ddub

I had 18-19mpg with mostly city driving before AND after the mod. I saw no difference in mileage.

dsmdriver

iTrader: (3)

I did this a much easier way, but many people will probably think I'm crazy.

I just dropped a 1 1/2" drywall screw in the top of the TB. This is wide enough that it can't go into the TB, and also wide enough that the rubber hose "grabs" it, creating a good seal. It's long enough that it can't go upwards and make it around the bend if it ever came loose.

Literally: I took off the upper hose, dropped in the screw, pushed the hose back on.

It's been there for three weeks and hasn't moved a millimeter, and it's clearly blocking the flow.

93rdcurrent

Ooooohhhh me likey the way you thinky. I actually think I am going to install a bypass valve with an on/off switch. I was thinking about this since I am going to have to reinstall it today anyway so I might as well go ahead and muss with doing it the right way from the start. I'll try to take a pic for you guys to see. I may also find myself driving back to Spokane from time to time in the winter and don't want to take the time to undo it everytime. Think the dealer will give me any grief if I explain to the the problems I was having and why I did it?

93rdcurrent

OK I went down and bought a bypass valve so I can shut the flow off to the throttle when I want and to turn it back on when I need to. Anyone know if the upper or lower coolant hose is the coolant feed in hose? I do kinda need to know which one I am needing to throw my valve on.

Anyone with the technical service manual? Please help!

93rdcurrent

Put it back to stock because I'm planning on taking it to the dealer this week and I decided to clean out the throttle body at the same time with carb cleaner... I think I killed the O2 sensor... The car would start and then stall out immediately. I started to get freaked! I mean really freaked out!!!! I could keep the car running while I was spraying in the carb cleaner but as soon as I would stop it would die. I figured that this was due to the MAF sensor which I think is located on the intake hose right before it gets to the throttle body.

So after I had sprayed like a quarter of the can of carb cleaner I decided it should be clean enough to put everything back together and see if it would stay running. It did! Suddenly I wasn't as freaked out. It was idling and continued to run with no major issues. Then I decided to give it a couple of runs through the neighborhood with some redlines (normal driving conditions) and some putting around to see how responsive or lack thereof it would be. Everything seemed pretty smooth and it was actually feeling smoother than it has in a while... then I got to a light and realized that the car was idling at about 1.5k rpms! Yes, that's higher than normal. It would eventually go down to 1k rpms and just about the time it would hit the typical 850 or 750 rpms it would shoot up to either 1.5k or 1.25k for about a second and then drop back down. I'm not going to say anything but I am going to clean the coolant off the engine and just see what he dealer comes up with. I'll let you know.

93rdcurrent

OK I have an update on my crappy mpg I will update this in a couple of threads since they are related to this. I had done the DIY throttle body bypass and since I was taking the car into the dealer this week I decided to put it back to stock. I didn't let the car cool down enough and sprayed coolant all over the interior of the engine compartment getting in the throttle body, the intake hose and generally just about everywhere except into the intake itself fortunately! I put everything back together after cleaning the throttle body and the intake out with carb cleaner.

The car seemed to be idling a bit high but seemed to be ok. I took it out for a test run with some redline runs and some cruise around town driving conditions to see how it was running. I get to a light and notice my car is idling at 1.5k rpms which is higher than normal after it's warmed up. It did slowly go back down to normal or 850 rpms but shot right back up and did the hunting idle thing. After a 10 min run with no change I go back home and give up for the night (at least she's running right I didn't kill anything.)

The next day I go over to Zoom44's to use his Hymee tool since a CEL was thrown and I could get the codes from him. We get number one code as MAF=low input... that tells me what I suspected which was the MAF was either dirty or damaged. We bust out the carb cleaner spray it down real good and put it back in. We clear the codes and start it up. No codes!!! Idle is perfect just like new. We drive it around and no issue. I was just about 60% in the gas tank (yes the Hymee tool tells you that too) and I had 73 miles since last fill up! Yes my mileage has been that bad. I have gone 25 miles since Monday night and I have used less than 1/8th of a tank!!!!! :wow: I didn't actually expect to see mpg (and most likely hp) gain from this.

I think mines been dirty for a long time and has been slowly getting dirtier until we come to today and the sudden change in my cars gas mileage. Maybe some of the other people having gas mileage issues could check this out since I wasn't throwing CELs before and I have taken it into the dealership for mpg issues a number of times!

I will keep everyone updated on my next fill-ups to see if this continues.

dgrx8

is there any way i can clean the inside of the throttle body? i didn't cap the ends til several thousand miles later...
compressed air?? any suggestions??

dgrx8

ok.. sort of answered my own question...
http://www.lake-link.com/dodge/truck...?TruckTipID=16

i'm wondering now if those that have experienced power loss due to dirty MAF's have checked their TB's along w/ the inlet tube? it seems everyone is cleaning the tube & MAF but there could be buildup in the TB as well...

93rdcurrent

My tb was dirty as well as the intake tube and MAF sensor. I was already cleaning the tb with carb cleaner. Consider though that I have 40+k miles on my car too.

