'DE bogging has returned, Arghh! / Reasons for running lean?

[slipnfall]

The last two graphs simply show that the hesitation/bucking is *there*, but it's just not noticable as it was in the first few(top of thread). The bucking when I first start out is very hard to miss. There's no mistaking it's there.

[Magnes]

[BACKPEDAL]Actually I have to say that RPM trace on the first graph is pretty nasty looking. I'm just saying don't read too much into the speed trace.[/BACKPEDAL]

In any case, your symptoms suggest that the EGR is not being closed by the ECU. I'm a little perplexed about the EGR trace, as the voltage signal to the EGR solenoid should switch between 5V (open) and 12V (closed), but the graph rates it at 5 and 30.

My car exhibits the same behaviour as yours, because the PCM is switching between 1-5 volts instead of 5-12, so the EGR is 'always open'. If your signal is switching between 5-12 then your only problem could be a stuck solenoid. Mine was stuck, but replacing it didn't correct the fact that my computer was sending the wrong signal voltage.

[s13sr20chris]

5 an 12v? i think its 0 and 12v. nevertheless, the bpt and ported vacuum will still keep the egr from flowing.

[slipnfall]

The CONSULT data I receive from my software reports EGR as ON or OFF. To translate that to a graph, I represent ON with 30, and ONwith a significantly lower value. This just makes viewing when it switches on the graph easier.

And yes as I understand it, the BPT can not route vacuum to the EGR unless the ECM-controlled solonoid is open(it's source of vacuum).

[slipnfall]

Magnes, I see what you're saying about the speed resolution. I guess since the other sensors were that precise I assumed the speed sensor to be the same. So you are right in saying that the bumps in MPH are unlikely a result of the bucking itself... however the movement is enough to snap my neck back and forth.

I'm really getting steamed: it seems every time I make the effort to datalog it, it doesn't act up. When I don't have it logging, it's horrible. Just last night I pulled my car into the garage, after it had been parked for 8-9hrs. About an hour later I pull it out, and it's bucking all over the place.

I'm starting to notice it at highway speeds now(55-65mph). It doesn't buck back and forth like in 1-2nd, but it just looses power for a second, then picks right back up. Both this morning and tonight after work I let it run for ~5mins, then logged the data. Nothing seems out of the ordinary. At idle though my timing is bouncing from 18-23*. AAC valve?

I'll continue logging untill I can get a solid example..

Thanks for sticking in there w/me folks.Jamie

[NISTECH]

You gotta get that cap and rotor on there. I am very curious if that will offer you some relief from this. I am guessing you can sweep check the O2 with the graph ?

[slipnfall]

For whatever reason I still have the original rotor that I replaced, an OEM one. The plug wire contact is worn 'down to the bone', but of interest is there is *no* white markings on it. The one that's in there, with roughly, eh, 9-10k on it, is a very different story. I'll snap some pics once the new one comes in...(I should have had MidwayParts ship incomplete).

When you say sweep, you just mean a recording of the A/F(Alpha) and Base readings over time? In that case yes. The logging mechanism I have has a resolution of 48mS(the same HH:MM:SS shows up 21 times in the log, so 1/21=47.6mS), for an infinate amount of time(limited by laptop hard-drive space).

[NISTECH]

No I mean the O2's actual voltage sweeps. [watching the O2 sensor signal voltage]

[slipnfall]

That's what I thought you meant. The honest answer is, I don't know. According to: http://www.plmsdevelopments.co...2.pdf (this is a description of all the commands a CONSULT-I ECU will respond to), there is:LH O2 Sensor Voltage (in mV)RH O2 Sensor Voltage (in mV)A/F Alpha-LH (in %)A/F Alpha-RH (in %)A/F Alpha-LH(self-learn) (in %)A/F Alpha-RH(self-learn) (in %)

and (no units given for the below four:)

FR O2 Heater-B1 FR O2-Heater-B2RR O2 Sensor VoltageRR O2 Sensor-B2 Voltage

I'm just guessing here, but LH/RH for RB(6-cyl in-line) engines(cat on left/right side?)FR/RR for front/rear of catalytic for DE's

I'll have to write a small script to log the specefic commands I want, rather than what this logging software will let me(it's not explicitly implied which commands they are sending).

[NISTECH]

The first 2 you listed are the o2 signal voltages. RH O2 and LH O2.

No you say rb which is an inline 6 cyl. It has no rh manifold if the intake and exhust manifolds are stacked like the old L2x engines were. Now I dont know if they are using 2 pre cat O2's on this engine. Its possible as they did it with the 4 cyl USDM B15 CA model. Does the RB have 2 seperate chambered manifolds on it? I am not that familier with that engine. I initially thought you were working on a KA.

[slipnfall]

Yes I am working with a KA, and I really have no idea about the inline 6 RB either. I thought maybe since they were a 6-cly, they had dual-exit exhaust, and a cat on each side of the car.

[NISTECH]

Gotcha. I think that site is reffering to a V engine when reffering to O2's.

[slipnfall]

I just received confirmation that the Oxygen on the graph above is the actuall O2 voltage, in mV. Is 100mV(the max I see) typical?

