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Discussion Starter #1
Wen I pull the 1" line with the engine running should I hear a great intake of air?
Blazer's got an issue, starts fine cold, drives great cold, as it warms up it acts like shit; shudders, stumbles, dies, massive brake power loss, gets like 6 or 7 MPG, throwing codes 22, 32 and 45.
I been replacing sensors one at a time, now I think it is throttle body, or blockage in vacuum to master cylinder.
Motor is 100% solid, its just these stupid peripherals ailing it.

If I didn't live in california I'd have cut the cat and swapped a carb on long ago.
 

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If you pull the brake booster line off while the engine is running, you should have a great hissing of air and the engine will run rough and likely stall.

If you engine runs rough and the brakes require more effort to stop, then the booster may be leaking vacuum, not uncommon.

With the engine off, pump the brake pedal several times to deplete the vacuum in the booster. Now with your foot applying normal braking effort start the engine. The brake pedal should go down with the engine running if the booster is working correctly. If not, you either have no vacuum from the engine to the booster, or the booster is bad. A bad booster will upset the idle and running of the engine.
 

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Discussion Starter #3
Did the test again, it wasn't a GREAT hiss, just kind of mediocre.
What can cause weak vacuum?
 

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Discussion Starter #4
"pointing to cracked hoses, base plates leaks, manifold leaks, faulty carburetor or defective ported vacuum-operated switching valves. This also results in a too-lean air mixture. Low vacuum can result from low compression and burnt valves."

So I'm going to start simple and spray some aerosol ether into each one of my vacuum lines, I suspect blockage, I had to replace injectors a while ago and refused to buy a gasket kit for like $40 and used gasket in a tube, for some reason it never fully hardened, I fear it may be partially clogging TB internals.

I need this truck to conquer Donner pass to retrieve s few transmissions from Reno.
 

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The vacuum line to the booster is connected directly to the intake manifold. You should have strong suction at the disconnected hose when running. You shouldn't have any valves or restriction in the line.

The hose has connects to a check valve at the booster. It is possible that the check valve is bad and not letting air pass quickly. The engine side of the valve should have full engine vacuum. If you disconnect the hose from the valve you should have a great hissing and the engine will stall. If the valve is connected to the hose when you disconnect the vacuum from the booster it should still have quite a lot of hissing. You are creating a massive vacuum leak when you pull the hose, it should seriously upset the running engine.

 

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Discussion Starter #6
there is a definate diffrence between pulling the white (yellowed) plastic cylinder with the 1" hose connectd to it off the master cylinder body, and pulling the black hose from the throttle body off the black valve; I,e,. there is two one way valves, one looks like a fuel filter, and the otehr looks like this

But the engine runs better with it disconnected, the idle goes up, though the engine does not die.
 

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starts fine cold, drives great cold, as it warms up it acts like shit; shudders, stumbles, dies, massive brake power loss, gets like 6 or 7 MPG, throwing codes 22, 32 and 45.
It sounds like your engine is running rich (starts fine cold, drives great cold, as it warms up it acts like shit), cold engine don't mind a rich fuel mixture.

So when you pull the vacuum hose off the booster it leans the mixture out.

First eliminate the brake booster as a problem, as I described above.

Then deal with the lean running. Fuel pressure, Oxygen sensor, etc.
 

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Discussion Starter #8
Yea been chronicling my issue over in Some codes . . .
Replaced O2 sens, TPS, CTS, injectors, replaced some cracked vac lines.
Now I'm trying to think outside the box and figgure out what is causing it to run rich.
Throws 22, 32 and 45 - all aside from TPS points to vacuum leak.
I bought a couple cans of aerosol ether (carb/choke cleaner spray) and blasted all the intake/vacuum lines and the throttle body exterior, did get a rise out of it when spraying the back of the TB, so I might just chance rebuilding it.
I could boot it to reno and back but I know I'd go though a tank and a half or more of fuel.
 

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Discussion Starter #10
I like easy. Will do tomorrow. Post results.
 

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I had to replace injectors a while ago and refused to buy a gasket kit for like $40 and used gasket in a tube, for some reason it never fully hardened, I fear it may be partially clogging TB internals.
You talk about pulling the fuel injection and cat and throwing a carb on there, but you do a shit job of actually fixing what you have.

Spend the money on the TBI kit, make sure all the vacuum passages are clean of carbon build up, and spend a buck or two replacing all of the vacuum lines. The rubber stuff is like 25 years old now, it don't last forever.
 

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Discussion Starter #12
Thank you for your input, your cynicism and elitism has been noted, archived and appreciated for its value.
 

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Discussion Starter #13
Might have something to do with this oil under the TB.
Hope thats not due to blowby . . .




 

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Discussion Starter #14
all symptoms corrected on first drive, though it still threw 22, 32 and 45 I forgot to clear codes before I drove it so they might be ancient history.
 

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Discussion Starter #15
Ran perfectly on first drive, after I cleared the codes and did it again its running pretty much as it was before. code 22 is gone 32 and 45 remain.
One simple question, running for X amount of time with EGR vac capped off will clog the catalytic converter? Yes?
 

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Discussion Starter #16
Opened the smog pump tube off the manifold, no change.
Stuck a little hole in the cat inspection plug, ran even worse.
WTF?!?!
 

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You talk about pulling the fuel injection and cat and throwing a carb on there, but you do a shit job of actually fixing what you have.

Spend the money on the TBI kit, make sure all the vacuum passages are clean of carbon build up, and spend a buck or two replacing all of the vacuum lines. The rubber stuff is like 25 years old now, it don't last forever.
Damn dude...what's up acting like a dick?:moon:

Glad you got if fixed man.
 

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Discussion Starter #18
Ran fine on I-80 to Reno to retrieve the transmissions for my tercel, upwards of 15MPG. Even did a little 4x4ing out there.
the backfiring while coasting after downshifting is entertaining, scares the shit outta people, muffler is bloated where the exhaust line detonations have bulged the center out, creasing the sides.
Still have no idea what the core cause is. Putting this thing on hold put my time and money into this toyota.
 

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I used to love popping a backfire at assholes that used to ride my bumper on my 85 Chevette...seriously fun watching em jump...
 
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jimmykicker
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