Nissan Forum banner
1 - 8 of 8 Posts

·
NF Mod/Nissan Master Tech
2006 Pathfinder LE, 2003 Frontier SVE
Joined
·
10,669 Posts
Since it appears that the engine is running rich, the first thing I would do is check to make sure the vacuum hose is attached to the fuel pressure regulator at the back of the engine and then test the fuel pressure with a fuel pressure gauge to make sure it is within specs and not excessive. Also, make sure the coolant gauge needle is about in the middle when the vehicle is at normal operating temperature. If it is sitting at the lower end of the gauge, near the "cold" range, you may have a thermostat stuck open that needs to be replaced. If all is good at this point, definately look at the ECT sensor and make sure it is reading correctly and the circuits are good.
 

·
NF Mod/Nissan Master Tech
2006 Pathfinder LE, 2003 Frontier SVE
Joined
·
10,669 Posts
If it's a single wire switch, it's likely the temperature sender for the coolant gauge. A fuel pressure gauge might be available through a loaner program from your local parts store. Simply tees in between the top of the fuel filter and the fuel filter hose. Turn the key "on," and you'll see the pressure raise on the gauge. Start the engine and it should be around 34-36 psi. Disconnect the vacuum hose from the fuel pressure regulator and plug it off, the pressure should raise up to somewhere around 45 psi +/-. If the "regulated" pressure is higher than 36 psi, you may have a lack of vacuum to the regulator, bad regulator or a restricted return fuel line. Excessive fuel pressure will push more fuel through the injector than should, causing the engine to run rich.
If you are doing a water pump, check out the "Gates Timing Componant Kit w/ Water pump" at Rockauto.com. It gives you the timing belt, water pump and tensioner along with instructions and a mileage sticker. Good quality parts at a very reasonable price (and usually a lot cheaper than what you can get the same parts for at the local auto parts store or dealer). I use them a lot on the VG engines. I would recommend you get the front cam and crank seals, as well as the thermostat, from Nissan. If you are replacing drive belts, I would get them from Nissan, as well.
 

·
NF Mod/Nissan Master Tech
2006 Pathfinder LE, 2003 Frontier SVE
Joined
·
10,669 Posts
My experience with drive belts on Asian makes is that some of the belts from Gates and Dayco are just a little bit longer or shorter than the original belts and tend to put the accessory drives close to the end of their adjustment brackets or go on a little tight. Also, Gates and Dayco make several types of each size, so if you do go with either of them, make sure you get their "premium" belts made with EDPM. A lot of aftermarket belts seem to have issues with squeeking not long after they've been installed. The original belts on Nissans are usually made by "Bando" or "Mitsuboshi" (not "Mitsubishi"). Bando brand belts can be had on the aftermarket from part stores like NAPA and Federated Auto Parts, but often have to be special ordered. So, if you go with aftermarket, I would recommend you get the Bando. There usually isn't much difference in the price of genuine Nissan belts and premium aftermarket belts, so it just makes sense to stick with genuine Nissan. As far as the seals, the Nissan cam seals have external grooves that make them install a lot easier then some of the aftermarket seals. Also, they sell the crank seal individually. A lot of times when you try to get a crank seal in an auto parts store, you have to buy an oil pump reseal kit to get the crank seal, which makes it more expensive. Genuine Nissan seals are often cheaper than aftermarket seals, as well. So, it just makes sense. You didn't mention it, but aftermarket thermostats, while considerably cheaper, seem to run a little colder than the original Nissan part and I've seen some be faulty right out of the box. The genuine Nissan thermostat usually puts the needle of the coolant gauge dead center, or just a hair below dead center. I've had some aftermarket thermostats put the coolant gauge needle about 1/3 of the way from the cold mark. Nissan, like most Asian makes, can be a little tricky when it comes to replacement parts. On some parts, aftermarket if fine, if you know what works and what doesn't. On others, the only way to go is genuine Nissan, or at least the OEM supplier of those parts to Nissan (companies like NGK, Hitachi, and Akebono).
 

·
NF Mod/Nissan Master Tech
2006 Pathfinder LE, 2003 Frontier SVE
Joined
·
10,669 Posts
I have the same 94 V6 SE 4x4 truck that Crystal has, and a very similar problem that just developed this past week: Severe lugging/lurching in lower gears. It is apparent in 3rd and 4th gears as well, but not as noticeable as there is proportionately less torque transfer. The problem seems to happen only after the engine is warm - 5km or so from a cold start (that's about 3 miles - sorry, I'm Canadian). I notice it when the truck is idling too - it runs fine for 20 seconds or so, then almost stalls and revs back to normal idling speed.

Fuel delivery checked out fine. This feels electrical to me. I can't find any hints for how to diagnose the ignition coil in the service manual. Suggestions would be much appreciated - I am the second owner of this truck (we are both Engineers and good friends, and I want to keep it in the family so to speak). It has only 160,000 miles (not km; it was imported from California and modified for Canada).and has been a real workhorse.

