Consult Readings - Advice?

[96Qowner]

I've been annoyed by what feels like less power once it warms up, so I replaced the thermostat and had the Nissan guys do a power balance test. I thought I was going to get sheets of readouts, but apparently it just printed out onto a small paper tape. It shows no codes, and these cylinder readings:

#1 Stall#2 Stall#3 Stall#4 Stall#5 126rpm#6 26rpm#7 13rpm#8 44rpm

CMPS-RPM(POS) 968rpmCoolant Temp 81*C

They declared #7 weak, ohmed the injector and found it within range - recommending a BG flush. I didn't have time to chat with them when I picked it up. What's with the stalls on #s 1-4, and the 126rpm reading on #5?

Think I should go for a full flush or just run a can of BG44K through it? I'm due for an oil change, and I put on 110 miles/day on the highway - how many miles does a BG44K treatment require?

[Q45tech]

Never should have a stall!

I expect the plenum and throttle body are very dirty and the IAC improperly set [air bypass screw].

BG 44k won't work miricles it just cleans injector tips and maybe the valve stems and some off the piston crowns.

I use 44k every 3,750 miles [90 days]. Since you drive so much are you getting oil changes every 6 weeks [42 days]? to maximize longevity!

Get TB and plenum cleaned then 44k for a couple of treatments.

[96Qowner]

I'm a bit shocked. I had the plenum job done at T3 less than 20,000 miles ago. I didn't realize things got so dirty so fast.

The Nissan service writer said things were just great yesterday when I picked it up. Big smile - nice young guy, friendly - I suppose since it didn't throw any codes, he thought that was great. I talked to the tech today and he didn't like the stalls either. I'm taking it in tomorrow for a BG system flush. The thing is, the car runs just fine - no sign that the intake path is dirty - steady correct idle, no missing, etc.

They only charged me $92 for the Consult. Maybe I'll have another done after the flush.

As far as oil changes, any reason not to use high-mileage dino oil? 42 days is 4000 miles for me, so, yep.

[Q451990]

Unless something is massively wrong (major blowby) your plenum shouldn't be very dirty yet... Do you see oil consumption or smoke?

As far as the oil changes, I don't see a reason not to use the high mileage oil as long as it's good quality. I think it has valve seal conditioners. I would still prefer seeing a high quality synthetic, but the benefits of switching now may not justify the cost.

Q45Tech... what does the "STALL" result mean on the power balance? I have seen 0RPM before, but never "STALL"

Heath
Modified by Q451990 at 6:24 PM 6/14/2006

[Q45tech]

20,000 miles is enough time to get dirty [but dirt is relative] in that wiping with white gloves is the standard.

Especially when you drive MOST MILES at highway cruise.........egr is the constant 5-8% of incoming air vs city idle/acceleration where there is ZERO egr.

[elwesso]

My guess is that the plenum is yet dirty enoguh to cause any problems.. I took my TB off 2 months ago as my quartly TB clean and plenum inspect and it wasnt that dirty at all... not 100% clean, but not aweful! I have yet to remove the plenum! Was the IAC cleaned? can you tell us all the details from the printout (IAC duty cycle, CMOS RPM, coolant temp, etc).

Dont pay too much for high mileage stuff!

What was the RPM the PBT was done at? Even if it was done at IDLE it shoudl NEVER stall!

Stall simply means the car stopped running .. Seriously, 0 RPM would mean that cylinder is completely dead (caused 0 RPM decrease in base RPM after shutting that cylinder off)....

[elwesso]

I merged tihs thread with the one in the Q45 forum.

[maxnix]

I merged tihs thread with the one in the Q45 forum.

Thanks you. Double posting wreaks havoc on searches.

[96Qowner]

Here are the power balance readings after the BG system flush:

#1 -49rpm#2 -54rpm#3 -48rpm#4 -23rpm#5 -70rpm#6 -55rpm#7 -57rpm#8 -49rpm

CMPS-RPM 1063Temp 84*C

Not bad, huh? I'll see if it has more power tonight on the way to the lake.

[Q451990]

That's a major improvment, but still a lot of variance on injectors 4 & 5. Maybe another flush is in order? Make sure they're plugging the return line to the fuel tank so that all of the cleaner is forced through the injectors... takes longer, but cleans much better and prevents sending garbage back to the tank.

Heath

[Q45tech]

You never thought you were buying such defective dirty gasoline nor driving in a style that would dirty up injectors in such a severe manner.......did you?

It should get better if you run another can of BG44k..........some times it takes a long time to clean the 94-96 injectors vs 90-93 pintle type.

[96Qowner]

Unfortunately, because it's a highway car for me, I've run gas through it from stations all across the country. I always look for a Shell or Chevron station while I'm travelling, but locally, I'm now stuck with 91 octane most of the time, primarily Phillips 66. I talked to the owner of the station and he assurred me that there isn't any ethanol in the 91. At the lake, I have a BP station that offers non-oxygenated 92, so I fill there whenever I can.

BG44K isn't good for the oil, right? I shouldn't use it until I'm close to an oil change again?

I'm a little suspicous about those first power balance readings. The second set had minus signs before the rpm numbers - the first set didn't, plus it had all those stall readings. I asked him if maybe he'd done it wrong, and of course, he said no - in fact he said he did it twice.

Incidently, this is the tech I gave the $40 restaurant gift certificate to as a tip. While he charged me 1 1/2 hours for the t-stat swap It was only $92 for the first test and I got the second one for free, and because they forgot to change my oil the first time, they did that for nothing, too, as compensation - they offered - I didn't ask. He's also VERY attentive to me, and for some reason, the service writer wants to please me too. Just a word to those who disagree with tipping.

[elwesso]

the minus signs could be they used a different consult.. Maybe consult I vs consultII??

[96Qowner]

Nope, they were both Consult II, with a tape readout. Now that I think of it, a stall is sorta hard to mistake, heheh, so it was what it was. Dunno.

[maxnix]

the minus signs could be they used a different consult.. Maybe consult I vs consultII??

Consult I is OBD I only. 1996 G50 is OBD II, so requires Consult II or OBD II reader.
Modified by maxnix at 12:59 PM 6/16/2006

[Q45tech]

The Consult I works fine with 96Q ........dual systems and dual connectors same with 97Q.

[maxnix]

The Consult I works fine with 96Q ........dual systems and dual connectors same with 97Q.

Really? Does Consult I read and record all the parameters? Thought they were completely different (8 bit CPU vs. 16 bit CPU).