Jeep 4.0L engine sensors I suggest you keep on hand 

Hey Doug! I got a video idea for you. How to do a totally comprehensive health check on the 4.0. Everything from compression, fuel pressure, injector performance, oil pressure, leak down, engine critical vacuum systems etc. I'm sure there's stuff I missed. Would be great to just have a good baseline reference to compare to. My buddy just managed to find a non running '92 wrangler for $500 that only needed ECU "brain surgery" and fired right up. Knowing how to check the health of the motor and to check that it's running right would be nice to see what next steps are needed to make it a reliable daily.

As an XJ enthusiast I can attest to the need for spare sensors! Great video.

Great reminder. Rummaging through a junkyard is a great way to spend a Saturday morning.

A video like this for the 4.7 would be GREAT!

By the way just change all 3 throttle body sensors. WJ feels like different vehicle.

Awesome video, as a new XJ owner I'm gonna put this to use.

Hey Doug! Being from the 2.5 clan in my MJ, here's what I can tell. The 2.5 is actually really reliable and doesn't have that much sensor problems. However, its problem is popularity and rarety. Many sensors are on close-out deals even on Rockauto, especially the manual TPS sensors. Water temp and oil pressure sensors from vehicles with full deluxe cluster are worth something, ECU's are important for 2.5s, since they're rare, and has been many versions from year to year. A good functioning idle stepper motor is worth gold. And finally, air temperature sensor; IIRC, you can't get them anymore, so I converted to and AC Delco unit. It's like 1 or 2 degrees F off from the original, but works great, and I only had to change connector styles.

I love seeing videos like this. I've had a jeep for 7 years now. Been through the mountains and plenty of trails it shouldn't have been. It's been eating nitrous for over 2 years. Went to the drag strip every Thursday for almost a year straight. Put a 4.0 header on and the rest of the exhaust is 3inch stainless with a 5 inch square pipe on the end off of a late model dirt track car. Limited slip in the rear. No sway bars. All I've replaced is water pump and radiator. Never even taken the valve cover off. Yall must be doing something wrong with yours to have all these problems. Maybe you should stop caring and just drive it. The more you care the more stuff seems to break.

Regarding the oil and water temperature sensors/sending units... Make you match up to what you have in your own Jeep: gauges or "idiot" lights. The sending units are different for each case.

U are a God send, thank u for helping us keep the old school on the road longer.

Great information! Thanks for your videos.

Because of your advice, I grabbed the fan relay for my 4.7.

Great video! Thanks for posting!

Once again, you have nailed it. Extremely accurate on the TPS and the oil sending unit sensors. Drove through flooded street in the morning and by the afternoon I did not have first gear. Had to roll out of the parking lot is second gear. Made it home just fine TPS dried out overnight and in the morning. It was good as new, or as I should say good as used. One day when we get old Doug, you and I are going to sit on the porch have a couple cold ones, and complain about how these TPS sensors in these new flying cars are so much harder to replace than these WJ’s.

