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-   -   What's the worst damage a blown fuel pump can do? (http://986forum.com/forums/boxster-general-discussions/37340-whats-worst-damage-blown-fuel-pump-can-do.html)

VFX 09-11-2012 09:09 PM

What's the worst damage a blown fuel pump can do?
 
What's the worst damage a blown fuel pump can do?

I have 90k km 2005 987 2.7L

It lost power & went into limp home mode on the weekend & then stalled once the revs were low enough as I approached a junction.

I had towed to a well known & respected Indy who said it was a blown fuel pump.

Fuel pump replaced and the car still wont start.

They now say that I need to replace all my plugs as they've been destroyed & that fuel flooded the whole shebang causing the failures.

What I want to know is at worse, what will a blown fuel pump do the engine?

How will it effect the heads? What sequence of events from the pump failure to head damage occurred?

I'm not hugely mechanically minded but to my mind, wouldn't the fuel filter catch the debris if the pump grenaded itself? Wouldn't the techs have spotted the fact that the heads were iffy whilst diagnosing the problems in the first place?

I've gone from a $500 replacement fuel pump to a potential head rebuild & not too happy.

Your thoughts & opinions requested!

.

tonycarreon 09-12-2012 04:20 AM

i'll preface my remarks by admitting i'm talking out of my ass here, so...

your fuel pump is built into the fuel tank so when it goes, it should pretty much just cause the engine to stall for lack of fuel. i can't imagine a bad one would flood the engine. fuel injectors should stop the engine from flooding, along with egas monitoring everything...

when the pump goes, it usually makes some noise. did you notice any odd / loud noises while you were driving before this happened? did you have any issues with starting the car - kind of like you were out of gas...

go down there and ask them to show you the fuel pump relay (the fuse) if they can't find it or show it to you then it's time to get it somewhere else. this is the first thing i would check before replacing the pump itself.

Flavor 987S 09-12-2012 04:41 AM

Can't help you. Tony's advice above sounds right.

What would casue a fuel pump failure? Did you consistanty run your fuel level low?

Mighty Shilling 09-12-2012 05:23 AM

Yeah. When a fuel pump fails, the fuel flow stops, not becomes a deluge that somehow gets past the injectors and fouls everything.

Check the fuel pump relay and make sure it's getting power and you're getting fuel pressure...

And find a new shop...

And in regards to the fuel filter catching debris, you don't have a fuel filter. Your car has a non-return fuel system. at most it's equipped with a strainer on the fuel pump. The techs if diagnosing a fueling issue, may not have caught the heads ahead of time, unless there was a problem reported with the head. Generally if you say that there's an issue with your knee when you go to the doctor, do they check your wrist? probably not. Again, that's assuming the shop is correct in their diagnosis of a head issue (which I seriously doubt)

jcb986 09-12-2012 05:37 AM

I agree with the guys about your issue. The only way you could have damaged the heads is thru the engine misfiring or backfiring. Just like a doctor who says you need a triple heart by-pass...you get a second opinion.:cheers:

cheetah 09-12-2012 05:45 AM

I had a fuel pump fail at 65K. That morning started the car up, just one little stutter for a second, chalked it up to just how these engines sound sometimes.

One the highway about one hour later, just one more little stutter and the car started coasting. Real smooth, no sound or jerking. I pulled over, got it towed home, and plugged in a fuel pressure gauge. No pressure, so I bought a new pump.

Of course, I had 3/4 of a tank of fuel. But with elbow length gloves I did not have any problems replacing it. Once replaced, I let it prime the pump for a minute. The first start took a few seconds to finish getting fuel to the injectors but it started right up, never another problem.

Mighty Shilling 09-12-2012 05:56 AM

Quote:

Originally Posted by Flavor 987S (Post 305717)
What would cause a fuel pump failure?


driving :D

in all seriousness, It's a mechanical part. expect it to fail at some point. it WILL NOT last forever

VFX 09-12-2012 07:16 AM

I'm not surprised or annoyed by the fuel pump failing.

I'm thinking maybe the shop either misdiagnosed the problem in the first instance or are trying to fleece me as I questioned them why they were $400 more than the dealer to replace the fuel pump.

Either way I'm looking at a good few G's

.

VFX 09-12-2012 07:19 AM

Btw - I did not know know it was a fuel pump issue when I had it towed to them.

They diagnosed that after checking the car over themselves.

.

Ghostrider 310 09-12-2012 07:41 AM

I vote for potential fleece or honest misdiagnosis, electric fuel pump, can't see the related failure you were told about unless it's just a coincidence that they found the two problems at once. I had a watch battery replaced, the normal rate 6$ went in the P car with a nice watch given to me by the company, 6 immediately became 10.

Flavor 987S 09-12-2012 07:57 AM

Quote:

Originally Posted by Ghostrider 310 (Post 305751)
I had a watch battery replaced, the normal rate 6$ went in the P car with a nice watch given to me by the company, 6 immediately became 10.

A watch with a battery? Really?? I only thought Perfectlap wore those.:p;)








Sorry, I had to.

Ghostrider 310 09-12-2012 08:04 AM

I have a self winding unit as well but most of the rest of the collection require batteries. I don't see where the insult is anyhow, a lot of smooth watches require batteries, the one I was servicing is a Movado, it's a nice piece.

white out 09-12-2012 09:10 AM

Quote:

Originally Posted by VFX (Post 305702)
They now say that I need to replace all my plugs as they've been destroyed & that fuel flooded the whole shebang causing the failures.

What I want to know is at worse, what will a blown fuel pump do the engine?

How will it effect the heads? What sequence of events from the pump failure to head damage occurred?

First off, the shop is either a scam or an idiot.

Some fun facts:
- a dead fuel pump will not flood an engine
- dead fuel pump is like running out of fuel, chance of any damage with it shutting off is almost zero.
- the real worry about a dead fuel pump is when it's not flowing 100% and the MAF can't be scaled enough to add more fuel for the air intake, thus creating a lean situation and making your engine go boom. This would only happen at WOT.
- Head damage? lol. If there is detonation and part of the bottom end which blows up takes the head out as collateral damage.


Can you give us more input on what the car was doing when you drove it last.

Nick

VFX 09-12-2012 09:28 AM

Car suddenly began to feel down on power, I then noticed it was trying to be in the highest gear possible (running in 5th even at low speeds under acceleration). When I got to a safe place to stop the car stalled just before it came to a rest.

Engine was slightly noisier than normal during this time.

.

white out 09-12-2012 10:16 AM

I assume tiptronic. Sounds like something in the transmission.

Nick

The Radium King 09-12-2012 11:21 AM

if the fuel pump was gone and couldn't supply adequate fuel on a consistent basis then the computer *should* have thrown a code about inability to attain appropriate air/fuel mix.

VFX 09-12-2012 11:39 AM

If the box was out the engine would still start & not kill the valves & plugs right?

Spoke to the shop again & they're admitting that they diagnosed it incorrectly & have now run other tests on it.

Compression very low & timing is out.

Could be a broken balancing shaft?

Any ideas?

Sounds like I'm racking up a bill large enough to have bought & installed a 3.2L already!

.

tommy986 09-12-2012 11:40 AM

time for an upgrade!

jcb986 09-12-2012 11:57 AM

Since they diagnosed one thing and now coming back with another...I am wondering, are they good enough.:ah:

VFX 09-12-2012 01:04 PM

Jcb I'm wondering the same thing.

They're very well respected & been around for a long time so I kinda trusted them.

.


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