This pic is the vacuum hose(silver tape) going to the EFI
https://www.yotatech.com/members/mud...efi-intake.jpg


round check valve in between booster and EFI
https://www.yotatech.com/members/mud...alve-thing.jpg


They appear to be the only vacuum lines that would be in connection with the booster

 

I believe you could take the check valve out and try blowing through it, if you wanted to check it.

By vaccuum leaks, I actually meant within the booster itself. A quick test is to wait a couple of seconds after turning the engine off and seeing if you still get one or two good brake assists. You know how the pedal gets pregressively harder if you press it after the engine is off? That's the vacuum being used up in the booster. The check valve lets you store a little vacuum, but only enough for a couple good pushes. Sometimes the diaphragm within the booster springs a leak and the booster stops working like it should.

 

I will check today, bet the booster isn't cheap to replace. That would be my luck, I'll bet its a pain to change too. But it wouldn't surprise me at all I think that booster is original parts...older than dirt...

 

You're right, about $150 at RockAuto.com.

 

Yep, I found it at OReilly's for about the same without shipping. So I will have them order it. Its not something I want to replace a used part, but wished I didn't have to replace right now. The state brake check cost 150.00 too

 

If you can, look up a vacuum diagram and make sure the check valve is operating (blow through it one way, then the other. Air should only flow one direction) and then check that it's inserted the correct direction. Someone might have switched it around backwards.

 

Didn't get to the truck today its been pouring rain and I have no garage. But we are supposed to have good weather tomorrow and I will go over the vacuum diagram and check for airflow direction on that check valve, test the pedal and bleed the system. I want to bleed the system because I have
had the bleeder valves open a couple of times because of work on the wheel cylinders, and I need to replace the bleeder valves on the front wheels.

 

Still pouring rain...weather report wrong again. Guess I will have break out the rain gear.

 

You could do the test I mentioned in the rain pretty easily. Just start the engine and kill it after a few seconds. Wait a minute and see if you still have some assist on the brake pedal.

 

I did a couple of tests on the booster, Operating check: Press the pedal several times with engine off to make sure there is no change in reserve distance- passed


press the pedal and start the engine check to see if pedal drops slightly- passed


Air tightness test-like you said turn over engine let it run for a couple of minutes and turn it off. press pedal slowly three times to see if there is a gradual rise in the pedal position- passed


and the last test I did was to press the pedal then shut off the engine to see if pedal would drop- passed.

And you were right I did all this and stayed dry...lol

 

So, now that all those tests passed... what's your next step?

 

I agree. I think that we can safely rule out your booster and the check valve.

Were you being literal when you said that muck and mud came out of the LSPV? That sounds really bad, actually. As you probably know, brake fluid is hygroscopic and so tends to absorb water from the atmosphere over time. Too much water, and you start to see rust building up inside your braking system.

I hate to say it, but you have done the ultimate thread hijack. We started out talking about Gevo's problems, but now that he has it all figured out, we are only talking about yours. I really think you would get a lot more responses if you started up your own thread. That way we can address all of your problems (well, truck related, anyway ).

 

LOL at sturmrow's thread hijacking comment...

muddmadness, this is true. Just PM one of the admins and ask them to move the responses from here dealing with your issues to a new thread so you can have a clear record, and others can use it in the future when they search for similar issues.

I don't particularly mind, future users will

 

Just my luck, the smog ref that looked at my truck is the regional manager for the smog referee program. But I did my research today and found out who his bosses are...just want my plates. Going for my brake and light check on the 13th...hope it goes well

 

I just read gamefreak point out in another thread that the 225 tire size gives about 9 miles more (to every 100) on the odometer as the correct tire size of 31... This means that I am getting about 12.5 mpg in fuel usage.. which to me says there is still an issue.

I am going to plug the multimeter back into the diagnostics port and drive around and note the results. I am thinking that the O2 sensor may be damaged... What are some not so obvious indications that it is damaged? During the test the FSM says to count a minimum of 8 voltage spikes in 10 seconds. What if I get the 8 voltage spikes, but the voltage is erroneous, how can I tell? The other test it says to see where the voltage reading is depending on which indicates rich or lean... How can I confirm the voltage is coming form a properly working O2 sensor? (what if it's 1 volt off..?) Am I beating a dead horse again? Should I bite the bullet and blindly get a new one to test with?

