Got my usb aldl cable. What now? *EDIT-NEW heated o2 data is up!!!.*

[y5mgisi]

That was with the new motor. Not that it makes any difference, but they are new "z28" valve springs. They were supposed to be ideal for the cam. I havent yet ran it or turned it over with the valve covers off to watch the lobes. also not that it makes alot of difference but it still goes down the road like "normal". I will hook the white wire to ground then also.

 

[y5mgisi]

I would really like to swap a stock cam back in itbut with the compression numbers that the motor produced i dont really wanna do a whole lot of actual motor work to this motor. I just want it run reasonably well for the next couple years. but if it takes a cam to that i would do it.

 

[magik235]

Have you disconnected your battery lately to reset the computer and clear old error codes?

 

[y5mgisi]

Yea, every time i park it i disconect it.

So, I installed the heated o2. MAde a significant difference! Will post the log in couple minutes.

 

[y5mgisi]

the new log with the heated o2. See the difference?

 

[4X4HIGH]

Yea, every time i park it i disconect it.

So, I installed the heated o2. MAde a significant difference! Will post the log in couple minutes.

You do realize there is a short term memory in the ECM and everytime you disconnect the battery is has to relearn and that can take 40-50 miles of driving.

 

[y5mgisi]

I guesss i should say, kinda? I knew that it had to relearn but i thought it did it much faster then that. I will leave it connected now for as long as possible. I will also get a temporary permit on it so that i can drive it on the road a bit.

 

[y5mgisi]

Also just realized that i need to bump my tiiming back down. I had it up around 9-10 just to get it to run as well as it did, but now that its running better i need to drop it back down. see how that does. and also re set my minimum air.

 

[y5mgisi]

Also, my fuel pressure is right about 11psi.

 

[Russell]

Alright, that oxygen sensor is working nicely now! It is telling the PCM that it is crazy rich now, and the BLMs are responding as they should by cutting the fuel down as much as the engine is capable of by dropping to 105. Your vaccum is still reading quite low at about 45 kPa, where it should be closer to 75 kPa.


So, since it isn't the computer's fault, since it has recognized the problem and is doing all it can to correct it, that leaves you needing to troubleshoot your fuel system with more scruitny. Only thing that can make your mixture that rich is either too much fuel pressure or bad injectors.

Once again, I would highly reccomend spending the $50 on a fuel pressure gauge kit for your TBI engine to see where you are at. You should have 11 - 14 PSI of fuel pressure on the inlet side of your engine. Make sure you don't measure the outlet side, as it should technically read next to no fuel pressure, being that the downstream side dumps straight into the fuel tank.

If your fuel pressure is good, you need to take a few minutes with your timing light and take a look at your injector spray pattern. It should be a nice clean spray pattern without any dribbles. The spray should hit the walls of the throttle body just above the butterfly valves. A little bit of dribbling on the walls of the throttle body is normal, but it should not be dribbling out of the injectors themselves. Also make sure that your injectors are infact pulsating and not running static by hooking up a noid light to one of them. It should flash, not stay on steady. You can use a marker light in place of a noid light if you want, but it will not flash, but rather should pulsate in intensity instead.

If your injector pattern looks good, pop the wiring off the top, and take a look at the color pattern on it. It should be orange on one side, and black on the other. If they are yellow and brown, blue and black or red and blue, you have high flow injectors which will not work with your engine without re-programming.

If your fuel system is all up to spec, then you need to start looking into getting some programming done to make the base programming fit your engine a bit better. Based on how your engine has been responding in the data logging, the camshaft probably is going to work alright with your engine. Typically the camshaft would cause the engine to see a lean condition, similar to what you had before, not a rich engine like is being reported now.

 

[y5mgisi]

Ok, correct me if im wrong, but i thought that i was reading around 35 ish kpa on the map which i THINK is supposed to be around 20inhg? when i have the key on but not running the map reads 101kpa. That being the case i have deduced that the higher the kpa, the lower the vacuum. Correct? I was pretty happy with the vacuum readings. should i not be? I had a fuel pressure gauge on during the run today and it stayed right at 11psi the whole time. I will watch the spray pattrn and see where it lands but it seems to have a very apporpriate spray and nice cone shape. i will also make sure that i dont have the high flows.

