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ZUKIWORLD Discussion Forum => Technical Discussion - Beginner / Repair => Topic started by: mbruce on June 10, 2011, 06:47:04 PM

Title: Removing O2 sensor
Post by: mbruce on June 10, 2011, 06:47:04 PM
So what's the secret behind removing the O2 sensor screwed into my rusted exhaust manifold?

PB and Knock-R-Loose has not phased it....I'm out of ideas and i dont want to bring out the breaker bar in fear that I will break something.
Title: Re: Removing O2 sensor
Post by: wildgoody on June 10, 2011, 07:26:12 PM
I had to weld a new nut to the top of the manifold when I
took mine out, and then I found out it didn't need changing

Why do you want to change it? running bad/rich or just because?

Wild
Title: Re: Removing O2 sensor
Post by: mbruce on June 10, 2011, 07:53:13 PM
It may not need changing...it's 21yrs old and looked like an easy change...I was wrong!

It may be just fine...the engine is not running well... Doesn't respond well to the throttle lever ...sputters then backfires out of the air intake manifold. Can't adjust the TPS to the book because the throttle lever never touches the stop screw so can't use the .012 or any other specified feeler. It ran better before I started an endless pursuit to figure out the "cold idle" that has "dead spots" in throttle response before it's warm. I've replaced the AIT and CIT... I did have a 4:4 check engine light which is TPS adjustment...the check engine light isn't on anymore but it should be! new plugs and wires...I can pull a wire on each plug and the engine responds as it should...guess it's an air problem ?? It's fuel injected

Have you heard a backfire at the intake manifold before?
Title: Re: Removing O2 sensor
Post by: wildgoody on June 10, 2011, 11:31:39 PM
I have a bad TPS, it doesn't cause flat spots, it causes an off
idle dead spot like no accelerator pump, I even removed the
TPS and it runs ok, just that flat spot.

The 8V TPS is more of a switch to tell the ECM the throttle position
off idle and WOT, but it isn't a linear resistance like most TPS sensors.

I would look at the MAP sensor and any blockages in the hose leading
to it, or holes/breaks in that hose.

Have you checked the timing and firing order? 1,3,4,2, rotation clockwise,
timing set about 8* BTDC your truck may vary but it should be good enough
to run right

Wild
Title: Re: Removing O2 sensor
Post by: mbruce on June 11, 2011, 05:37:27 AM
Alright so I found the MAP...and when the hose is disconnected from the manifold it runs like a champ...smooth and revs perfectly to my un-trained ears.... when the hose is connected to to the MAP it sputters and backfires everytime and all the time.   I can put my finger on the hole on the manifold where the MAP hose goes and it does slow down idle but idles and revs like a champ.  so -- do I even need a MAP sensor?  Is this a sign that the MAP sensor is bad and should be replaced or is this a sign that points to another problem? I didn't connect the (3) 1.5v batteris and a Volt meter and vacuum guage and test it that way -- I can if needed ?? This is awesome though -- can't beleive it's that. And the hose is not stopped up. it's a $300 part (depends on where you look -- Rockauto.com has it for $85 but they have a weird website) but the sammy can run again -- well if that's really the problem.

Should I have a Tracker MAP sensor or a Samurai MAP sensor?  There are generic MAP sensors at Autozone but you have to know how many "bars" you need.  They have sensors from 1 to 5 bars....

The timing is set to where it's always been set according to the mark on the bolt (doesn't mean its right ) and i'll have to leave it be  since im missing my belt cover with the number guide... it's ordered though.  Only 9 more days until it arrives...LOL

 
Title: Re: Removing O2 sensor
Post by: wildgoody on June 11, 2011, 09:42:12 AM
Well it could be bad, but I wouldn't buy a new one, you should be able to get
a used wrecking yard one cheep for testing and replacement

The fact that when you pulled the hose from it and the engine runs better
kind of shows that it is working, but it could be out of spec

When you pull the hose it sends a need more fuel or enrichment to the
ECM, (low vacuum) and it responds with more, so you have a lean fuel
condition under normal conditions when it's connected, that is your real
problem, when I disconnect my MAP my engine runs rough and sputters,
because it's too rich.

