TB42E idle/stall/rough - ignition? fuel?

[OllyTheFrog]

Hi all,

I have a 97 TB42 LWB auto with EFI which has a real problem, perhaps linked to humidity... let me explain:

Just over a year ago it broke down on the motorway in pouring rain. It just stopped with the check engine light on. I tried restarting and it caught but was REALLY rough, idled but wouldn't drive. Cutting a long story short, the Nissan dealer diagnosed a distributor problem and replaced it (900€!!). When I picked the car up, it was still running rough, but that was "cured" by disconnecting the speedo sensor (!). Since then, it's been running ok as long as the speedo sensor is unplugged... plug it back in and it plays up again.

However, yesterday it died on me again (even though the sensor was unplugged) in the rain... same symptoms: splutter, loss of power and eventually stall with check engine light. Got it towed home and am tearing my hair out!

Have checked the on-board diagnostics... comes back code 55 which is "no fault". Have checked fuel for water, nothing. No sign of moisture in the dizzy cap or in the inlet manifold. Oil, water, fuel levels all fine. No obvious problems on hoses, etc.

It starts, but idle is choppy with the rev needle wavering about and after a short time (up to 2-3 mins) it'll stall. If I hold higher revs (say 2500) then it is the same. It's an auto box, so when I put it in drive it goes, but when I accelerate it stumbles and eventually grinds to a halt.

I have the Haynes manual and have tried following the check procedures in there. The only one which did not check out was the power transistor which had continuity between some of the terminals which - according to the manual - it shouldn't.

Any thoughts please... I'm loosing the will to live! :headwall:

Thanks in advance!

[GQ Bear]

Mate, i've got a similar gremlin living in my engine bay.:angryfir: :angryfir:

I'm a new member here and this is my first post. I did a google search for TB42e problems and OllyTheFrog's post came up so i joined this forum. G'day all. Here's my story, hope someone can help and i hope i can help some of you in the future.

Here we go,

It first happened in Queen's Birthday w/e in June up at Gembrook. Car was running fine then hit puddle/bump and it backfired, lost power and stalled. Blew airbox apart so tie-wired that back together and it was idling rough as guts. Tacho needle was all over the shop and the eng mgt light was displayed.

We played around with a few things and, suspecting water, pulled air ducting and airflow meter off. Putting these back on seemed to reset fault and away we went. Happened a couple more times that w/e and same remedy fixed it.

Went to Woods point on snow discovery trip and it ran beautifully all day untill we were ready to head home and it played up big time on a very difficult 4wd track. Not the place to break down. Impossible to tow a vehicle out of this place. Anyway the airflow meter trick seemed to work and as long as ran on gas it was ok for about 5ks or so and die. 5ks and die. All the way home (about 100ks). Tedius stuff.

Anyway i got a new airbox and had no problems untill the next time i went 4wheelin'. Friday night plugging through deep water and mud was not a problem in Narbethong. First decent hill at Big River the next day and the problem came back to haunt me again. This time it wouldn't reset. Parked car at camp and it purred like a kitten the next morning - untill we hit first 4wd track when it once again played up. Still suspecting water i siliconed anything and everything that wasn't already silicon or rubber. The air induction system is now so watertight it could be used as a low suction, mobile vacuum cleanerPulled distributer apart and cap and rotor were in terrible condition, Hmmmmmmmmmmmm.

Got a new cap and rotor and car drove like a new machine. OK, let's go wheelin' again!! Headed out to Gembrook a couple of weeks ago for a day trip as it's nice and close. First 4wd track, you wouldn't believe it! Bloomin' thing loses power and stalls just after hitting first decent bump in Low 2nd. Starts running rough again. Stuck on an incline i pushed it up this hill in low 1st with eng mgt light still on and running like a bag of ****e.

We pulled dissy apart again and cleaned it up a bit more, etc, etc. Eng mgt light stayed on all day and car ran like a bag of ****e all day. Pushed it out up and down hills, over rocks, through creeks, the works. Limped it home that night and she's still sick (even in 2wd this time).

I took vehicle to local Nissan dealership and they did a diagnostic test. Came back showing no faults. Their mechanic reckons it sounds like cylinder problem or split exhaust valve in no.5 cylinder. I've recently had the head surfaced, new h/d valves and springs put in and gaskets replaced. Originally being an intermittent fault doesn't ring true with cylinder problem. When it had a blown head gasket eng mgt light never illuminated. This problem must be electrical. But what??:headwall:

My mate told me his mate's VL commodore suffered a very similar problem which turned out to be the Crank Angle Sensor located in the distributor. I've sourced one locally and will be fitting it on thursday. I'll also have a look at Power Transistor, if CAS doesn't solve it then PT will be the next target on the hit-list.

Any luck with yours OllyTheFrog? I'll keep you posted on how it all goes on Thursday. Anyone else had similar probs? Any solutions/suggestions.

