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240 '89 244 lh2.4 2-3-2

A plug chop sounds dangerous to do under boost... or while driving at all... I have a multi-meter from Harbour Freight. It does just Dandy.
 
volvoboy90 said:
A plug chop sounds dangerous to do under boost... or while driving at all... I have a multi-meter from Harbour Freight. It does just Dandy.
Click to expand...

Most likely too slow a response to pick up the O2 sensor sine wave output. My $30 Sears DVM cannot, but my $130 Radio Shack (Fluke) can, something under 10 ms response should work. Here's where a DVM with a min-max storage helps a lot, too.
 
volvoboy90 said:
A plug chop sounds dangerous to do under boost... or while driving at all... I have a multi-meter from Harbour Freight. It does just Dandy.
Click to expand...

so what happens when your engine dies whilst driving
(the lights come on the engine stops you push in the clutch
and drift to the side of the road...)

the only diff here is that YOU are gonna cut the engine off...
I do this on Bikes ALL THE TIME and I ain't dead yet...

of course I also do this in DYNO CELLS but you haven't told us
(yet) that you have a dyno (and I would drive to see your dyno if
ya get one...I wanna run my ground piercing radar rig over Wright
Patterson so I can "see" *ALL* of the levels below...hee hee....:cool:
 
Hehe... no, no dyno... Just a two car garage you can't fit a single car into. That's one thing as well, she is an Auto-Majic. So shift into Neutral, or just turn the key and let her coast? Just so I get my facts straight. We got a cold front moving through tonight, making freezing highs for all next week, so checking the sweep of the Wideband may take some time, and I won't really be able to do much of a plug chop either... Hrmmm....
 
One thing I just noticed after you saying the WB would need warm-up, next time you install one, do it much closer to the ex outlet at the manifold. That way you get more accurate numbers about what you're engine is doing, since the hot ex gases do the warm-up for you, unlike the O2 sensor down the header pipe near/in the cat, which is heated.

You can probably disregard the numbers from the WB unless you've driven it for ~15-20 min, and be stepping on it to get the WG to stay open so the ex gases heat the sensor.

The most accurate placement for the O2 sensor (WB) for engine management (think B21FT and K-Jet) is in the ex manifold itself. A lot of people don't consider this when doing the +90 manifold, the engine management comes from O2 sensor feedback not a fuel map like LH xxx. and on LH the O2 sensor is there for emissions fuel trim and does little for engine management. Does little for WB accurate a/f measurement.

Your WB needs to see that same kind of info as does the K-Jet O2 sensor.
 
Aye, I didn't think of it when I had the original Narrow-band put in, and just figured "by the original" would be fine. Unfortunately, too, my commute in the morning is 15-20 minutes. If I ever have to replace that downpipe, I don't know what I'll do, since it was pretty much a one-time shot. It is half original Starla down-pipe, half custom downpipe from a friend. Noticed today, it is taking longer to crank on start-up than usual...
 
Here is a quick question. As far as the wire I am using to measure the sweep, will it be the wire that "would" be going to the fuel injection if I had it hooked up that way, or is there a certain wire going to the meter itself I should use? This cold weather is stunting my progress, had some snow come down, and it has been freezing all day. The prolonged cranking has stopped, at least.
 
Yep... If I can get this fuel trim issue gone for good, and be rid of that annoying sound in the rear, I will be golden. :cool:
 
So I tested the o2 sensor today... not the wideband, haven't had a chance to pull it from my dash to change the position on it. From what I could tell, it did read sluggishly, taking a second or two to register vac leaks, and running rich. When I did the dynamic testing, it was at both extremes of the fuel map, going as rich as .8 and then to as lean as .1 but never really getting close, or staying near .5.
 
volvoboy90 said:
So I tested the o2 sensor today... not the wideband, haven't had a chance to pull it from my dash to change the position on it. From what I could tell, it did read sluggishly, taking a second or two to register vac leaks, and running rich. When I did the dynamic testing, it was at both extremes of the fuel map, going as rich as .8 and then to as lean as .1 but never really getting close, or staying near .5.
Click to expand...

you're OK.....it's the SWEEP that is important (and your measurements prove the sensor to be "reacting CORRECTLY* to the mix in the exhaust gasses)...hmmmm....if the meter reads an S-L-O-W "shift from 0.1 to 0.8 Volts (this is ASSuming I understand your observations)...SPEC is 1Hz "sweep"
I notice you point out the "sluggish response to an artificially created vacuum leak"... it *could be* just a lazy sensor but the numbers you've provided indicate the "system" IS going into closed loop....

here is a decent screed on the subject of "testing the O2 sensor":
http://www.autodiagnosticsandpublishing.com/feature/o2-sensor-testing.htm
 
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So you think it's OK? I read a little of that article, haven't had much of a chance. Not really sure where to go from here. I did talk to my friend jc, he said the lack of vacuum in gear could possibly be the cam. After some maths, I found I am still getting ~17mpg.
 
Now obviously, my multimeter cannot test several times a second. I mean, it is decently quick, but not that quick. I did tighten down an exhaust leak yesterday, just for the sake of it, really. It was too far downstream to affect the afr's. I really am just stumped. No vacuum canister to leak, no hvac system to be leaking. it is just a closed system with the PCV, boost gauge, FPR, IAC, brake booster, and the whole intercooler piping being any issues for vacuum leaks. Idle still maintains at ~500 RPM. I have clamps or zip-ties on all vacuum piping. :e-shrug: I am just really... stumped.
 
volvoboy90 said:
So you think it's OK? I read a little of that article, haven't had much of a chance. Not really sure where to go from here. I did talk to my friend jc, he said the lack of vacuum in gear could possibly be the cam. After some maths, I found I am still getting ~17mpg.
Click to expand...

17 mpg in a TURBO CAR (that you can "FEEL the EXCITEMENT
shove you back in the seat")...is THAT what's botherin' ya??
DAHUM man....I have a "warmed over B230f" *N/A* that I get 24
to 26 mpg if I play NICE and 20-22 mpg if I go all hooligan on the
two lane blacktop....

*PICK YER POISON*...either put a raw egg under your gas pedal
and tip-toe around town - *OR* learn to live with the GREAT FUN of
sucking unsuspecting "other brand drivers" into the educational benefits
of NEVER underestimating a "grandpa car" again....hee, hee....

I just inherited a 1989 245 (M47...etc) that is gonna have to stand in for
the 1993 "Special Edition 245" that I REALLY wanted to use as the basis
for a sleeper deluxe....(LSx and T5....cranked suspension and meaty boy
tyres)....the "ultimate DRAGON WAGON" (at least for me)....coming to a
high road near you in late 2014....in basic white and no "outward signals"
that it hath a HUGE heart....my final "car project" as I'm starting to get
"cripped up" due to advancing arthur-itis ("Is that damned Greek here again...?? :lol:)

carry on old son...carry on.....
 
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