Hood Vents/Louvers, Rain storm, problems...

[Redsnake]

Lots of posts about louvers and what potential problems it can solve (heat wise) and what it can cause (water on sensors wise) ... so I just installed a nice set of hood vents this past weekend and hadn't got around to making some drip pans yet. So last night we have a HUGE Thunderstorm and what-not... so as I get out in my XJ this am it fires right up, but the idle jumps up to ~ 2K rpms... slowing drops down to about 1K... but is idling fine. So I get ready to drive it out of my neighborhood and it's shifting horribly, hunting for idle and then finally it just stops moving... still idling ~ 1K but when I'm hitting the gas it's not moving. Almost like my transmission is slipping.

Turn around and idle it back home (1 block), pop the hood and get the air hose out and blow off the 3 sensors sitting around my throttle body. Unplugged and blew them out what I 'thought' was good and dry. Buttoned it back up and it drove better, but it was still shifting bad, missing out a bit and it didn't want to go into overdrive while driving down the street @ about 45mph...

I AM going to fab up some drip pans to help keep these sensors dry, but can anyone tell me which is the likely culprit (sensor) that I may have fried, or that needs to be thoroughly dried out and hopefully work right again? Could it be something on the passenger side of the engine that's causing these issues... perhaps the Coil Pack Wires got wet? I wouldn't think that'd control the transmission shifting, but I don't know everything... ha.

Appreciate the input all.

A couple pics for those who haven't seen them:

 

[Wayne Sihler]

TPS probably got wet.
I have a floor mat(house welcome mat) that I throw over my LeBaron vents.

 

[O-Gauge Steamer]

See? Drip Pans Are Your Best Friends... You have experienced exactly what I have been on about. I am sorry for your disaster but, good will come of it.

I also suspect the TPS as the culprit. They are rather notorious for misbehaving whilst wet.

Just remember to put a goodly amount of pitch into the pans for drainage. With your vent placement, I might suggest that the pans drain to the outboard sides.

 

[Redsnake]

^^ Agreed!

It was on my agenda to do, but thanks to the storm last night it's moved up to getting it done TODAY! I was also thinking that getting them to drain outboard was the best based on my vent location as well. That way they should miss the intake and all the sensors around the Throttle Body all together.

 

[Tim_MN]

Several XJ's in our local Jeep club have LeBaron hood vents and no drip pans. I have vents also, and no problems with rain, the car washes, or snow.

Dry out the TPS wire connector and use a generous amount of Dielectric grease inside the connector.

 

[Redsnake]

Several XJ's in our local Jeep club have LeBaron hood vents and no drip pans. I have vents also, and no problems with rain, the car washes, or snow.

Dry out the TPS wire connector and use a generous amount of Dielectric grease inside the connector.

I have heard this and read it on many posts... but unfortunately I'm not a lucky one and just one hard rain has caused havoc on my XJ and likely the TPS.

I am going to use Dielectric grease on all those sensors and also install a drip pan(s) to hopefully make sure this isn't an issue that arises again. I'm thankful I was home and could use my compressor to blow off the TPS to help out w/the drying process. Had I been out camping, traveling, etc... I'd have been in a bit of trouble.

 

[wheelinscott]

I have had louvers for 2+ years (lived in texas= big thunderstorms) now idaho(snow whatnot) and haven't had a problem with mine. I think Tim's idea will lead you on the right track...

 

[Redsnake]

OK... so I made a louver drain to help deflect any water f/the drivers side out to the outer edge of the hood/engine bay. Also, I bought a new TPS f/Napa and swapped it in. Now it's driving even WORSE than before. i also coated the wiring connections w/ Dielectric grease and not sure what to do now?? It's stuttering and surging and bucking while driving down the road.

Also, now my CEL codes are P0432 (which I've had for a long time and need to replace my pre-cats... so that's not the reason for this all-the-sudden change)
New codes:
P0123 TPS Sensor A Circuit High Input
P0121 TPS Sensor A Cirguit Range/Performance
P0122 TPS Low Input
P0700 Transmission Control System (MIL Request)


WTH is going on now?? Did I get a bad TPS f/ Napa? Did the Dielectric grease screw something up? Now what to try?? Ahhh... I figured this would be an easy fix, but now I'm starting to wonder...

 

[offroadordnance]

Could be oxidization on the TPS terms. Did you clean them mechanically before the dielectric grease?

 

[Redsnake]

I didn't clean the TPS Plug terminal before doing the dielectric grease treatment w putting the new TPS on. However I went back out, cleaned off some of the excess grease plugged it in & out a few times, reset my CEL codes and drove it some. It seemed better, almost like it was relearning, but I'm not sure it's 'fixed' yet. Hopefully it will continue to learn & get back to normal.

 

[offroadordnance]

You can use a dental pick or other sharp tool to close up the mating terminals on the OE pigtail. They tend to waller out and become oversized losing their bite through the non-conductive oxide that forms over the years.