[pedrok]

I had a crank angle sensor die as well, in an auto Symptons were
Everything was ok
stalled
would start an idle
put in gear or accerate and it died

If it is the problem the good news is they are realativly cheap to replace, with the tow out of the forest all up it was less then $200

[OllyTheFrog]

Hi guys, thanks for the input ... even if it was only to commiserate ;)

The previous time it broke down it was taken to a Nissan dealer who claimed that the OBD was giving a code for a "sensor in the distributor" and another for the speed sensor. I don't know how many sensors there are in the dissy, but crank angle sounds feasible. They told me that the sensor was not available separately and I had to order a new dissy assembly. I'm in France and the 4.2 is NOT a common engine here, so even the dealers don't know it very well. There were no parts in France or at the European distribution centre in Holland, so the distributor had to be ordered from Japan. It took 5 weeks and cost over 900 euros (1500 $AU!).

The thing was, that when I picked the car up it was still very lumpy (they claimed it was working when they tested it the previous day). The lumpiness was only "cured" by disconnecting the speed sensor (which they'd just replaced, remember!).

I've been driving it with no speedo for a year now (I rigged an Voltmeter on the speed sensor so get a reading in Volts, and have a conversion table taped to the dash!).

I was never satisfied with the explanation of the fault and have noticed an increase in fuel consumption since the speedo has been disconnected ... probably something to do with there not being the feed back to the EMU so the mixture is not being adjusted for the road speed.

This new breakdown seems to have the same symptoms as before, but unlike GQ Bear, there's no quick fix to get it going again, even if only temporarily. It'll start no problem from cold, but idle's roughly with the rev counter jumping all over. It will rev to about 3000 - still wobbling - but won't pull max revs. Put it in gear and it'll go, slowly, for a few hundred yards then die. If you repeat this too often it won't start again unless you leave it for 20 minutes or so.

I spoke to a guy at Haynes in the UK who suggested that if the power transistor was defective then it could lead to the coil overheating which *could* possibly explain the symptoms - although he would have expected it to cut out for 10 seconds or so.

Is there any way of testing the PT / coil in situ with the engine running diplaying the symptoms? I'm thinking that if the problem is there, then some sort of tester inserted between the coil and the dissy ought to show fluctuating results? What equipment would I need to do this?

[Wheels]

I had the same problem on my carbie model. I found the balast resistor faulty after it heated up. If I by passed the balast resistor on the coil the car would idle again and pull like a new car.
I would measure less than 9 volts on the coil terminal with the balast resistor heated up.

[OllyTheFrog]

Hello Wheels and thanks for the tip.

Unfortunately, I'm going to sound like a real dork now... I was looking for the ballast resistor and couldn't find it. The picture in my Haynes manual just doesn't seem to tally with the vehicle.

Can anyone confirm for me that these pictures do in fact show the coil / power transistor?
http://www.donfi.com/_temp/20071212-150925.JPG
http://www.donfi.com/_temp/20071212-150853.JPG

Also, I mentioned that I suspected humidity as a culprit. Well the rain stopped last night and we've had a gloriously sunny day today. Guess what ... no more problem! The car starts, idles and runs fine! :rolleyes:

Anyone got any tips on how to proceed to try to find which component might be at fault?

Thanx all!

[Tracteur Tom]

Olly, does it not seem to be humidity related ? I dont know this engine so its only a guess (and I know what you mean about the rain in France !!) but I'd be looking for a loose connector or a dicky earth connection somewhere. In your pics there are some rusty looking earth connections ??? Clean them up and apply some silicon grease. Also silicon grease all connectors - take apart, inspect for anything iffy and reassemble using silicon grease sparingly. If any of the connectors have had water in you may see the telltale white crud. After having paid 900 euro for a new dissy, I'd be knocking on the door of Mr Nissan telling him that the problem was not fixed - Mr Angry style !

[OllyTheFrog]

Hi Phil, yes I agree that it has got to be humidity based. I was thinking more along the lines of damp in an electrical component, but the earth idea is not a bad one. I will go over all the earths I can find, take 'em off, clean 'em up and cover them with vaseline.

I'll also go over every connector I can find too.

You're absolutely right about the Mr Angry suggestion. The only problem is that where I broke down and subsequently was towed to is 6 hours drive from home, so I'm not likely to take it back to them even if they accepted it. The only other option is to get a local Nissan dealer to take on the repair and get them to sort it out with the original repair people. This being France, I think that the likelihood of actually getting that to happen is pretty damn slim!

The other thing that's putting me off taking it even to my local garage who I'm personal friends with is that the nature of the fault is intermittent and damp-related. Now that it's working again, how to tell whether work that is done has permanently fixed it until the next time it breaks down??? It'd be like writing them a blank cheque! No, I think I prefer to potter myself for now... you never know, if earthing is the problem, it may also cure the speedo problem and allow me to connect it again!

