exactly what the V6 is supposed to be at, but if it's close to that, the relay, pump and regulator are probably good.

Once there is a gauge on the car we can see if it holds pressure with the key off,and if it holds pressure under load, that will go a long way towards diagnosing the problem.

Mike

[black86glhs]

Mike has the first step correct. Check the fuel pressure. It will tell you many things.

Signed,

The fuel pump whisperer.

[foxbrand]

50 psi while cranking, it immediately plummets to zero psi after I stop cranking within a couple seconds

[zin]

That can mean a bad regulator, or (I think more likely) a bad check valve in the fuel pump/assembly.

Either way, it should hold pressure, and if either of these are bad, it'll drop to zero almost right away, though the check valves usually bleed away over time...

If the hose used for the pump to sender connection wasn't of the correct rating, or is original, it may have "melted" like the one in my Omni, today's fuel with all the alky and additives, doesn't play well with the older hoses...

Try pinching off the hose from the fuel filter to the rail while someone cranks it so you can try to trap the pressure between the pinch and the regulator... if the pressure holds, the regulator is ok (or at least not leaking), if it goes away, you know you have a bad regulator at the least.

If it holds, I'd bet on a blown/melted hose in the tank... or a bad pump/check valve (in the pump).

Good luck!

Mike

[cordes]

If it's holding 50PSI while cranking with vac to it then it should be good enough to run.

[foxbrand]

Got the upper off, is it possible a cracked intake manifold could cause this?

[cordes]

Got the upper off, is it possible a cracked intake manifold could cause this?

If it is leaking there it certainly won't be helping the car run right at all.