Try pulling the O2 sensor wire and check it for a small current, (engine running and hot)
I think it's in the milivolt range (sensor side wire) or might go to 1/2 V that would tell
you if the O2 is working as it sends a + or - V signal depending on rich or lean exhaust
conditions, and the O2 might be bad and the computer is stuck with a thinking rich because
the O2 is sending a rich signal to the ECM even though the mixture is in fact lean, and you
pulling the MAP hose is fixing this lean condition

Wild
Title: Re: Removing O2 sensor
Post by: mbruce on June 11, 2011, 05:45:01 PM
finally got the O2 sensor off and replaced it.   For about 4 mins the engine ran smooth and as it should with the MAP hose connected to the motor... I took the map hose off the motor and it ran worse... so i was like yea the o2 sensor really was it --  Then after 4 minutes it ran like crud missing and backfiring with the hose on the motor...so unplugged the MAP hose from the motor and it ran "as it should".....grrr!!  >:(

I dunno -- my cousin is talking like it could be a burnt valve(s). But my cylinder compression is 180psi x 4 and it jumped to 180 by the 3rd turnover in each valve.  I hope its just a MAP sensor issue or even better a cheaper sensor!  I can test the MAP sensor like in the books... (3 1.5v batteries, a volt meter, and a vacuum.... ) if that will help

tomorrow he's bringing his diagnostics computer over and going to run code....

And the timing may still be off -- no way of really knowing until I get the timing cover with the numbers on there.... so im keeping my fingers crossed.
Title: Re: Removing O2 sensor
Post by: wildgoody on June 11, 2011, 06:45:23 PM
Well it would take about 4 min for the O2 to get hot enough to work,
so back looking at the MAP as a problem, go ahead and test out the
MAP to see if it's out of spec, I don't think you need to throw in timing
to the mix as well as everything else that's going on, eliminate 1 thing
at a time so you know when there is a problem with what you did

Wild
Title: Re: Removing O2 sensor
Post by: mbruce on June 11, 2011, 07:17:51 PM
K will do. I was doing cartwheels for the first 4mins...lol.

Do you know where the diagnostics plug-in is on a 90' Samurai. We looked and couldn't find it...is it on the ECM ?
Title: Re: Removing O2 sensor
Post by: wildgoody on June 11, 2011, 08:22:29 PM
On my 89 Kick it's over by the battery, and you just use a paper clip to get the CEL to flash codes
Title: Re: Removing O2 sensor
Post by: mbruce on June 11, 2011, 08:31:39 PM
Crummy i have no codes! I have a white connector pin looking thing by my battery...that may be it!
Title: Re: Removing O2 sensor
Post by: wildgoody on June 11, 2011, 08:35:02 PM
Codes don't just flash up, they need to be coaxed with by shorting the diagnostic terminals

I think it is a 4 pin plug, and should of had a cover on it to keep dirt out
Title: Re: Removing O2 sensor
Post by: mbruce on June 11, 2011, 09:15:51 PM
Right now I get codes by putting a  yellow 20 fuse in the lower right slot.... unfortunately i'm getting 1:2..... which is everthing is OK!

There is a way to get more codes from an ODB1 other than the fuse in the fuse box?
Title: Re: Removing O2 sensor
Post by: mbruce on June 11, 2011, 09:46:32 PM
Found it!  Let's hope the fancy dignostics computer picks up codes that aren't flashing on the CEL
Title: Re: Removing O2 sensor
Post by: wildgoody on June 11, 2011, 10:35:00 PM
 :) That's what I was thinking of, my truck isn't at my house so I have to go from memory
Title: Re: Removing O2 sensor
Post by: mbruce on June 12, 2011, 08:33:04 AM
Title: Re: Removing O2 sensor
Post by: Rhinoman on June 12, 2011, 09:08:28 AM
The 8V TPS is more of a switch to tell the ECM the throttle position
off idle and WOT, but it isn't a linear resistance like most TPS sensors.
Wild

A 90 might have the TPS switch but 91 on have a real TPS.
Title: Re: Removing O2 sensor
Post by: Rhinoman on June 12, 2011, 09:15:24 AM
The MAP sensor measures absolute pressure which will be high with key off and then drop with load. Vacuum is a relative measurement and will increase with load. Key on engine not running you should read atmospheric pressure which is around 1 bar or  around 29.5in/Hg. For a real FSM (albeit for later models) try here:

http://www.suzukiinfo.com (http://www.suzukiinfo.com)
Title: Re: Removing O2 sensor
Post by: wildgoody on June 12, 2011, 09:30:02 AM
The range they give is quite wide, but your findings are or appear quite linear
in the results, so I would say the MAP is working as it should.

The range that would be in question should be from low vacuum like 1 to 2 in
and high at about the 15-16 in range, outside of that you don't really need as
your engine will not be producing power at those levels, over 15-16 is a deceleration
condition, no fuel needed, and below 1-2 would be either engine not running (NA) or turbo
boost which you don't have.