Crystal, if you are still there, I am wondering if you were ever able to resolve this problem? On a side note, I too smell fuel when starting the vehicle on cold winter mornings. I know what causes that - the seals on the fuel injectors stiffen with age and shrink with temperature, so a bit of fuel vapour leaks out. Once the engine is warm, the seals expand and do their job properly again. I heard this diagnosis first from Click and Clack on NPR's CarTalk about ten years ago, and that was it for me. They said this is not a serious or safety issue, and you can safely ignore it if you choose.

Thanks - Trevor
Crystal's last activity on this forum was back in 2014, so I wouldn't expect to hear back. A lot of stalling (especially when hot), no start and/or hesitation issues on VG engines are caused by bad distributors. Often it's the optical sensor, but sometimes the shaft bearing will fail and/or shaft oil seal. That could also cause unburned fuel at start-up, which would explain your gas smell. Ignition coil component test is in the engine control section of the 1994 factory service manual for your vehicle, on page EF & EC-134. If you do determine it's the distributor, I highly recommend getting a genuine Nissan reman rather than an aftermarket unit.
 

·
NF Mod/Nissan Master Tech
2006 Pathfinder LE, 2003 Frontier SVE
Joined
·
10,669 Posts
Thanks so much for your prompt response, smj
!
The truck is at my Nissan dealership right now, but they lost their service manual and OBD tools for this model year/engine, hence why I am researching and soliciting opinions. Their first thought was fuel delivery, but it tested fine (at my cost). My first thought was distributor/ignition coil intermittent - so it is good to receive your second opinion. I will run the diagnostics and see what sorts of error codes appear. I downloaded the service manual and found the ignition coil tests you mentioned - thanks for the specifics. Here in Canada it can be hard to source old parts. Do you have any idea what I should expect to pay for a new ignition coil assembly? I will follow your recommendation for a genuine Nissan part - thanks for that. Regards -Trevor
They don't need an OBD tool for this vehicle. All the OBD tool does is allow them to remotely do what they can do at the ECM using the red and green LED lights in it and the mode selector screw. If they need a factory service manual, tell them to go online:

(replace "*" with "nico club" minus space)

And for manually checking codes:

 

·
NF Mod/Nissan Master Tech
2006 Pathfinder LE, 2003 Frontier SVE
Joined
·
10,669 Posts
Thanks again smj. The diagnostics look straight forward to me. Can you tell me where I can find the replacement part numbers in the service manual? I am wondering whether the distributor, optical sensor, shaft bearings, etc. that you mentioned are sold individually or as an assembly. I will ask the dealership about ordering Nissan re-manufactured parts, but I might end up having to source these parts myself. By the way, if you are looking for an easy place to download the entire service manual as a compressed file, try this: Nissan Hardbody D21 Truck Service Repair Manuals. Thanks - Trevor
The service manual doesn't provide part numbers. You can look up part numbers at NissanPartsDeal.com. Nissan doesn't sell shaft bearings for their distributors, but if you search the web...and possibly this site...you can find people that have replaced the bearing and provide part numbers. It looks like the Nissan reman for the Hardbody V6, # 22100-88G01RE, is no longer available, so the only option is aftermarket for distributor replacement options.
 

·
NF Mod/Nissan Master Tech
2006 Pathfinder LE, 2003 Frontier SVE
Joined
·
10,669 Posts
ECM is under the passenger seat; it's a lot easier if you remove the seat out of the way. You "may" just need to repack the wheel bearings (get new seals) rather than replace. They aren't sealed hub units like modern vehicles and do require periodic servicing. With the driveshaft center support, stick with the genuine Nissan part; if it's not something you feel comfortable with in replacing, you could remove the shaft and take it and the new part to a driveshaft shop or independent auto repair shop and have them replace the center support for you. Front calipers aren't hard to replace and you can get "loaded" calipers for $47 ea. at Rockauto.com that include the pads and mount bracket. I would also recommend new front brake hoses, with Rockauto carries at dirt cheap prices. I would go with Moog or Mevotech Supreme as far as the lower ball joints which is a bit harder to do and one needs to be careful. You could also always get a second opinion from a reputable independent repair shop.
 

·
NF Mod/Nissan Master Tech
2006 Pathfinder LE, 2003 Frontier SVE
Joined
·
10,669 Posts
The knock sensor generates a voltage when impacted, so a dead knock sensor wouldn't cause the ECM to retard the timing. Typically, they almost never cause a drivability or performance issue with the exception of the supercharged VG33ER engines. They do go bad and they are a pain to replace because they are bolted to the top of the engine block and the lower intake manifold must be removed. You may want to look into relocating the knock sensor, as many do. A knock sensor and subharness from a 95-99 Maxima is used. The one end of the subharness plugs onto the knock sensor and the other plug is cut off. The wires to the knock sensor are located within the EGI harness and cut and the new subharness w/ sensor is spliced in. The knock sensor is then bolted to the engine, often at an intake manifold bolt location. It's not a sensitive as a location as being directly on the block, but it saves a lot of work and some money in parts. There's a thread about how to do it at ClubFrontier.org and there is probably one or more YouTube vids on it available.
Some of the specs on the older Nissans can be a bit generic. 12.44 Kohms in a spec of "approx. 10 Kohms" is actually pretty close and "probably" okay.
 
1 - 8 of 8 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top