Carb

Typrus · Post by **Typrus** » Tue Dec 07, 2004 7:16 pm

Alright. I'm having a few issues with my baby's carb (I believe it is the carb).
When accelerating hard, I get a gasoline fume in the cab that isn't present otherwise.
My idle is by no means stable. It usually bounces 150-500 rpms when idling, and drops as low as 500 rpms sometimes. This makes uphill starts (without stalling or rolling backwards) damn near impossible.
It doesn't want to run very well below 2k RPMs
It feels kind of gutless, even for a 60 horse engine.
Don't know mileage yet (don't have a job so can only put in 2-6 gallons at a time)

Help?

takza · Post by **takza** » Wed Dec 08, 2004 8:12 am

Find your EGR and as a test...pull the vac hose off of it...plug it with a golf tee. If this stops the problem then it's probably the vac modulator or something else that controls the EGR.

Typrus · Post by **Typrus** » Wed Dec 08, 2004 9:36 am

Well, my EGR tube isn't exactly a solid seal to the manifold. Have to get a new tube. I'll give that a try, but I don't think I have a golf tee. Might have a spare pencil-part though.
Supposing it is the vacuum modulator, how do I fix that?

Typrus · Post by **Typrus** » Wed Dec 08, 2004 3:06 pm

Now that I'm home.. I'm going to try that.
By the way, my mileage is roughly 25.25 mpg. Not bad for how I accelerate!
Update on the stinky condition- it also appears to appear when I'm in too high of a gear.

The hose wont come off lol. But apparently my EGR tube (the one to the manifold) is now dead shot. I'll have to see if Autozone or Napa stocks them.
I plan to de-gunk the carb today with some SeaFoam spray, if I can find it in my garage. That should help my mileage out if nothing else.

Just refilled tank- 20.08 mpg currently.

Gelok · Post by **Gelok** » Wed Dec 08, 2004 3:48 pm

I have an '86 SR5 deluxe wagon and it was doing the exact same thing, it would reak like gas as soon as the engine was warm. I had the damdest time trying to locate the leak turns out it was my fuel pump. Check it out!

takza · Post by **takza** » Wed Dec 08, 2004 7:06 pm

Typrus wrote: Well, my EGR tube isn't exactly a solid seal to the manifold. Have to get a new tube. I'll give that a try, but I don't think I have a golf tee. Might have a spare pencil-part though.
Supposing it is the vacuum modulator, how do I fix that?

Be REAL NICE to your EGR....Toyota wants a fortune for one. Might try furnace cement to fix that tube leak...found in hardware stores...or a muffler bandage?

There is a test for the vac modulator.....mine almost passes.

Fact is...my car runs best with no EGR...EVAP system...not sure about the O2 sensor. Not saying to just remove all this...just that to diagnose running problems it's possible to disable them one by one to see if they are causing a problem.

Typrus · Post by **Typrus** » Wed Dec 08, 2004 8:40 pm

What are visual symptoms of a leaky fuel pump?
How do you test the O2 sensor?

takza · Post by **takza** » Thu Dec 09, 2004 3:21 am

Typrus wrote: What are visual symptoms of a leaky fuel pump?
How do you test the O2 sensor?

The fuel pump is run off the cam and it can allow gas to get into the oil...sniff your dipstick for a gas smell? Can't see this from the outside.

O2 test uses a voltmeter I think...try downloading the FSM from the front page?

Typrus · Post by **Typrus** » Mon Dec 13, 2004 4:39 pm

Finally got to sniffing the oil. Sure enough, it is highly gasified. What now? It's obviously doing it to a good amount of fuel, because that fume gets dang strong, and I can't afford wasted fuel.

Lateer · Post by **Lateer** » Mon Dec 13, 2004 9:17 pm

It sounds like the diaphragm in your fuel pump has gone, dumping a little fuel into the oil each time it works.

If you've got oil down the firewall at the back of the engine bay, that's a real good indicator as well.

I can't think of anywhere else where there's the possibility of the oil and petrol mixing. The fuel pump is one of the few places it does.
Oh, and it's a bit of a bitch to get off, too. I reccomend removing the rocker cover to do it.
Use a socket set with a long arm to get to the two bolts holding the thing on and when you put the new one on, make sure you get the gaskets lined up nice and straight. Mine leaked for a while until I loosened it off and straightened the gaskets up.

The bouncing revs sound a lot like a butterfly valve in the carburetor isn't closing right. I'll go and have a read of the disassembly of a standard Tercel carb. You do have a standard one, yes?

When you find out what's wrong, Typrus, let us know. I wouldn't mind knowing that...

takza · Post by **takza** » Tue Dec 14, 2004 7:18 am

Typrus wrote: Finally got to sniffing the oil. Sure enough, it is highly gasified. What now? It's obviously doing it to a good amount of fuel, because that fume gets dang strong, and I can't afford wasted fuel.

Don't drive it....replace the pump...your rod/main bearings won't last...not to mention rings/valve train.

Typrus · Post by **Typrus** » Tue Dec 14, 2004 9:28 am

Oh boy. Grrrreat. Well, my parents will probably help me out on this as it is an emergency repair. Sigh. $50 is a bit more than I had hoped to spend.
How hard is it to replace the bearings, and what else has to go with it?
I'll probably change my oil when I get home, as we've got some spare oil around, and I have to use my car tomarrow.
I'd assume I'll need to pull my engine for this?

Lateer · Post by **Lateer** » Tue Dec 14, 2004 4:38 pm

For the fuel pump?
Hell, no. It's a simple swap, it's just getting to it at the back of the engine bay can be a little difficult if you're my size.

For the bearings, so long as you get to the pump quickly, you'll be fine.

Typrus · Post by **Typrus** » Tue Dec 14, 2004 5:09 pm

Will a NAPA pump suffice? I don't want to spend a huge amount on this but definitly want it to be right.
I'll check the service manual to see if it has fuel pump specs on it.

Typrus · Post by **Typrus** » Tue Dec 14, 2004 6:14 pm

Holy cow.. (cough cough cough) I am doing the Sea-Foam spray treatment right now.. DEAR LORD IS THAT SMELL ACRID! Ok- difference noticed with the Sea-Foam spray treat;
More responsive on/off the throttle
Slightly more stable idle
Considerably less surging below 2k RPM

I now need to use the in-tank treatment.

Okay, thing I noticed- when I put my hand behind the fuel pump while the engine was running, it came back out with a nice gas/oil mix on it. Lovely.

My dad has done a road-side fuel pump change on one of these before, so I doubt I'll have an issue changing that.

I'll let you know what happens.