Normal WOT vacuum is low but never 0 on a NA engine


The only other thing I can think of is your fuel pressure and or the injector might
be plugged somehow, fuel pressure on an 8V is lower than on the 16V about 34 PSI
at the fuel line on the back side of the TBI, kind of a pain to test, I had to cut my fuel
line and add a "T" fitting to get a reading. I don't know what the manual says to do
to check it, but somehow you are still getting a lean condition, because when you pull
the MAP vacuum line it tells the ECM more fuel, and your truck runs better

Good work so far
Wild
Title: Re: Removing O2 sensor
Post by: fordem on June 12, 2011, 09:47:11 AM
I don't know what the manual says to do to check it, but somehow you are still getting a lean condition, because when you pull
the MAP vacuum line it tells the ECM more fuel
, and your truck runs better

Good work so far
Wild

Are you sure about that?  It seems to be the reverse of the what I would expect.

A high vacuum on the MAP sensor would indicate a closed throttle, and as the throttle opens the vacuum decreases (gets closer to atmospheric pressure) - I'm not sure about the Samurai EFI but on the aftermarket systems I've worked with the MAP line is primarily used to sense load and vary the ignition timing to suit (retard on low vac, advance on high)
Title: Re: Removing O2 sensor
Post by: mbruce on June 12, 2011, 09:53:55 AM
K I will check fuel pressures. I'll head to autozone to rent the tool.

I never thought to mention but I did add a bottle of SeaFoam injector cleaning to the tank of gas...the bottle was for 12-20 gals...so I just poured in all of it. The bottle directions said it was ok...did it possibly dilute my fuel?? That even possible with those injector cleaners?
Title: Re: Removing O2 sensor
Post by: wildgoody on June 12, 2011, 10:22:07 AM
I don't know what the manual says to do to check it, but somehow you are still getting a lean condition, because when you pull
the MAP vacuum line it tells the ECM more fuel
, and your truck runs better

Good work so far
Wild

Are you sure about that?  It seems to be the reverse of the what I would expect.

A high vacuum on the MAP sensor would indicate a closed throttle, and as the throttle opens the vacuum decreases (gets closer to atmospheric pressure) - I'm not sure about the Samurai EFI but on the aftermarket systems I've worked with the MAP line is primarily used to sense load and vary the ignition timing to suit (retard on low vac, advance on high)

Ya, and you just said the same thing I did.

If you pull the vacuum line from the MAP is reads atmospheric pressure, similar to WOT  ;)
Title: Re: Removing O2 sensor
Post by: wildgoody on June 12, 2011, 10:27:47 AM
K I will check fuel pressures. I'll head to autozone to rent the tool.

I never thought to mention but I did add a bottle of SeaFoam injector cleaning to the tank of gas...the bottle was for 12-20 gals...so I just poured in all of it. The bottle directions said it was ok...did it possibly dilute my fuel?? That even possible with those injector cleaners?

I don't think that Seafoam would cause the problem, but if the tank was full of gunk, it may of sent it to the
fuel filter or be clogging the sock on the fuel pump in the tank.

Pressure will tell you if that is the problem, but changing the filter is never a bad idea
Title: Re: Removing O2 sensor
Post by: mbruce on June 12, 2011, 11:22:43 AM
Has the TPS been ruled out? I can't really adjust it to spec because my throttle lever stop screw is not in use at it's current setting...I forgot about the TPS...before I had a TPS adjustment CEL...I adjusted it with the ohm meter but without the .012 feeler and the CEL went away.

The fuel pressure test kit is quite large...I'm about to read how then test it

Thank you for all of your input!!!
Title: Re: Removing O2 sensor
Post by: wildgoody on June 12, 2011, 11:38:56 AM
I don't think it's ruled out, but the truck runs good when it gets enriched
so I think it's OK, what year is the truck again ? 
Title: Re: Removing O2 sensor
Post by: mbruce on June 12, 2011, 11:40:48 AM
1990
Title: Re: Removing O2 sensor
Post by: fordem on June 12, 2011, 11:49:23 AM

Ya, and you just said the same thing I did.