Sure enough, I have those kinds of spares, but they are all new parts for my now 20 year old Jeep Grand Cherokee! Though my Grand Cherokee give me grief at times, but I still love it and I know that these parts won't be around forever, I have already have felt this necessity in especially when I fully intend to do partial restorations across the board! And so when I saw this video title and thumbnail, I also too felt that I this was a must see! Since I've seen other videos dating back about 4-6 months ago on this channel, I know that everything for the Jeep enthusiast and/or professionals repair guide is all relevant no matter what and I can appreciate D&E in the Garage and the direction that the channel is going. At this point, I am an avid follower but not exactly a full time follower but i suppose that things will change in time. Some channels tend to go archaic or caveman style while turning wrenches and this would be be a turn-off for some of those viewers, but could be entertaining for some viewers! Yet for those of us that has been trained to do things the right way and to be absolutely thorough in all that we do. Example: I know of one channel that is nearly out to abuse and destroy their tools like no other and that does not suit me well at all! Tools are for to make a solid living and NOT to have to replace them every time they turn around! Those kinds of individuals that abuse and destroy tools need to be slapped up besides the noggin with a pork chop, for sure! Still, I do feel that D&E is a good channel and I just know that I can rely on some good content when I comes right down to some of those brass tacks! D&E is about one of 4 channels that I know of that can accommodate folks in a grand manner, which could be refined just a little bit going forward and I believe that every bit of their knowledge can be a big benefit to virtually any Jeep owner and it is with the building of a great community for RU-vid is where it is at. Thank-You D&E for sharing and I appreciate all that you do and with that said, here comes my subscription, coming back right back at yah's!! D&E was actually one of the first Jeep related channels that I had started getting the sometimes obscure information that I was sorely needing since I took ownership of my 2003 Jeep Grand Cherokee and so in particular, my Jeep at times has caused me some real @$$ pains from the git go! Mine is so equipped with the 4.7 Liter that has the rich and raw horsepower that some people long for but they aren't necessarily long lasting.

Where you dropped the TPS screws is home for spare CPS, oil sensor, cam sensor,cap and rotor(XJ). In the WJ it’s home for spare ECM that has been programmed. This is a super video!

Thanks bro, finding out the throttle control sensor was messing with the transmission shifting. Ran to the parts store, fixed my issue I’ve been having for months. 🎉

Spare items to add ; ignition coil, ignition switch, belt, (and for more extreme folks; drive shaft, ujoints, tierod ends, axle shafts with hub already attached,

Excellent video. Had the crank position sensor, throttle position sensor, rear main seal, water pump, power steering pump, window regulators, and axle seals immediately go bad on a "new" WJ with 160k miles. Replaced every fluid, wear component, and sensor. I keep spare parts, fluids, and equipment strapped over the rear axle behind the seat. The excess weight does have an impact going uphill, but it also improves traction in winter and reduces bodyroll. Can't always count on having cell reception and unscheduled hikes are inconvenient.

great suggestions! I guess the important thing is to make sure the old junkyard parts actually work.

Two points: (1) The TPS can start going bad, but not bad enough to set a code in the ECU, making it difficult to diagnose. One symptom of this is the torque converter occasionally coming out of lockup on the highway. Sister thought that the engine was "missing" (like a cylinder occasionally misfiring), but the RPM was actually blipping up slightly each time it happened. Torque converter coming out of lockup. Replaced TPS, problem went away. (2) A sensor I would add is the transmission Output Speed Sensor (42RE, obviously). It's very easy to replace, and in fact can be done trans-fluid-leak-free if the vehicle is on somewhat of a downhill slope (facing downhill). When the sensor goes bad, the transmission will not shift out of first gear. So now you're not technically stuck on the side of the road, but being stuck in first could have you running out of gas before you get home or to a gas station. Had that happen to my sister, also.

Just got a 96 ZJ that I'm going to fix up, thanks for the valuable info.

Nice video, clear and to the point. One correction, it's manifold ABSOLUTE pressure sensor.

My 2000 XJ is starting to act like the transmission is going. It was rebuilt about 15 months ago. They said it wouldn’t last because I have a 32” tire with 3:55 gears. I’ll try the TPS sensor first. Also losing coolant with no explanation of where it’s going. Great video

Wow d@E you did very well video make sensen thakns for your time

I can just imagine whoever buys a car from you will know immediately if you replaced any parts, all they have to look for is completely chewed up nuts and or bolts and anything that uses a torque bit, Phillips bit or anything of that nature will be completely annihilated 😂😂😂

Thanks for your video 😎👍

Great video ❤

I keep most of those in the glovebox of my 01 ram 1500 (5.2l). I've had to use the spare IAC.

