We haven't seen or worked on this machine for a few years, but the customer called the other day, no starting. One of my techs went out, I don't remember the code, but it could be the cam or crank sensor and he replaced both. He mentioned the cam sensor plug was cracked up on the outside. After this, he finally got it started and found he had a bad miss on one cylinder he thought. I ran him a compressor pressure tester to site, and checked again and found #3 and 4 cylinders not firing. We checked compression. Had well over 210 each, checked for an intake leak. All seemed fine. We installed new spark plugs in 3 and 4 ( yes- the special ones) and no help. We then swapped 3/4 coils with 1/2 coils and now 3/4 will run the engine, but 1/2 are no longer contributing. So.... We ordered two new coils and I went myself this morning to install. I tried to start the machine when I arrived, but it would crank and die. Installed the two coil packs, same result. I checked the 5 amp fuse at the injector and found that it was fine, but I would get a blinking voltage there, then when it started, the blinking would stop and the engine would die. I pulled the busted up plug loose from the cam sensor and I then get no "blinks" at the fuse, so this seems to indicate the problem?? Any ideas out there?
Nissan MCUL02A33LV
SN 9Q0119
Showing items 16 - 30 of 46 results.
Depending on model of truck , some had final chance screen behind the top mounted lpg pressure sensor and some had them located behind the fuel supply nipple on the injector holder its self. With KOEO do you hear lpg spewing? If so, it is flooding. See which oriface the spewing is coming from on the injector holder. if it is the larger hole 1200 o'clock position then you have a sticking injector. if it is the small hole at 3 o'clock position , you have a sticking relief valve in the injector holder its self. This requires new injector holder. but first be sure you check the small 5 amp fuse on the main lpg injector.
Can we back up to the comment about a last chance filter screen in the lp line? Are you sayin to pull the lp line off the injector housing inlet and there is a screen inside the inlet nipple? I have the same k25 that has a crank no start issue. I have spark at the plugs but I checked the throttle body with the air intake tubing removed and didn't think I was getting enough lp. I have plenty of lp pressure at the line coming out of the vaporizer to the injector
I always give the customer the choice on whether to use aftermarket or OEM - especially with electronic parts. I'm tired of eating labor because the part is incorrect or faulty from the get go. If they give the go ahead on aftermarket & it doesn't work then they get billed all the labor for the install of the bad part along with the new OEM part. Doesn't take too many of these situations to happen when OEM is all the customer requests.
Same here. Haven't had any issues with them for a while but won't use any more of these.
Got it. Thanks for posting. I'm starting to wonder about the TVH sensors now....
This truck came in for a no start problem. No spark. (It's a Tusk 350CG-17 with the K21) After replacing the cam and crank sensors still no start but a blown fuse was found in a harness above the valve cover. Fuel pressure was also high. After changing the regulator it would start when it felt like it. We put the original cam and crank sensors back in and it took right off. After troubleshooting sure enough it was a bad TVH cam sensor. Thanks for the help!
a bad crank sensor will make it have NO spark at all, (the ECM requires 2 rotations to be "sensed" through the crank sensor, before any spark at all happens). the cam sensor (if bad or disconnected) will barely allow any spark, just enough to make you release the key from the crank position. MOST Nissan k21- k25 series motors give pretty good error condition codes, and should set a code for either of these conditions that is readable with the software, or in the dash.
Just in the last month, I have had a series of brand new bad cam sensors from TVH, (for K21-K25 Nissan motors) and resorted to having the local Nissan Dealer get one OEM that worked as it should.
Thank you for the reply. I will let you know what I find.
Gear head, I had the local dealership take the baton on this repair after discussing it with my customer. Their tech said he could have Nissan work with him after installing the updated injector if it still didn't run. Well, he installed it and it still didn't run. Then the story I got was he ordered/ replaced the wiring pigtail to cam sensor. No help. Then Factory had him replace the crank and cam sensor with OEM parts, and this made it start and run. We use TVH parts, and had already swapped them to test once- so I'm not sure I buy the story. My customer (yes still 😊)approved having me reinstall the "defective" parts to see the result, but only one of the two sensors could ever be found......
Keep us posted.
What did you figure out on this? I have one doing the same thing.
Yes the secondary\assist can leak, it happen to me a few times , when it happen it have a build-up of oil and the injector stay open. When the oil heat up , it start to act normmal. Oil residue can be found in injector holder and vaporizer. Try to clean it all.
Alanmitsu, those are good points. The dealer tech came back today and repaired air flow sensor wiring (it wasn't broken, but the insulation was pretty ragged) and then installed a new air flow sensor, but no help. As you mentioned, he also said it wouldn't throw a code. I had ordered and we replaced the LP filter at the lock off, still no help. He thinks we should replace the injector- so I'm gonna check with the customer tomorrow.
Tell me more about the assist injector- I know this only fires under high load/ high RPM. Can it leak/ bypass?
If all the fuel filters clean solenoid and manifold fuel pressure ok make sure assit injector free injector most likly faulty they have just been superseded to a new no now teflon coated check wiring to airflow sensor they often break worth trying a new airflow meter as they dont throw up a code can all be checked but you would need the lead and gse programe
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