 

You can review my post #62 for the details of how the O2 sensor loop works, but to briefly review how you should look at this...
1) When you short TE1 to E1 and measure VF1, you will see the output of the O2 sensor as the ECU sees it. So, if that signal is cycling 8 times/10 seconds, the voltage from the O2 sensor is adequate to give good information to the ECU.
2) The switch point of the O2 sensor as compared to the mixture in the exhaust pipe is not likely to be wrong. That switch point is set by basic chemistry. However, the O2 sensor has two "sides" to it, a fresh air side and an exhaust gas side. If there is a leak between those two parts of the sensor, it can give false readings.
3) If the O2 sensor is cycling, the closed loop operation of the engine is OK. However, the engine spends a significant amount of time in open-loop operation. Any time you are accelerating at near maximum engine performance (which, given the power of these engines, is almost anytime you are accelerating at all!:-), or going up a significant hill, the system will drop back to open loop. In that case, mixture is set by the preset map in the ECU. If the map is biased toward rich, the engine will run rich during those times.
4) You can tell if the ECU map is biased toward rich by measuring VF1 (with TE1 open) while the engine is in closed loop operation. If VF1 measures near ground, the ECU map is biased rich and the O2 sensor loop is providing signicant correction durng closed loop operation to keep it in the stochiometric region. Conversely, if VF1 measures near 5 volts while in closed loop, the ECU map is biased lean, and the O2 sensor loop is enriching the mixture. Ideally that voltage should be near 2.5 volts, meaning the O2 sensor loop only has to make fine tweaks to keep the mixture where it needs to be.

So, if you are measuring near 0V on VF1 while in closed loop operation, your ECU map is biased rich. Anytime the engine is running open loop, you'll be running rich because the ECU is ignoring feedback from the O2 sensor and just using its (erroneous) map to set the mixture.

As I've pointed out before, the most likely causes of an ECU map biased rich (operating on the wrong portion of the map) are (1) injectors sized too large, (2) the AFM telling the ECU that more air is entering the engine than actual, (3) "too-cold" reading from the intake air temperature sensor, or (4) "too-cold" reading from the coolant temp sensor. Those are not the only ones, but they are the biggies.

 

I had the same thing, n change the O2 sensor. you got to make sure the diameter of the O2 sensor match the old one because some manufactures makes with different diameters.

 

Got a call back from referee today, he is still sticking to his guns. But he was at least in a better mood than the last time we talked. I tried twice today to speak to DMV and twice they put me on hold and then hung up...makes me think the referee is right. The operator said she had to place me on hold to talk to her boss to see what needed to be done and then the phone went dead. Put in for another call back I am just going to ask for a super and get some names. Frustrated with a broken system

 

RJR,
I have post # 62 and others very fresh in my head So, I went ahead and did the tests again. The results, I documented with a video. In summery, when TE1 is connected, the voltage does cycle just about 8 or more times per 10 seconds, but it is not steady and not very consistent. I don't know how to judge if it's steady and consistent enough or not... Without TE1 connected, voltage at idle is nearly 0, the voltage under 2000+ rpm accelleration (but under 3000) starts at 3 to 4o volts then within a couple of seconds drops to 1 volt and stays there untill i release the throttle. Sometimes at throttle release it would go to 3-4 volts and linger for a while then drop to very near 0 volts again..

I apologize for the motion sickness you may get by watching these

Video 1. TE1 connected

Video 2. TE1 Not connected

Also, keep in mind my AFM is 4 clicks lean (tighter spring), perhaps I have room for more. RJR, i will triple check all of the sensors involved and make sure they are within spec still.

I purchased the following Denso O2 sensor:

 

In your first video, the O2 sensor starts out switching at about the right frequency, but later in the video it really speeds up, to 2-3 times/sec. Also, it doesn't really go to zero. If it is spending most of its time at a high voltage, that indicates a rich condition. (No oxygen in the exhaust).
In your second video you mention starting out at 3-4 volts. However, I never saw higher than 1 volt on the meter in the video. 0 volts is normal at idle, when the TPS idle switch is closed. Going back and forth between 0 and 1 volt indicates the ECU is trying to compensate for a rich condition.

Looks like you're still running rich.