Cat failure stops car from running?

[narfire]

Wondering if you have something rolling around the trunk. The ground to the fuel pump is located near the driver rear light. I can't remember exactly but I think there is a stud it connects to. Is the connection good? Intermitant fuel pump?
Just a thought cause I believe you have checked damb near everything else... twice.
Chris

[BartusCompater]

-I checked the distributor today, looked in the cap, tried wiggling it and didn't notice anything abnormal. Just a wee bit of metal shaving under the rotor but that seemed normal.

-I'll have to pick up one of those flush kits. And find a place where I can spill more coolant/dispose of it responsibly so that I don't kill any of the neighborhood cats.

-I've had my eye on the fuel pump throughout all of this. I noticed that a P.O. had rigged up a their own ground for the fuel pump, just a wire going from the connector straight to a small screw that's just drilled into the bottom of the body near the pump.

-Since getting the car back I've been driving it around short distances (2-5 miles stop and go) and it hasn't been giving me problems. I'm sure that if I were to drive it for more than around 30 minutes straight though, that it would start acting up again. I'm entertaining the idea that maybe if I keep driving on it the problem will get bigger and emerge to show itself. This is a hot new auto-mechanic strategy I'm inventing here.

[BartusCompater]

So I've been continuing to drive it around town, just going from place to place making sure that it sits for a while before I have to drive it again. Haven't gotten any problems out of it. The only thing I've noticed is that whenever I go to start the car it has to fire up, die, and then be started again before it will stay running. Maybe I'm losing fuel pressure or something like that? A while back (before this problem started) the mechanic that I've been taking it to replaced my fuel hoses/clamps etc. on the fuel rail and reinstalled it.

This makes sense to me because when the car DOES start to die after being driven for extended periods of time, it starts back up when I hold the throttle down.

This is just a guess though, and I don't know if it would account for the fact that the car only dies after being driven for a while.

[BartusCompater]

BREAKTHROUGH!!!!

Or should I say... BRAKEthrough. Drove the car around town today to replicate the problem again and see if I could figure out what was going on. After driving around 10 miles it stopped in the road again, so I applied the throttle, started it back up, and parked it. Died again as I came to the stop.

Started it up with it parked, it idled and everything just fine. Had it running for about 5 minutes while I fiddled with hoses and wires, making sure everything seemed to be okay. Didn't die. Ended up driving it back home a couple of miles, with it dying as I came to a stop several times. Each time I just held the throttle down a little and it would start right back up.

Got it home, parked it. Started it back up again, having to hold the throttle down. Let it sit a little while. Stayed idling. Pushed the clutch in, stayed idling. Pushing the BRAKES alone, died. Started it up again. Pushed the brakes, died. I did this several times. It looks like what's going on is something to do with me depressing the brake pedal is causing it to die, but only after having been driven for an extensive period of time.

WOOHOO, progress!

[manoa matt]

The diaphragm in the brake booster is busted. Either look for a used booster, buy a new one, or plug the fitting on the intake manifold and go without boosted brakes.

[BartusCompater]

AAAAH, Matt, you are my hero! I've been trying to get to the bottom of this problem for 5 months now! Looking into brake boosters... will update soon.

[BartusCompater]

Where should I start aside from international-auto if I'm looking for a brake booster? I don't suppose there are any alternative parts websites? O'Reilly definitely doesn't have it. Any other makes/models of car that used the same brake booster that I might be able to find at a salvage yard (though I'm not sure I'd trust a salvaged one). Anyone with a good booster they'd be willing to sell me?

[TulsaSpider]

I have one. $50 plus shipping. I tested it. I'll test it again if you are interested. I have had a used one on my car for two years so far so good.

[divace73]

who would have guessed the brake booster.
What would be the reason, I imagins if the diaphragm is broken then more air would enter the chamber which would normally cause it to idle higher?
Can anybody shed light why it would stall.

[majicwrench]

Brake booster can cause stall on FI car if diaphram is allowing air into intake. Any un-metered air, which does not go thru the AFM, will cause the car to run too lean, and could potentially cause stall.
That said, there still may be "the rest of the story". Would be odd for a brake booster diaphram to be intermittent. Am not gonna read back thru all those threads, but methinks something else may be goin on. But keep fingers crossed......could also just plug booster, car will still stop, and see how it goes for a few days.

[manoa matt]

I'm with Magic on this one. Plug the vacume port on the manifold where the booster attaches and run it around for a few days to see if anything else happens.

I've looked through the thread and I replied 4 times. Each successive solution suggested was to combat a different set of symptoms, so I may not be convinced just the booster is a fault here.

[So Cal Mark]

didn't you notice an unusally hard brake pedal or extra pedal effort needed to stop? Or a hissing noise with the pedal depressed? I normally get boosters rebuilt, that's about half the price of a new one.
You may have a master cylinder leaking fluid out the back and into the booster. That will ruin the booster diaphragm quickly

[BartusCompater]

You know I didn't ever notice any tough braking or hissing noises. It is odd too because it only dies after the car has been driven for a while AND I hit the brakes.

I looked at the booster the other day and I noticed that if I play with the hose which runs from the booster to the intake I can get pressure to hiss out from the rubber grommet where it runs into the booster. Not sure if that's normal.

[So Cal Mark]

if you tweak the fitting in the grommet enough to break the seal, you will hear a vacuum leak. I'll agree with the next step in the diagnostic tree; disconnect and plug the vacuum hose then drive the car and see if your stalling is cured

[BartusCompater]

I looked around my house the other day for something to plug it with and I couldn't find/think of anything that seemed like it would work very well. Suggestions about what I should use? Do they sell caps for this kind of thing at auto parts stores?