A Couple (Probably Dumb) 2.9 Questions

Trepat · Jan 30, 2018

Hey all,

I have a 1990 2.9 Ranger, which I've been enjoying a lot. Picked it up with only 185,000km on the ticker, and the body is in pretty good shape (for where I live anyway).

It's already had the leaking valve cover seals replaced (by a garage), and other than that I've just done really basic stuff like change the transmission fluid and oil.

I've always liked cars, but never really worked on them which was one of the reasons for this truck. I wanted to be able to have a vehicle I can learn on.

I'm wanting to refresh some parts, and one of the parts I wanted to put on is an O2 sensor.

But, I noticed on RockAuto that there's 3 and 4 wire sensors. It's the middle of winter here so I haven't crawled under the truck yet, but what should I look for on the current O2 sensor? Will I be able to see 3 or 4 wires coming out of it? I'd rather not pull it off if possible, as this is my daily.

Also, I was going to put new plug wires on as some of the current ones are pretty hashed. I saw it wasn't too much more money for wires and a cap+rotor, so I was thinking of doing it all at once.

Question is, I've heard changing the cap+rotor can change the timing. Is there a way to replace a cap+rotor without having to re-time the engine?

Finally, a question about cleaning.

Previous owner drove a long time with leaking valve cover seals, so the engine, engine bay, and transmission are covered in old oil. I tried some Gunk engine cleaner in the summer, and it didn't do much. What's a safe way to give this engine bay a deep-clean, or should I let a pro do it?

Thanks in advance.

wildbill23c · Jan 30, 2018

If you crawl under the truck and look at the current o2 sensor you'll see a 2 or 3 wire connector coming off of it, it will be quite obvious.

If you are going to do a tuneup do it right or don't bother. Cap, rotor, plugs, and wires all at the same time. And no, changing the cap & rotor doesn't do anything to the timing unless you start spinning the rotor around with your hand, simply pull the old rotor off, put the new one on, and the cap just slips on can't really screw that up...ok well the parts store can if they sell you the cap and rotor for a Full size V8 Bronco LOL....wasn't a Bronco it was a Jeep but my local Autozone did that to me, didn't realize or really pay attention till it died on me on the freeway one afternoon because the rotor disintegrated due to being the wrong one. Gotta pay attention to those parts grabbers, they most likely have no damn clue what they are doing or what those parts even do.

Engine degreaser with the engine warm will work very well, just be careful where you spray water you don't want to get it in the intake, or into the distributor.

Trepat · Jan 31, 2018

wildbill23c said:
If you crawl under the truck and look at the current o2 sensor you'll see a 2 or 3 wire connector coming off of it, it will be quite obvious.

If you are going to do a tuneup do it right or don't bother. Cap, rotor, plugs, and wires all at the same time. And no, changing the cap & rotor doesn't do anything to the timing unless you start spinning the rotor around with your hand, simply pull the old rotor off, put the new one on, and the cap just slips on can't really screw that up...ok well the parts store can if they sell you the cap and rotor for a Full size V8 Bronco LOL....wasn't a Bronco it was a Jeep but my local Autozone did that to me, didn't realize or really pay attention till it died on me on the freeway one afternoon because the rotor disintegrated due to being the wrong one. Gotta pay attention to those parts grabbers, they most likely have no damn clue what they are doing or what those parts even do.

Engine degreaser with the engine warm will work very well, just be careful where you spray water you don't want to get it in the intake, or into the distributor.

Thanks for the info, it's much appreciated. I'm getting the parts from RockAuto, no parts-stores near me (and the ones in the city charge exorbitant prices).

I did the plugs about 2500km ago, which is when I noticed the plug wires were hashed. Just haven't had time or money for the truck. Should I replace the plugs again when doing cap/rotor/wires?

I'll crawl under the truck to see how many wires are coming out of the O2 sensor.

Engine degreaser will probably have to wait until spring where I am - it was a frosty -34 Celsius this morning. Not having a garage sucks big time.

fastpakr · Jan 31, 2018

Trepat said:
Engine degreaser will probably have to wait until spring where I am - it was a frosty -34 Celsius this morning. Not having a garage sucks big time.

No oxygen sensor is worth crawling under a truck at that temperature!

killswitch21 · Jan 31, 2018

+1 to physically look at your o2 sensor. As for cap and rotor, just be very careful not to spin the rotor when you change the cap. (worth checking the timing with a light before and after to make sure its at 10 degrees BTDC)
New plugs and wires really seemed to wake the truck up. (Before the truck hated doing 70 on the freeway)

For cleaning engine bays. I've had luck with spraying simple green onto a warm engine, letting it sit for awhile and spraying it off with water. (careful not to blast sensors or fragile stuff) although tough caked on stuff will still need a wire brush.