 

[y5mgisi]

Tell ya what else i will do is put a vacuum gauge on there to see what the motor is actually seeing.

 

[Russell]

Very good idea! Make sure you hook it up to a full manifold vaccum port when you do. If you've got 20" of vaccum, then your truck's motor is set up mechanically pretty much perfectly. All that would be left in that case is simply that you need to have a chip burnt to match what you've got.

That said, 101.325 kPa is the theoretical atmospheric pressure at sea level, which you are very close to being in Portland. When you first start your truck, and when you shut it off, the ECM uses the MAP sensor to measure barometric pressure, so it should read something close to that, which it does. When the engine runs, it sucks against the butterfly valves causing the overall pressure within the intake to drop as compared to atmospheric pressure, so the value should drop.

The MAP sensor does not read the actual absolute pressure within the intake, but rather the difference in pressure between the reference (atmosphere) and the measured value (intake pressure), aka, a gauge pressure.

Keeping in mind that in mind, you want about a 20 - 22 "hg difference between the pressure in the intake manifold at idle as compared to atmospheric pressure. 22 "hg = approx 75 kPa. So, the MAP sensor should be showing around 75 kPa at idle.

If you have a big difference between a known good mechanical pressure gauge reading and the MAP reading, the MAP sensor must be changed. It too can cause all the issues you are seeing if it has a leak on it's sample line, or if the MAP sensor itself is leaking.

Take a look at this chart:

 

[y5mgisi]

I had found this thread that said i was ok. I forget why but i was under the impressin that basically the map reads"backward of what it should" On a gauge.

http://www.thirdgen.org/techboard/tbi/305486-question-map-sensor.html


And in this thread a guy says,

Idle MAP values are nice = 36 KPA is about 16 to 18 in-Hg

http://www.thirdgen.org/techboard/tbi/581893-winaldl-data-help-tbi.html

 

[y5mgisi]

My thoughts were that because it read 101 with key on, engine not running, the further away from 101 that it got(the closer to zero that it got) then the higher the vacuum. Is that logic skewed? In other words, 101 equals zero vacuum, therefore near zero must equal lots of vacuum.

 

[Russell]

Well, it looks like my previous understanding on the MAP sensor's operation must have been wrong! Those guys on thirdgen.org know their stuff, and if something was posted falsely, someone would have chimed in to correct it.

Let me do some better research and I'll get back to you! I have never really dealt with MAP sensors much, pretty much have always just worked for me, haha

 

[Russell]

Ok, read up on it, and you are right! 35 - 45 kPa winALDL reading is normal. I think that if your fuel system is all good, you simply need a chip now.

 

[y5mgisi]

Russel, believe me it warped my mind something fierce! I went to all these in.hg. to kpa conversion sites and even looked at that map explanation pic you posted thinking that i was all out of whack. Then come to find out, that it was actually correct. Here is what gets my brain twisted,

take the kpa reading on winaldl and convert it to ingh. its like 10 inhg. now look over at the vacuum gauge attached to the manifold, its 20 ingh! Search on the web and find that others are getting the exact same results and confusion that i am!

That tangled my mind up for a while until i just accepted the fact that thats the way it is. I now think of it like this, the further from 101kpa(atmospheric pressure), the more vacuum its producing. Or in yet other words, the the smaller the kpa, the smaller the pressure.

When this all started i think i was thinking how you were. Which turns out to be fundamentally correct until you start adding in the fact that a computer is running off a sensor designed to tell it specific information.

 

[y5mgisi]

here is acouple more loggs from today. actually drove it up and down the street in one of them.

 

[y5mgisi]

Couple new ones from today. The truck does run very very much better, funny thing is, it runs about the same as before it started running rough at idle all the time... Now it just surges in gear at idle... Took a couple vids too. i'll get them up on youtube and then post them up.