decent consult software

[Drake57]

Can anyone say what is decent consult software? My 92Q has a hard solid miss on one cylinder, doesn't power balance test allow turning cylinders on and off individually? I think that's what I'd like to do. I'm ready to buy one of the rs232 consult cables, would like to know what is a decent consult software. Thanks, Drake.

[Infinitiguy19]

A while ago I was putting together Q45 Diagnostic. But then I got busy.... The point of that software was to make it better than anything else out there and free to anyone of any tech level.

I will consider any help in any useful way.

[Drake57]

Is it ready? Will it configure with an RS323 port? I'd be glad to try it, I need to get my miss figured out. If I understand, some of the consult software allows a user to individually turn a cylinder on and off, I'd like to try that to determine which cylinder is not firing. Will your software do that?

Thanks.

[Drake57]

More to the point, I've listened to all 8 injectors w stethoscope with engine idling, all sound the same, so I think the injectors are all firing. Has any one used an induction timing light to see if a coil is firing?

May the coils be tested off of the car?

Thanks, Drake.

[goody90q45]

.........I've listened to all 8 injectors w stethoscope with engine idling, all sound the same, so I think the injectors are all firing........

Coils don't normally go bad on the G50. Have you ohm tested the injectors? It will take about 5 minutes and may pinpoint the problem. The cluster of connectors shown in the pic is located on the passenger side of the plenum.

[kevindanielk]

Nissan DataScan 1.52 has an active test option. I have used it to shut down each of my cylinders, one at a time. I posted a link to that program, and a few other consult software, on the thread below; The downloaded file is PW protected but I included the PW in my post. They are not my downloads, just what I came across in my search for consult stuff.

thread-for-nissan-obd-scantech-testers-t248654-30.html

[Drake57]

.........I've listened to all 8 injectors w stethoscope with engine idling, all sound the same, so I think the injectors are all firing........

Coils don't normally go bad on the G50. Have you ohm tested the injectors? It will take about 5 minutes and may pinpoint the problem. The cluster of connectors shown in the pic is located on the passenger side of the plenum.

Woops, not so good for me, cylinders 1,3,5,7 all tested 12 ohms. Sadly, of the even numbered cylinders, one tested 12 ohms, another was 24 ohms, cylinder 6 tested open. I'm going to retest them again this eve, then maybe remove the plenum and test each injector. If the injector(s) are fouled, I want to get Deatsch new design injectors and rail service, but I need to be sure before going that kind of cash.

PS is cylinder 1 front passenger side? Are all even on driver side?

[goody90q45]

It looks like you've found the engine's miss. Fuel injector (FI) #1 is the driver side front closest to the radiator, #2 is passenger side front, #8 is passenger rear closest to the firewall. Odd numbered FI on the driver side, even numbered FI on the passenger side. To verify the readings you got you can ohm test #1, #2 and #8 directly on the injector without removing the intake. Remove the center plastic shroud and you'll see #1 and #2. Look between the intake runners in the rear and #8 is right there. Put the probes of your voltmeter directly on each of the pins of the FI.

[Drake57]

LN I removed plenum, and #6 is open, #8 measures 12 ohms, #4 measures 32 ohms and #2 measures 16 ohms. 1,3,5,7 all measure 12 ohms. It seems as the even injectors are headed south.

On the bright side, I do have a lower mileage engine in my parts car, that doesn't leak oil like this one does, so it may be time to swap. Happy friday everyone!

[Drake57]

OK, long story shortened, I replaced injectors w a set of 8 upgrades from Deatschwerks, LN I started it. Injector 2 is silent to stethoscope, others tap a nice happy tune.

All injectors tested good at 11 ohms at the 8 pin connector atop the right hand valve cover, not surprising, all are new.

Tickling injector 2 w 12 volts caused audible clicking - car was not running at this point, obviously.

Tonight I will ohm connector at ECU.

Aren't ECU injector driver failures uncommon? I never seem to hear of it.

More later...

[Q451990]

ECU failure is very rare, but if you have a spare - I'd certainly swap it in and see if that's the problem. It kind of sounds like it if there's no pulse for that injector. I think Dennis mentioned that the transistors(?) in the ECU that feed the injectors can burn out if certain conditions occur.

Heath

[Drake57]

Well, after another resistance check, reconnected injector harness, fired it up, and all 8 are tapping same happy tune. Before, I'd applied dielectric grease to connectors, so who knows.

Idle air controller connector at throttle body was not connected, this caused 1800 rpm "idle", connecting brought idle down to 600.

Car now starts right up, idles nicely, bogs when throttle is opened, have to open and close and open throttle a few times to get it to pick up and rev. Fuel level is low, fuel is at least 18 months old, I'm going to try fresh fuel next.

So, good news here so far, more later.

[Drake57]

I've added gas line antifreeze to fuel, it seems to make bogging better, but something still is wrong. At times the car just dies, right after shifting from neutral to drive, for instance, but starts back up immediately. Other times, it will bog and die when starting from a dead stop, under light throttle.

Where is best place to measure vacuum, and can anyone say what a proper reading is at idle?

Thank you.

[Drake57]

Nissan data scan was revealing - all 8 cylinders are hitting, idle slowed noticeably when disabling each, then returned to normal after enabling, one cylinder at a time. Self diagnostics showed only knock detect circuit failure.

The main problem is that the engine is very slow to pick up when opening throttle - 2 to 3 second lag, and backfires through intake occasionally, tends to stall on acceleration from idle.

Setting AAC from 0 to 15 had no effect on idle speed, 20 and higher does show effect. Idle is a little rough, varies from 800-900 after warm, trans in park.