If you pull the vacuum line from the MAP is reads atmospheric pressure, similar to WOT  ;)

Aahh - pull the vacuum line = disconnect it, not pull a vaccum on it - my bad.
Title: Re: Removing O2 sensor
Post by: mbruce on June 12, 2011, 01:27:32 PM
I'll have to see my options before doing the fuel pressure test. None of the adaptors in the kit will work...there is a T splice but not sure if cutting my hose is the way to go without a replacement hose...I'll go look around the parts store and see if there is a t made for this purpose
Title: Re: Removing O2 sensor
Post by: wildgoody on June 12, 2011, 04:49:11 PM
All you need is a double barb fitting and 2 clamps to put it back to 1 piece,
been running mine like that for well over 5 years now
Title: Re: Removing O2 sensor
Post by: mbruce on June 12, 2011, 06:50:25 PM
Cool - picked up 3/8 barbs and clamps! I'll break it down tomorrow and see if we're measuring up to specs
Title: Re: Removing O2 sensor
Post by: mbruce on June 12, 2011, 07:52:01 PM
This doesnt have the signs of an electrical problem -- like a short somewhere does it??
Title: Re: Removing O2 sensor
Post by: wildgoody on June 12, 2011, 09:10:28 PM
If a short to earth could cause a lean condition then yes, but I don't
think so, but have you checked the wires for rubbing through ?
Title: Re: Removing O2 sensor
Post by: mbruce on June 13, 2011, 07:54:14 AM
I haven't checked any of the wires.... I checked the volts from ECM to Map sensor connector and it was 5V and middle wire had 3.8V... one of the wires didn't have any volts.

I did take the dash out and put in instrutment panel bulbs that were missing. I also installed a Tach....for the short term i just connected with twist caps and wrapped in electrical tape -- I now have the heat shrink insulation and solder if i need to redo it.  I tied my tach backlight into the headlights (I need to tie it into the dimmer), and ran my power to the battery... I couldn't find a power wire. (I found 3 or 4 wires that had power but when I connected my Tach to them the tach would barely move or didn't move it all... so I just went with the battery b\c it worked.)

Surely that doesn't have anything to do with it?

and I don't remember if it ran like this before the tach install or not... it's all running together -- I need to start writing details down with dates.
Title: Re: Removing O2 sensor
Post by: wildgoody on June 13, 2011, 08:29:59 AM
So you did check the MAP volts, was the MAP test you posted Ohms
or Voltages? The 5 volts you have going to the MAP is the normal 5V
reference signal, but the returning volts to the ECM should fluctuate
with the MAP vacuum signal, have you checked it this way?

I don't know about your other wiring, could be a problem because of the
Japanese way of wiring stuff, most connections will be hot, and a grounding
switch will activate that circuit.

When I added the MegaSquirt I needed a tach signal, and my first attempt
the truck would not start, so I picked another, don't remember what but that
was fine, so you may want to undo your electrical changes before digging too
deep just to find out that was it

What did you use to get a tach signal? you need a ground from the coil usually
along with power and your back light, could be you are causing a problem with
the ECM and the tachometer cutting impulses that the ECM, uses to deliver pulses to
the injector, just a thought

Title: Re: Removing O2 sensor
Post by: mbruce on June 13, 2011, 08:50:18 AM
I tied into the brown negative wire on my coil. The factory had a splice about 4" from the coil so I just unwrapped their blue electrical tape, wrapped my tach  around the open wire, then taped it back...works great! I'll undo it and see if there r any changes.



Title: Re: Removing O2 sensor
Post by: wildgoody on June 13, 2011, 10:27:09 AM
That is where I tied mine in, should be ok
Title: Re: Removing O2 sensor
Post by: mbruce on June 13, 2011, 12:20:22 PM
My fuel injector sprays a nice even umbrella pattern.  The spray stays the same intensity whether the  MAP is plugged in or not...... that may not be normal ?  The "backfire" can clearly  be seen with the air intake removed -- a fire bomb comes up from the throttle body and hits the fuel injector.... if that is a sign of anything --

I looked at my CEL light to see if it wanted to talk to me today -- and of course it didnt...but i noticed my fuel guage is on a 1/2 a tank... I filled it full 2 weeks ago and it's been sitting since -- we idle it and rev it up to tinker and troubleshoot but that's it...  that's crazy that it's burning that much fuel!

I noticed my EGR valve never moves -- according to the book when the engine is cold it should not move -- but once the engine warms and you increase the RPM it should move back and forth or at least move....  I hosed it down with brake cleaner yesterday and removed a lot of the carbon build up so there isn't much there....  
The book said if it doesn't move back and forth then apply vaccuum pressure to see if it moves -- if not replace it -- if it does then leave it be.... but if it doesn't move on its own then how can it be good -- oh well -- book knows more than me. I'll test that tonight.