 

[O-Gauge Steamer]

I didn't clean the TPS Plug terminal before doing the dielectric grease treatment w putting the new TPS on. However I went back out, cleaned off some of the excess grease plugged it in & out a few times, reset my CEL codes and drove it some. It seemed better, almost like it was relearning, but I'm not sure it's 'fixed' yet. Hopefully it will continue to learn & get back to normal.

IMO, you are on the right track. No two TPS Sensors are the same and the PCM wll need to relearn it. If you did not disconnect the battery prior to the installation of the TPS, you may consider it. Once the PCM loses the "maintain" voltage, it drops into learn mode.

Yes, yes, I know... They are learning all of the time. However, there is a big difference in how aggressively the PCM learns after power is completely removed.

 

[magimerlin]

Are the tps's on the newer XJ.'s adjustable? I only have Renix era jeeps. I know mine are adjustable. If the newer ones are to, did you adjust it to spec or did you just throw it in and go?

 

[Redsnake]

I don't know how adjustable it is... Two bolt in holes that have little to no adjustment. I've had vehicles where you could rotate the TPS to fine tune the voltages, but not sure I can on my '01.

I have not disconnected the battery as I HATE trying to reprogram my Alpine HU... but I may do it to promote a faster learning curve of my XJs computer.

 

[hubs97xj]

No, the OBDII TPS isn't adjustable. If you think the problem is the new TPS, bench test it with an analog ohmmeter (for that matter, test both TPS). If you think the problem is the grease, clean it all off and see if the problem persists; I have a plastics-safe contact cleaner that I use, and then I reassemble connections with a very small amount of Noalox on the pins and sockets.

edit; I'll ask just because I see people use the terms interchangeably, but did you use something like Oxgard or Noalox, or did you use dielectric grease?

 

[Redsnake]

edit; I'll ask just because I see people use the terms interchangeably, but did you use something like Oxgard or Noalox, or did you use dielectric grease?

Thanks for the info... I used Dielectric grease I purchased from NAPA.

Also as an update... after some time driving my XJ w/the new TPS it seems to be running as it should be now. Must be the computer has learned and not idle is good, no missing, transmission is shifting like it should, etc... so I won't complain.

I did however decide to remove the SPECTRE Intake as it just was a bit too noisy in the cabin for my tastes. Looks great, fits great, just wasn't exactly too my liking. I also installed a drip pan on the Drivers Side Louver out of some Aluminum, screws and spacers. Hasn't rained outside yet, but I think I'll give it a test w/the garden hose later this week to see how well it does preventing rain f/hitting my TPS.

Here's a couple pics. You can see w/there Spectre intake tubing hit/dented the drip pan, but that was remedied when I took off the Spectre and put back in my OE intake tube/filter box.

 

[Wayne Sihler]

I used cheap Walmart cookie sheets. Need to space farther down away from hood,,,,,,,not much "venting" going on that close......

 

[Redsnake]

I used cheap Walmart cookie sheets. Need to space farther down away from hood,,,,,,,not much "venting" going on that close......

There was no more room for the drip pans in my case w/the Spectre Intake in place... as you can see w/one of the pics it actually dented the drip pan when the hood was closed.

I replaced the Spectre w/the OE piece and granted it does give me more room so we'll see how this works and if I need more space, then more space I'll create.

 

[O-Gauge Steamer]

Yoy would be amazed at just how little clearance is required for the heat to vent. IMO, if you have not actually done this mod then, your opinion is not worth very much...

There is very little clearance between the factory flex joint and the underside of the hood. In my case, even less as the TB is up and to the back from stock due to the Supercharger. So comments like "they are too close to the hood" are not helpful in any way. Go look for yourself and see just how little room there is.

We are stuck with the clearaances we have all due to the XJ having been originally designed around the 2.5L I-4 and the 2.8L V-6. These engines are small. Jeep had to knock a hole in the firewall and offset the engine in the bay just to get the 4.0L under the hood. If it were centered, there would not be clearance for the manifolds.

Inre Redsnake's pans, I might have stopped them in front a bit more than he did (not an issue, just an opinion) and would have made the bends a set of hard 90 degree ones to increase the regidity of the pans.

Otherwise, for a first attempt, they are not bad. And, they are functional for good measure.

 

[Redsnake]

Thanks... I'm sure mine could be made better for sure, but I was kinda in a crunch looking for some 'aluminum' or metal I could use at the hardware store. I'm sure their are a few items that could be used and I may re-design them again, but hopefully these will work for now.

All that is needed, is something to divert the rain water away f/the TPS ... for the most part. Mine won't rust and I'm pretty sure will drain the water away is needed.


o-gauge... can you elaborate a bit on this

"Inre Redsnake's pans, I might have stopped them in front a bit more than he did (not an issue, just an opinion) and would have made the bends a set of hard 90 degree ones"

Just to give me a better visual of what you're saying as I may try and incorporate that in my 'next' version of drip pans...