[DreamPatrol]

under bonnet electrical connectors.

I have found that the connectors for the CTS (Coolant temp sensor), TPS (Throttle position sensor), PTU (Power transistor unit), AFM (Air flow meter) CAS (Crank angle sensor) and virtually all other conectors are prone to internal corrosion.

I have a 1990 Nissan 300ZX which uses virtually the same connectors and electrical component set up as my EFI Patrol. The 300 ZX is prone to connector corrosion and I found by checking each electrical connector most of them had a build up of green crud that can be scraped off with a small screwdriver and contact cleaner spray.

By doing this it often helps cure rough idleing and poor fuel consumption.

Check out some of the technical stuff on this site www.aus300zx.com (http://www.aus300zx.com) and search under the electrical section for "rough idleing" and you will see many similarities that could relate to our vehicles especially the CTS, TPS, PTU, AFM and CAS info. A lot of the problems found on the 300zx (and cured) are similar to what are found on the EFI patrol and probably all vehicles with EFI and ECU control.

The electrical equipment and sensor connectors supply all the information in regard to electrical voltage and resistance back to the ECU to allow it to adjust the fuel maps and ignition to make the engine function correctly, if these signals are affected by poor connections and the readings change out of spec, the ECU tries to compensate and changes the timing and fuel maps accordingly so the engine will still run but not how it is meant to.

So a little time cleaning and re lubricating the connectors with electrical grease can make a big differences to performance.

Faulty electrical components and sensors are often blamed as failing and replaced (quite possible and correctly), when in fact just the act of disconnecting the connector and re connecting after replacing the "faulty component" could possibly have been the problem in the first place, but because the replaced component now works it must have been that which was faulty so you pay your money for a new component and feel good that something was found faulty.

Hope this helps a little.

[Tracteur Tom]

This being France, I think that the likelihood of actually getting that to happen is pretty damn slim!



oh so true !!

The post by DreamPatrol is also spot on.

[GQ Bear]

OK, i said i'd report back. Replaced crank angle sensor. Dissy was full of muck and gunk and water. Thoroughly cleaned this aswell.

Runs beautifully on gas, bit of a flat spot on petrol. Maybe a tuning issue??

CAS was sitting in water. Obviously wasn't a problem untill successive bumps caused water to splash onto sensor part and send it haywire. That's why it only did it 4wheelin, i hope anyway. Will take it out for a run in a couple of weeks to test theory.

[Lockee]

Hey Bear, is it fixed now? My new Ti has been giving me grief over the weekend. Would start and run then cut out. Crank Angle Sensor was the culprit when I got the Snap on scan tool to check it.

At least I have a new coil and module(power Transitor) now, and working spares.

[fordnes]

For the carbie models we have found the emission control unit thing on the side fails. We got sick of stuffing around with it so we bought a 350holley with a adapter to fit the SWB.

It is alot better and would highly recommend doing it if you are having problems with your carbie.

We have found you get better fuel economy compared to the orginal carbie and a hole lot better for towing.

They retail for around $500 for the kit.

My 2cents for anyone with carbie issues.

[GQ-sby]

Wow. that's a good news for us with faulty carbie.
So the holley with the kit will bolt on directly to the intake manifold right?

Can you please give info of what company sell the kit?

And one more thing, is it 2 barrel or 4 barrel carb that come with the kit?

[fordnes]

Wow. that's a good news for us with faulty carbie.
So the holley with the kit will bolt on directly to the intake manifold right?

Can you please give info of what company sell the kit?

And one more thing, is it 2 barrel or 4 barrel carb that come with the kit?

GQ-sby - Yeh it is so much better. The company supplies everything you need including adapter plate, new turned 2 barrel holley for the patrol, throttle cable, air filter and everything you need to bolt it straight on the existing intake.

I ask my bro were he got it from. He got it off ebay somewhere ill get the link and post it.

The only thing that we havent got around to is the standard airbox on the patrol doesnt fit the top of the holley. You have to modify it to suit.

Ill get the link for ya.

[fordnes]

ok. found it.

Heres the link. tou tell you everything you need to know.

http://cgi.ebay.com.au/Patrol-GQ-4X4-holley-carb-conversion-TB42-RB30-engine_W0QQitemZ330294643725QQcmdZViewItemQQptZAU_ Car_Parts_Accessories?hash=item330294643725&_trksid=p3286.c0.m14&_trkparms=66%3A2%7C65%3A1%7C39%3A1%7C240%3A1318

[pigsy]

350 Holly looks good but what sort of milege are you geting
how many litres per 100klm .

thanks for your reply in advance.

[fordnes]

i am pretty sure he gets around the 450km to a tank of 95ltrs. That is towing a 18ft glass boat to the ramp a few times and out the dam a couple.

He drives hard too.

So if you drive like a girl you might get better economy. Talk to old mate on that ebay site and he will tell you all about it, he is a top bloke.