Will a bad EGR cause issues like mine... I googled EGR symptoms but none were specific enough as "runs great when unplugged from MAP -- backfires, sputters, dies (sometimes) when plugged into MAP. I think my charcoal canister is from the 1800s too....

I'll check fuel pressure after work --

Title: Re: Removing O2 sensor
Post by: Drone637 on June 13, 2011, 06:16:24 PM
I've seen the EGR do some weird things, including make the engine miss and drop a cylinder once the vehicle warms up.

When you squeeze the EGR valve and force it to open does the car die?
Title: Re: Removing O2 sensor
Post by: mbruce on June 13, 2011, 06:42:03 PM
Yea I can apply vacuum to the egr at idle and engine will die

Will the Samurai 1.3L ECM work on the 1.6L/8v?  Or to be done the right way should the 1.6L/8v have the tracker ECM?
Title: Re: Removing O2 sensor
Post by: mbruce on June 13, 2011, 07:52:42 PM
Fuel pressure at idle is 31psi

Title: Re: Removing O2 sensor
Post by: wildgoody on June 13, 2011, 08:55:02 PM
That's a bit low, can you test it under a load? find a hill and do an extended
drive up it or just a little full throttle acceleration, and note the pressure.

Being it's 31 at idle I bet it goes way low under load.

You can check to see if it's the regulator or the fuel pump/filter by pinching
off the return line, it's the little green toned small can thing on the front side
of the TBI, similar to the location of the steel line in on the back side of the
TBI. There is a small vacuum line on the right side and a bigger return on the
left side, pinch it off and check the pressure, doing that might even clear up
to low pressure issue if the regulator is sticking, the OEM fuel pump should
hit about 80 PSI if I remember right

Wild
Title: Re: Removing O2 sensor
Post by: mbruce on June 13, 2011, 11:11:49 PM
I'm way off from 80! When I reved it with the throttle lever I saw it get to 45- 50 -- but not sure how high I reved it.  The book said to just test at idle and if it falls between 24 -30 then it's good.... so i unhooked it and put in my barb -- i can redo the test under a load tomorrow.

Tonight we did a cylinder leak test and there was air coming back up thru the head -- We ensured the valves were closed by unscrewing the valve springs a bit to where they were loose and rockers rocked... I read where 8-15psi of leakage is ok so that tells me that it's normal to have some air come back up thru the head or somewhere ??--  our leak test device didn't have the dial guages so really not sure how much air was coming back up thru the head.

I doublt the issues are related...then again i don't really know much -- but it runs sweet when unplugged from MAP...so i think it's OK engine wise...
Title: Re: Removing O2 sensor
Post by: wildgoody on June 13, 2011, 11:32:42 PM
Your fuel pressure shouldn't fluctuate that much, should stay fairly steady, and
the 80 is with the returned blocked or pinched off, not normal running, you just
want to test the pump and the regulator
Title: Re: Removing O2 sensor
Post by: mbruce on June 14, 2011, 07:37:16 PM
i'll have to wait a few days before I can get another fuel pressure reading.  My head is semi torn down... i dont even know what to call it -- but the rocker nuts are lose and need to be set back to specs. And we took the timing belt off...  ??? ???

My helper was chasing a burnt valve theory...but now he's thinking it's air or electrical.  We're going to do a smoke test on Friday to see if there's any leaks causing the issue....then we're going to electrical issues including the fuel pressure like you mentioned. 

Soon enough we'll have it all covered and will end up doing an engine swap, ECM swap, wiring harness swap... I guess eventually the problem will be tracked down?!?!?
Title: Re: Removing O2 sensor
Post by: Skyhiranger on June 15, 2011, 02:08:10 PM
Will the Samurai 1.3L ECM work on the 1.6L/8v?  Or to be done the right way should the 1.6L/8v have the tracker ECM?

To do it "right", the intake, the wiring and the ECM must all match the engine.  Some people run the 1.3 ECM, wiring and intake on the 1.6.  Sometimes it works ok, sometimes it doesn't.
You can not run a trackick ECM with a 1.3 wiring harness.  Even though the plugs will plug into the trackick ECM, they are pinned out differently and they don't use all the same wires.
Title: Re: Removing O2 sensor
Post by: mbruce on June 17, 2011, 02:42:44 PM
After feedback....I went with a "guaranteed" fix that supplied me with the needed 1.6/8v TBI, ECM, wiring, ignitor parts..... and supplied others with needed parts (if they ever show up and buy them) that helped make this donor vehicle a cost effecitve solution to my electrical/mix-matched liter troubles.  No one can put a price on the yellow teardrop wheels.