Just literally 20 minutes/8 beers ago swapped the TPS from my 99 parts WJ into my 01 daily WJ and hopefully solved something I've been fighting for a week. Deep water on the road home and a coil strip and plugs later, I'm 160$ in and hopefully fixed. I'm on my 3rd WJ and it still still boggles me I can ford downstream with water over the headlights but a puddle takes me out for a week. 25 miles away from 200K.

Were you about to say Throttle Positioning System at first? Haha it happens 😆Great video though, and yes I need to gather some more spare sensors myself asap! 😎

grabbing an extra ECU would not be a bad idea, generally the only thing that goes wrong with them are the three electrolytic caps, but if they happen to fail while on a trip, you are calling a tow truck. I keep a spare for my 2.5 Wrangler in my spare parts bag.

Do you have a video on how to clean the iac housing

In 2004 WJs got a proper fan relay in the fuse block. Prior years had the TERRIBLE fan relay under the passenger headlight that required you to keep the motor on suicide watch.

Great content. I own a 99 and 04 WJ. The 04, 4.7 has a constant tapping sound. I've no idea what else to do. New push rods, rockers and timing chain tensioners replaced 😢???

Got every sensor and big brick fuse all in a tool box. No one understands why I’ve carried them all around but they were basically free. Oh and a starter in there too just in case !

Great video bud. My local yunkyard just has a bucket full of sensors that they've pulled themselves. Is there an obvious way to spot a Mopar CPS as apposed to after market garbage? Thanks for the video!

I used to be a junk yard hound but not so much anymore, although I just wish that the junkyard that I would frequent used to have a shuttle bus to get you down deep into the mix but I just don't think that they still have this service anymore..

The tool that works is the right tool for the job.

How about an update on Eric?

How do you know if a junkyard sensor is any good? Isn’t it best to buy a Mopar sensor new?

Highly recommend using Mopar sensors if available and not knock off cheap ones. It's bit me in the axx to many times. I tried going cheap but my WJ didn't like it.

Ive got one of those bags that the owners manual comes in, but im using it to hold my owners manual. Otherwise id send it your way. If i ever find one that i can scoop up, i'd gladly get it to you. I should do a junkyard run soon anyways. Im replacing a wheel hub on my Liberty on tuesday. And once i do that ill just need to ignore the huge hole in my muffler until next spring and call it good 😂

thank bunch....

What would be your suggestion? Just change oil pressure sensor on my WJ. Still no pressure on the dashboard.

I had a map sensor split in half on my WJ, like to drove me insane trying to figure out what the problem was. went to a pick and pull a few dollars later was back in business.

Thanks bud

Are there any sensors that can be pulled from the AW4 xmission? Are there any that can be added to the AW4? Pressure, temp ect... Keep us posted on the sweatshirts 👍

Don't forget about all the relays inside the interior fuse box area they control all of the starting and gas shut off relays they're in there above the fuse box very important one especially for those ignitions that have the transmitter hey Google

I have so many spare parts in my 99 Cherokee 4.0, the local parts stores call me to see if I have any extras. Now I'm stuck trying to find the cause of my #4 misfire. Something keeps frying that plug. No coolant leaks. 184k miles on it.

Where did you get that hoodie

Where did you find that hoodie

Is there a sensor that would cause a lean under power backfire ? I've replaced plugs, coil, TPS and injectors. All cylinders are at 160psi on compression with the exception of #3 which is at 101psi.

Distributor 4.0s have a cam position sensor as well, it's in the distributor, under the rotor. Parts store computers don't believe they exist, Rockauto doesn't believe they exist, but they do. I know they exist because mine has gone bad.

I have a high idle between my shifts on my manual transmission which one should I fix

9:00 Its held on with 5.5mm, I was at the junkyard today and pulled one. Bring your complete husky socket go box. Asked about those throttle body sensors 8$ each... Meh. Got a bunch more fuses today free

How you get a 4.0l hoodie?