I've been rebuilding a 2.9 myself. So I'll throw out some of the issues I've run into with it.

Check for coolant leaks, my 90 2.9 would start leaking small amounts off coolant, from where the plastic of the radiator met the metal, but only when it was warmed up.

If you smell fuel, check in the engine bay for anything obvious.. but more than likely its your fuel filler neck. The clamp on mine seemed to tear into the hose allowing it to leak if I am refueling slowly or right when it tops off.

Change all fluids, I think the axle fluid and transfer case fluid in mine was original.

Check your fan blade, my stock plastic one was cracked up really bad around the base of the blade. I replaced it with a metal one, plus I replaced the radiator, thermostat, and water pump all at once.

If your temp gauge doesn't go up more than like a 1/4, replace the temp sender and temp sensor. I did and my temp gauge reads as it should now. no need for a mechanical gauge like many on here suggest, albeit a mechanical gauge is more accurate.

if its manual transmission, mine had no bushings left, and also replacing the freeze plugs in the trans stopped my slow leak.

Not really maintenance based, but I replaced the tape deck with a CD player and picked up new front speakers as well. My stock rear speakers were blown, but my fronts were fine. So I put the new ones in the front, and built simple boxes to mount the OEM front speakers in the back of my truck. The front and rear speakers use the same connector so it was plug and play and made a huge difference in my trucks audio system for fairly cheap.

Trepat · Jan 31, 2018

fastpakr said:
No oxygen sensor is worth crawling under a truck at that temperature!

I am going to agree with you there, sometimes I wonder why I live here.

killswitch21 said:
+1 to physically look at your o2 sensor. As for cap and rotor, just be very careful not to spin the rotor when you change the cap. (worth checking the timing with a light before and after to make sure its at 10 degrees BTDC)
New plugs and wires really seemed to wake the truck up. (Before the truck hated doing 70 on the freeway)

For cleaning engine bays. I've had luck with spraying simple green onto a warm engine, letting it sit for awhile and spraying it off with water. (careful not to blast sensors or fragile stuff) although tough caked on stuff will still need a wire brush.

I've been rebuilding a 2.9 myself. So I'll throw out some of the issues I've run into with it.

Check for coolant leaks, my 90 2.9 would start leaking small amounts off coolant, from where the plastic of the radiator met the metal, but only when it was warmed up.

If you smell fuel, check in the engine bay for anything obvious.. but more than likely its your fuel filler neck. The clamp on mine seemed to tear into the hose allowing it to leak if I am refueling slowly or right when it tops off.

Change all fluids, I think the axle fluid and transfer case fluid in mine was original.

Check your fan blade, my stock plastic one was cracked up really bad around the base of the blade. I replaced it with a metal one, plus I replaced the radiator, thermostat, and water pump all at once.

If your temp gauge doesn't go up more than like a 1/4, replace the temp sender and temp sensor. I did and my temp gauge reads as it should now. no need for a mechanical gauge like many on here suggest, albeit a mechanical gauge is more accurate.

if its manual transmission, mine had no bushings left, and also replacing the freeze plugs in the trans stopped my slow leak.

Not really maintenance based, but I replaced the tape deck with a CD player and picked up new front speakers as well. My stock rear speakers were blown, but my fronts were fine. So I put the new ones in the front, and built simple boxes to mount the OEM front speakers in the back of my truck. The front and rear speakers use the same connector so it was plug and play and made a huge difference in my trucks audio system for fairly cheap.

Thanks for all the advice, I actually have some of the exact issues you mentioned.

I can smell coolant sometimes after the truck is warmed up, I had checked around but couldn't see anything. I'm going to check where you found your leak to see if that's the problem spot.

Thankfully I haven't smelled any fuel, but I'll keep an eye out for that.

My temp gauge is screwy too, my plan is to change those sensors. Did you just change the coolant sensors?

Fluids are all getting a change in spring (the ones that haven't been changed).

I do have a manual transmission, the FM132. Is it a big job to replace the bearings?

killswitch21 · Feb 1, 2018

Trepat said:
I am going to agree with you there, sometimes I wonder why I live here.

Thanks for all the advice, I actually have some of the exact issues you mentioned.

I can smell coolant sometimes after the truck is warmed up, I had checked around but couldn't see anything. I'm going to check where you found your leak to see if that's the problem spot.

Thankfully I haven't smelled any fuel, but I'll keep an eye out for that.

My temp gauge is screwy too, my plan is to change those sensors. Did you just change the coolant sensors?

Fluids are all getting a change in spring (the ones that haven't been changed).

