I'm having trouble figuring out what is causing this weird behavior, but I have the feeling it's all related and possibly a vaccum leak. So I'm gonna describe the various behaviors in no particular order.

First is the brakes. They seem to semi-randomly lose pressure. Never ALL the pressure, but at a certain point the pedal will hit the floor. Normally it hits the floor only when I'm at a stop, in neutral. Now this is easily cured by letting the brake go and pushing back down... pressure is restored, but sometimes it starts losing pressure again right away.

It is not the brake fluid, bled/flushed the entire system today... expected that to fix it, since the brake fluid was literally dark brown. =O

Oh I recently bought this car, these problems have all been present from day one.

Second is the startup. The 3.5-3k warmup does it's normal thing... then at the point where it drops off a little, like down to 2k.. it starts pulsing, from 2.5k-2k about. I don't know if this is normal, it very well could be... I've seen cars with this kind of warmup.

Third, Idle is effected by powered things, such as the steering. Turning on the air conditioning then suddenly, at warm idle, turning the fan on full blast... will for SURE kill the engine within a second or two. Turning it half way up makes it idle poorly.

That's all I can think of right now.

Any help diagnosing this? Some things to check? I'm pretty new to these cars but I've done a lot of reading on them... and I've test driven a bunch... not that that really helps.

I swear I'll post some pics soon of the car!

And I'm in SoCal / SFV, anyone around here?

--Bob

 

ok for the brakes u can bleed them as much as u can it wont do nothing
if the pedal hits the floor on a stop light it means that your cup seals in the master cylinder are fucked and u probably need a new one

as for the steering and accessories turn on and idle drop it could be a clogged BAC valve cuz thats what makes up for the car ideling when stuff takes power away from the car.

and on top of everything u might still have a little vacuum leak when the car surges. But it can all be fixed in a day or two.

 

i agree..... your master is gone!! you can use the old "carb cleaner" trick to see if you have a vacuum leak.... its the quickest way to tell....... where in socal are you??? im in san bernardino/redlands???

 

Master cylinder, or any caliper could be leaking. If it leaks its sucking air back into the hydralics, this makes a loss of pressure.
How well did you bleed, did you spend a half hour with a buddy bleeding? Which bleeders did you use on the back tires? Did you bleed the master cylinder clean? of air?
we've all been there, trust me. You'll get used to havign to fix things...
The pulsing is more than likely a combination of fuel cut and a vac leak or unmetered/restricted air. On cold starts the car will idle high fir AWS , then back down to 2.5ish, then eventualy around 900 for a warm idle. It could be a range of diferent things that cause a pulsing t 2.5 on cold starts. Cold starts suck anyhow. If you're in a northern climate like me, get used to waking up early in the mornig to start your car. Anyhow, if you never reach a steady 900ish rpm idle, its because (generaly) incorrectly calibrated idle, or a vac leak. During Idle (No throttle, no load) There is a fuel cut at 1500ish rpm. If there is a vac leak that raises rpms, it will raise until around 1500, the ecu will fuel cut to bring it back down. Then again the leak will raise idle, this causes pulsing idle to the tone of 800ish rpm jumps up and down. Look for a couple (or just one) vac nipples not plugged in. there are a few million hidden ones on a 13b, and a few more million on a 13bt, so take the time to look.
sounds like your BAC isn't opperating correctly. the BAC is what compensates for extra power draw (AC, PS, Heater, whatever) during idle. It probably just needs to be cleaned. Do a search, theres plenty of threads on this. Basicaly, unbold the BAC, and clean the screw drive with carb cleaner, reinstall, done.

The BAC works by compensating for power loss by injecting air directly into the manifolds (by passing the throttle plates and DC chamber (on a n/a.) A combination of BAC injected *METERED* air, and increased injector-width simulates the driver holding the pedal down the exact amount to compensates for the extra power loss.
cheers

 

I'm on the east side of the Valley, near Sylmar.

So this is a bad master cylinder for sure?

I'm curious if it's safe to drive on now, I've been driving it like this for the past week... as long as I am careful to pay attention to how much pressure I'm losing and let the pedal back up to regain some while stopping, it doesn't seem to be a problem... is it one of those things where it could go out any minute or is it gonna be like this until I replace the cylinder?

How do I do this brake cleaner test? Damn I don't even remember if we have any brake cleaner in the garage... even if we have it it might be like 100 years old 'cause my dad never uses his stuff anymore haha.

EDIT: To answer that post I didn't see real quick, I had to bleed it by myself... I know that sucks, but I've done it plenty of times with other people. I also used "The Club" to hold the pedal down while I closed the valve haha. And I used the top bleeder valve, Haynes manual says to use that one... I will hate them if they were wrong. -_-

I thought about bleeding the master cyl. completely dry and then running it until the air was completely out. But I've never done that before, so I wasn't going to experiment, even though I figured it'd probably work the way I think it would.

--Bob

 

Fix the brakes, I'd be ******* pissed if you rear-ended someone in my family and caused them harm because you *thought* your car was safe to drive.

Fix the brakes. Please.

 

to do the carb cleaner trick.... start the car.....spray carb cleaner near all vacuum lines.... if your idle rises in the spot your spraying....its a vacuum leak! its very easy and effective!! but use carb cleaner......not brake cleaner!

 

Not really. And carb cleaner will combust in your face if you have bad luck. using water produces the same results and won't combust in ones face.

 

yeah, you can also get struck by lightning too..... ive done it a thousand times, and so has thousands of people.... a hairspray bottle can combust in ones face too.... but people still spray their hair!!

 

If the brakes lost pressure I've tested the E-brake, it works very well.

I've driven on it for a week like this, if it's not going to get worse I consider it something I can deal with.

If someone in your family cuts me off and slams on their brakes, which would be the only case where I could possibly come close to rear ending them, I'm going to get out and beat the **** out of them for wrecking my new car... I could care less whether you like that or not.

I drove this car with the brake problem, the first day I bought it, from San Diego to here in off and on bumper to bumper traffic.

Seriously man, thanks very much for your help... I will fix this problem hopefully even this weekend if I can hit the junkyard tomorrow and get lucky, but it's not a reason I should take the bus to work. I know how to drive safely, I'm not gonna go racing up behind people with fucked up brakes. Hell, not even with fully working brakes would I do that.

--Bob

 

I'm gonna do this vaccum test with a WATER BOTTLE, because it's easy to be safe like that... and why would I want to use carb cleaner anyway? Make kinda a mess.

If I hit the junkyard is there anyway quick way to test a master cylinder to see if it works? Yeah I know I'm pretty new to be "hitting" the junkyard... but I'm low on money and there's some other stuff I should look for there too. I know the general idea of taking a shitload of tools into the yard with you and such... so no worries on that. But I don't want to grab a non working master cylinder.

BTW Kenteth, sorry if I was harsh in that last post... I was/am pretty offended that you'd think I'd put other people at risk driving around.

--Bob

 

I'm just saying its not safe to drive a car with intermittent breaking-- even if the driver is experienced.

Anyhow goodluck with the leaks, let me know how it turns out. I'll be glad to help with anyway i can.

 

If your brake master is bad, buy a new one! Brakes are not a used part item. Espescially the master. You have no idea what you'll be getting out of the bone yard.

Check your local parts stores, get some prices and ask if they will price match, most will. Then get a new one and get another person to help you bleed the brakes.

I'm not trying to be harsh here, but the brake system is not the place for ghetto repairs. Do it right the first time so you and your car will be around to enjoy each other.