Awesome video as always. Nice Hoody but isn't the firing order of the Jeep 4.0 153624? Your shirt has the last 2 digits reversed unless I'm unaware of something...

DANG! just found and wow, yes keep all those as a spare for a 4.0l haha.

I can't get my P0123 code to clear even with an OEM T.P.S.? I'm stuck in commy land California and get get my XJ smogged because check engine light is on? Any help would be greatly appreciated.

So we have a 2000 jeep cherokee classic 2wd, 132k miles, wiring harness looks like a rat nest and has been chopped on, I've spent days goin through the harness to re hooked all cut wires, replaced fuel pump crank sensor tried new map sensor, the and relay started buzzing on me so we purchased a new one and does the same thing, and now the fuel pump stays running when Key is turned on, we tried a junk yard ecu the fuel pump primed and turned off as it should, but still will not start

Doug, Dan here, I’m no need of your help. I have a 1999 Jeep Cherokee Sport 6cyl 4.0. So the water pump went out. Simple enough, less than a week later I’m driving home when it stalls. I had just got in the Jeep, just warmed to operating temp. Since then it happens every time it warms up. Could it be the coolant temp sensor, could it be the crankshaft position sensor. I’m really strapped for cash, and could really use some help. Please get back to me.

I suddenly need to tale a trip to pull-a-part...😂

Hey man I have a 96 Tj with a 4.0 I only have High setting left for my heater, what should I change? Thanks 👊

smart

I took all my off and put anti seez inthe bolts LOL

Inhave a super rough idle and it clears up at about 2700 rpm and at idle the exhaust sounds like shit on idel as well. Amd when the air filter is off and you whack the throddle soumds like a toad is in there anyone have any ideas what yhis is?? Its nit the air semsor i tried that stayed the same

oil pressure sensor will cause it to run rough

My cam and crank position sensors constantly go out I can't stand it

ONLY USE OEM THROTTLE POSITION SENSORS!!! . napa, carquest, O-fucks..... all the same part.... all with same problem they arnt sealed... and get full of water . also with crank position sensor.... needs to be OEM the napa one worked for a while... but the magnet strength VS OEM is like 5x

I wouldn't bother getting the oil pressure sensor for this purpose unless you can find a low-mileage one you know will fit your engine. The 98 in particular used a different sensor from pretty much every other 4.0, and the one in the video looks like the aftermarket piece of crap that was on my ZJ when I got it. This sensor won't leave you walking, just with a sense of existential dread as your oil pressure gauge falsely shows zero, so it's worth it to get a new genuine Mopar sensor and probably never worry about it again.

Yessss, i did think wtf on that firing order!!. Shit happens. ;)

My 5.2 zj runs like shit out of nowhere and when it does run like shit I smell raw fuel so I'm thinking my map sensor is bad?

Most yards if you’re honest enough to ask about them we’ll just give them to you. Or at least charge you like 20 bucks for all that rather than per piece. You must’ve been at a LKQ.

11:53 Omicrons? You're watchin too much futurama its OM-RON

Buy a Mopar TPS sensor. The OEM ones are junk.

"Funkier than George Clinton"! !!!!!

Just literally 20 minutes/8 beers ago swapped the TPS from my 99 parts WJ into my 01 daily WJ and hopefully solved something I've been fighting for a week. Deep water on the road home and a coil strip and plugs later, I'm 160$ in and hopefully fixed. I'm on my 3rd WJ and it still still boggles me I can ford downstream with water over the headlights but a puddle takes me out for a week. 25 miles away from 200K.

Just literally 20 minutes/8 beers ago swapped the TPS from my 99 parts WJ into my 01 daily WJ and hopefully solved something I've been fighting for a week. Deep water on the road home and a coil strip and plugs later, I'm 160$ in and hopefully fixed. I'm on my 3rd WJ and it still still boggles me I can ford downstream with water over the headlights but a puddle takes me out for a week. 25 miles away from 200K.