I do have a manual transmission, the FM132. Is it a big job to replace the bearings?

Yeah, Same here. I would smell coolant sometimes when it was warmed up, but I couldn't pinpoint it. I finally found it by just watching it for like 10 minutes while it ran.

Well since I had found the leak, and the fan was cracked up so bad. I did the radiator, fan, fan clutch, thermostat, Water pump, and the 2 coolant sensors at the same time. I believe they are called the temp switch and the temp sensor/sender. IIRC the single connector switch is actually what sends the signal to the gauge on the dash, and the 2 pin sensor is what the ECM uses to know the Temp.

You would probably be able to tell if you needed to change the bushings in the Transmission. I had no bushings in there so there was a ton of slop in the shifter, and I could lift the shifter about 1.5" up before there was any resistance. Shifting was quite sloppy too unless I lifted it the 1.5" and then shifted. If you follow the link below, its an outline of the bushings I'm referring to.

http://www.therangerstation.com/how-to/transmission-transfer-case-driveshaft/shifter-bushing-replacement/

wildbill23c · Feb 1, 2018

killswitch21 said:
+1 to physically look at your o2 sensor. As for cap and rotor, just be very careful not to spin the rotor when you change the cap. (worth checking the timing with a light before and after to make sure its at 10 degrees BTDC)
New plugs and wires really seemed to wake the truck up. (Before the truck hated doing 70 on the freeway)

For cleaning engine bays. I've had luck with spraying simple green onto a warm engine, letting it sit for awhile and spraying it off with water. (careful not to blast sensors or fragile stuff) although tough caked on stuff will still need a wire brush.

I've been rebuilding a 2.9 myself. So I'll throw out some of the issues I've run into with it.

Check for coolant leaks, my 90 2.9 would start leaking small amounts off coolant, from where the plastic of the radiator met the metal, but only when it was warmed up.

If you smell fuel, check in the engine bay for anything obvious.. but more than likely its your fuel filler neck. The clamp on mine seemed to tear into the hose allowing it to leak if I am refueling slowly or right when it tops off.

Change all fluids, I think the axle fluid and transfer case fluid in mine was original.

Check your fan blade, my stock plastic one was cracked up really bad around the base of the blade. I replaced it with a metal one, plus I replaced the radiator, thermostat, and water pump all at once.

If your temp gauge doesn't go up more than like a 1/4, replace the temp sender and temp sensor. I did and my temp gauge reads as it should now. no need for a mechanical gauge like many on here suggest, albeit a mechanical gauge is more accurate.

if its manual transmission, mine had no bushings left, and also replacing the freeze plugs in the trans stopped my slow leak.

Not really maintenance based, but I replaced the tape deck with a CD player and picked up new front speakers as well. My stock rear speakers were blown, but my fronts were fine. So I put the new ones in the front, and built simple boxes to mount the OEM front speakers in the back of my truck. The front and rear speakers use the same connector so it was plug and play and made a huge difference in my trucks audio system for fairly cheap.

If you smell fuel it could be coming from the stupid fuel reservoir under the driver's side in the frame rail just about right under the door. Just had that problem with my 88 B2.

Also, as far as replacing the plugs again, if you just did them, just finish up the tune up with a new cap, rotor, and wires.

Michael88STX · Feb 20, 2018

wildbill23c said:
If you smell fuel it could be coming from the stupid fuel reservoir under the driver's side in the frame rail just about right under the door. Just had that problem with my 88 B2.

Also, as far as replacing the plugs again, if you just did them, just finish up the tune up with a new cap, rotor, and wires.

I agree completely. If you've just replaced the plugs abt 2500 miles ago there is absolutely no reason to replace them again that soon. I would though, just to be safe, take them each out individually and check for signs of damage since you'll be under the hood in the same area. If any of them look bad then you need to make a note as to which cylinder it is that that one plug came out of and figure out what caused it. Hopefully you do not have any problems though. Spark plugs aren't the type of thing that need changing on a regular basis. I've seen guys go over 120k miles on the same plugs. I personally wouldn't go too long (no more than about 20k-30k miles for copper tip plugs and about 50k-80k miles for platinum or iridium tip plugs is my personal preference) without a change because its more risk of something going wrong.

Here is a refence on Angie's List if you want to read up on more on replacing plugs: https://www.angieslist.com/articles/how-often-should-i-change-my-spark-plugs.htm

Hope I was able to help!

A Couple (Probably Dumb) 2.9 Questions

Trepat

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wildbill23c

Well-Known Member

Trepat

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fastpakr

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killswitch21

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Trepat

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killswitch21

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wildbill23c

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Michael88STX

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