[NISTECH]

I am guessing your are reffering to the blue line in your second set of graphs in the second picture. Atthe point between 4341 and 4376 you had a sharp short drop in the signal which came back very quickly and again a less severe one right at 4376. My guess is that at those points is when you felt a slight buck in the car. If so tht indicates a misfire as the cause of your bucking. I would relly like to see that graph when your car is going ape****.

[slipnfall]

lol. Yeah I'v been logging every day to and from work(for the first 10mins or so anyways). I want to try to catch it right when I start out(they get 'lost' when the logging goes on for too long, b/c I forget when they occur), so that I can definitively point and say "there, see!".

I'll post back when I get my parts or a good log, whichever is first.

BTW what is the deal with the Italian distributor caps anyways?

[NISTECH]

poor quality plastic. The plastic is too thin around the electrodes or has to much air in it when its poored cuasing it to crack prematurly. Also the carbon tracking will build up in that plastic quicker. I have seen them out of the box arching erratically.

[Magnes]

Is 100mV(the max I see) typical?

Max is 1V, normal range is 0.1-0.9V.

[slipnfall]

I'm trying to get ahold of the author of the logging software. According to the protocol spec's, the value returned from the ECU is:

LH O2 Sensor Voltage Single byte 0x09 Value * 10 (mV)

So perhaps he/she simply forgot to multiply it by the 10 factor.

Thanks for the clarification.Jamie

[InsanityInc]

Is your TPS adjusted correctly? My car bucks like crazy if it's off by even .05v. Adjust it using the voltage between the two terminals listed in the FSM, not the resistance. I never got it right by setting by the resistance.

[slipnfall]

Yeah, thanks for the suggestion though. I use the consult interface to adjust it, so I know that's *exactly* what the ECU is registering it as.

I know where you're coming from though: mine was sitting at 0.7V for the longest time, and it drove like sheit.

[InsanityInc]

I *really* wish I could afford a consult. One of those would be really, really nice to have.

[NISTECH]

Max is 1V, normal range is 0.1-0.9V.

The minimum range is 0.00volts the max is as said 1volt.

[NISTECH]

I *really* wish I could afford a consult. One of those would be really, really nice to have.

There is consult interface equipment all over the net. Some replicates some of its functions. Most of it is reasonably cheap. Although the consultII is one bad *** handheld for nissans. I dont think there is anything out there to come close to it. In june of next year we are getting the next revolution scan tool. Consult will be a thing of the past. It will be lapo top based and wire less. I will be able to check codes on the car from my tool box

[Bosrudorfer]

I have no clue as to what you guys are talking about but it sounds fun LOL

[slipnfall]

Oh yum.

So does this mean dealers may be selling off their old CONSULT-I/II equipment to make way for the upgrades? Or do they just return those to headquarters for a credit towards the new ones?

[NISTECH]

Oh yum.

So does this mean dealers may be selling off their old CONSULT-I/II equipment to make way for the upgrades? Or do they just return those to headquarters for a credit towards the new ones?

No the consult I/II will stay at the dealers and still be used on the previous models but the new one will work on cars back to 96 [all OBDII] The consultII when it came out in 99 it was retroconnectable meaning it worked on all cars consult I did. So we will continue to use them in the dealer. We have 1 consult I unit [which I got working again the other day after being dead for almost 4 months.] We have 2 consultII units, and we will be getting 2 of the new ones. Since I am a nissan master tech I can have my own asist with all the electronic service manuals[ 94 to present all nissan and infiniti vehicles] for my own personal use if I want it. I dont know if they will offer the bluetooth scan tools software for us when that is put into action. Since I will have my own lap top with all the asist software and ESM's I dont see why they wouldnt give us the scan tool software.

[Magnes]

Why is it that my '89 has a diagnostic connector that doesn't seem to fit anything available? It's sure not the same one as is found on other pre-OBDII Nissans. Is there any method to connect to these "old OLD" connectors, and is there any value in doing so?

... not hijacking the thread, just bumping it up :-)

[NISTECH]

OH yea forgot about that one. That is the 5 mode or checker box connector. We have that too. It is old school, its not a scan tool or anything like that. it is for a box with a switch on it that switches the car between diagnostic modes. You do the same thing with the screw in the side of the ECM. Not worth trying to adapt anything to it all it does is flash 2 leds, there is no data stream in it.

[Magnes]

That is the 5 mode or checker box connector.

Aha!

Thanks NISTECH, I looked it up and will be making my own checker box using the guidance of this site:http://www.teapot.worldonline....x.htmI expect my connections will be a little different, but knowing how it works is the big thing.

Anyways, it's posted now for anyone else who wishes they kew about this 5 years ago!

[Magnes]

Keep us posted on how things are going, I'm interested to know the conclusion. You should have your distributor cap by now.

Also I'd like you to try a little test. I suspect your EGR is malfunctioning (though it wouldn't explain all your symptoms, just the cold start bogging). The next time you go to drive from cold, unplug any one of the two vacuum lines to the BPT valve. This will force the EGR to remain closed (which it should be during cold-engine operation anyways).

Let us know the results.

EDIT:I just looked into the 2nd part of your topic (running lean). The graphs you posted show you were running RICH, not lean. This is normal for full-throttle operation like you would see during a dyno pull, so there is no A/F issue there.
Modified by Magnes at 11:55 AM 11/22/2005