Setting fuel base to 125 improved lag in pickup. EGR solenoid on/off had no effect.

At this point I suspect an intake manifold leak, I've had this cold shouldered running since replacing the injectors. Usually if there is a gross leak, it's easy to hear, nothing is obvious here, though engine noise may mask.

I may repeat the same settings on parts car, as a point of reference. Thanks in advance for any thoughts.

[Drake57]

Hallelujah, I found it!

Turns out, during replacement rail and injectors, I left the large (30 mm wrench) compression nut on the EGR (connects thin wall tubing that runs down to exhaust) loose. Inexplicable as it sounds, that causes a lean condition, lag and backfire through intake on acceleration, basically runs like hammered sh*t. Snugging up the nut drastically improved running, it passed smog, I'm going to register for the first time in six years come Monday. I was just about to remove plenum, trying to figure it out, when I brushed the EGR, noticed looseness.

Strange story, I know, but happy ending for now.

[94Q45Beast]

IF its been sitting for 6 years, TBH, I would keep a jack, jacks stands, and a tool set in the trunk with extra fluids (engine oil, ATF, coolant) with a pack or 2 of jb weld, and closely monitor everything and thoroughly inspect everything. it was fun but labor intensive for me resurrecting my Q after 6 years of just sitting there under a pine tree uncovered. and it was parked there in near mint condition. so....just watch out and expect the unexpected.

[Drake57]

Thanks. Mine's been sitting inside, I've done a lot of work on it in last three months. It's all looking pretty good. That ragged throttle pick up was hard to find.

[94Q45Beast]

sooo....about that decent consult software.....

[Drake57]

I like Nissan Data Scan I, it seems worth the price - It did not pinpoint the source of my grief, but did reinforce my suspicions, and the individual cylinder on/off capability and other features in advance test window are nice. The full instrument panel gives a helpful comparison of a good running car vs one that's not quite right. So I'm well satisfied with it.

[94Q45Beast]

was that the free version? will it record MAF readings?

[Drake57]

Free version will show RPM, and very little else. Registered versions does allow simultaneous logging (recording) of nearly all sensor values, including MAF. I did not personally test or verify logging, but the menus are there to set it up. Registered version seems reasonable, at about $40 US.

[maxnix]

Has anyone done an article on this? Might be helpful.

[mattd1979]

obdscantech is free and does all that was mentioned on the above post and also does a full power balance test or you can manually turn each one off one at a time. I currently use version 1.51. I also have version 1.53 but have never been able to get it to connect.

[Drake57]

So maybe I wasted my $40.00, but NDS seems like a good package, I'm glad to have it.

[92Q45_Greenish]

Searching for help with diagnostic Consult 14 pin adaptor and Datascan 1 type software. Wondering what is a recommended setup for 2017 to troubleshoot a 1992 Q45? Wondering if a 14 pin to 16 pin OBD2 adaptor is a good option and then use a more versatile OBD2 software to troubleshoot the 92 Q + be able to use it on newer OBD2 cars or is it best to stick with a dedicated OBD1 setup to diagnose this car? I have a steady misfire and no power in gear. In park it will rev up good but has a little lag / stumble. Once in gear though, 1500 rpm is the max - maybe a limp mode issue going on. Replaced injectors about 1200 miles ago after which the car ran well but has now deteriorated to a similar condition as when the injectors were replaced before (with rebuilt ones).

[Drake57]

I think the only scan tools that will work w 92Q are consult adaptor and NDS, or obdscantech. NDS allows an override mode, where one may crank up the fuel mixture, to see if car is running lean, which is what I would suspect in your case. How about fuel pressure? Don't forget fuel pump modulator, that's a known failure mode.

[92Q45_Greenish]

Thank you for the tips and confirmation about the diagnostic software options. Last weekend I pursued the idea that I had clogged exhaust so I dug in and found the two upper cat's had come apart and had melted chunks of catalyst. I cleaned out all 4 cats thinking I had found the low power problem - but it didn't help. I had intended to check fuel pressure and plan to do that next also - Didn't know about the Fuel Pump Modulator - I'll look on here for troubleshooting steps for that issue. I've also checked the MAF with an ohm meter and it measures OK.
Thanks again!

[mattd1979]

My car has been down for a little more than two years now and I have slowly been repairing/replacing parts, mainly the engine. I lost compression on cylinder 7 and had a steady misfire like you. I came to the conclusion that I had a broken compression ring or ring land after putting oil down the cylinder and doing a compression test comparison. I recently dropped the exhaust in preparation for pulling the engine to replace with another and found that the pre-cat on the driver side. Same side as cylinder 7 had also come apart. I determined that cylinder 7 must have ingested part a piece of the pre-cat which in turn damaged the rings on the piston. Cylinder 7 also has the shorted exhaust runner on the manifold.

Have you done a compression test also?

[92Q45_Greenish]

No I haven't checked compression yet but will try that also. I'd like to check what I can before investing in the NDS software but I think I will probably get that anyway. Previously I had the spark plugs changed and the coil packs tested fine and ultimately a new set of rebuilt injectors got it up and running good again - for about a year or so. Its not a car I drive much and I know that sitting around doesn't help. I also try to put 93 octane non-ethanol gas in it but its getting hard to find and I don't think that ethanol gas accounts for this issue would it? What have you heard about pump-gas options? Heck - I even bought a 2 gallons of "race gas" (110 octane I think?) and mixed it in about a 1/4 tank and it didn't seem to make a difference.

[mattd1979]

I would check compression on all cylinders to see if you come across any particular one that has a significant compression drop. You can easily rule out the injectors by checking resistance. They should be between 14 to 18 ohms each.