Jaguar_MBA

I did this Mod this morning. I bought a 3/8" brass barb splice from Home depot. I went to three different auto parts store trying to find any brass splice barbs....to no avail. Anyway The 3/8" barb is very tight but it sure won't ever leak. I placed worm gear clamps over each end of the barb to. I drove the car around for ~ 5 minutes and the coolant line was very hot but the TB was pretty cool still.....nice.

Currently I have electrical tape covering the TB's upper hose connection point.

I do suggest getting 5/16" Splice Barb (Brass) if you can find one.....I could not find one.

Also when I disconnected the coolant lines from the TB this morning I did not loose any coolant....must drained all down during the night.

In order to do this you also need to remove all of the accordian intake tube and the rubber tube connected to the Metal TB's housing.

Nice easy Mod.

zoom44

ld suggest putting a rag in the accordian tube and in the throttle body openings just in case you get some coolant spray

93rdcurrent

Good suggestion. I should've thought of it myself. I also should've just waited until it cooled down. Do you think I should replace the spilled coolant?

dgrx8

never hurts to top it off...

davefzr

So are you just rerouting the coolant elsewhere or is the line plugged and the hose is fed outside of it's normal route? Me no get this mod..... I can tune the Int-x but cant figure this out.. haha

Anyway. If someone could explain it I would appreciate it.

93rdcurrent

It's just as it sounds... don't quote me for certain as to which is the Feed and Drain line but the concept works the same and I think this is accurate but I won't know for a little bit longer and no one answered my question... Bueller... Bueller... anyways, it seems that the line coming from underneath the throttle body is the feed line and the one on top of the throttle body is the drain line. If you disconnect both and hook them together as recommended you would have a connection that goes from feed to drain but doesn't do it through the throttle body but really goes through the hose for no reason.

Here's my recommendation... take a on/off valve and intercept the feed line so that you can shut it off in the higher temp days, track day, or whenever your fancy strikes... but if you find yourself driving through a cold mountain pass (we have plenty of those around my parts) then you can switch it back on and have no problems with condensation in the throttle body. Just a suggestion... like waiting until the car has cooled down completely before starting the mod.

93rdcurrent

It's just as it sounds... don't quote me for certain as to which is the Feed and Drain line but the concept works the same and I think this is accurate but I won't know for a little bit longer and no one answered my question... Bueller... Bueller... anyways, it seems that the line coming from underneath the throttle body is the feed line and the one on top of the throttle body is the drain line. If you disconnect both and hook them together as recommended you would have a connection that goes from feed to drain but doesn't do it through the throttle body but really goes through the hose for no reason.

Here's my recommendation... take a on/off valve and intercept the feed line so that you can shut it off in the higher temp days, track day, or whenever your fancy strikes... but if you find yourself driving through a cold mountain pass (we have plenty of those around my parts) then you can switch it back on and have no problems with condensation in the throttle body. Just a suggestion... like waiting until the car has cooled down completely before starting the mod.

dgrx8

i have a question......
would there be a way to further cool our bypassed TB??
perhaps we can fill the plugged TB w/ coolant or water wetter... would that make any significant temperature changes?

toxin440

just did the throttle body bypass mod on my RX8... took me about an hour and a half, but consider I did this with only a screwdriver and in a hotel parking lot (yes I live in a hotel - work related but yay i dont pay for it!)

I let the car cool down for the most part when i started it was a bit hot to the touch, but by the time I figured everything out it was cool, when I disconnected the coolant lines that run thru the throttle body I got no spray or leaking the toughest part was the underside "feed" line, for the life of me I coulndt get it off the right way so I just cut the tube. I got the top one off the right way, i need to get a large nipple or something to cover it and make it look nice instead of just some big metal hole.

Havent taken it for a spin yet, but once i secured everything and put my intake back together I fired up the car to check for leaks did a few revs to 9K to warm it up (and just to hear the sweetness of my rotary and the RP supercat I have) mmmm

No leaks, I did notice that the metal throttle body stayed cool as a cucumber the whole time even after the rest of the engine was nice and toasty. The only other thing I can say now is DAMN my fingers hurt

93rdcurrent

You don't want to cool it any further since the throttle body may get condensation under cooling conditions. This really is enough unless you have a turbo. Then I would recommend an intercooler to cool down the air coming in.

Razz1

I used a polyethlene barbed tube 5/16".

Any problem with using this?

dgrx8

nah... that's cool

mikeschaefer

I just did this and I figured I would reiterate some of the points made earlier because even though I read the entire thread I made some mistakes.

1) Make sure you let it cool first. I sprayed myself with hot coolant and that wasn't fun.
2) I decided to cut the longer stock line and just put a coupler between the two stock tubes over next to the alternator toward the passenger side. It just seemed to make more sense to do this, especially if you know you won't need to go back to stock configuration.
3) With that said you definitely want the 5/16" coupler for the stock hoses! I couldn't find one and went with 3/8". It is on but it is not as secure as I would like and I am going to be changing that as soon as I find a 5/16". The stock hose clamps barely go over the tube on the 3/8" coupler. I would definitely use screw type clamps with a 5/16" coupler though to get the best seal.
4) I had 3/8" rubber caps lying around so I put them on the throttle body holes and secured them with hose clamps. I was worried about corrosion inside the throttle body.
5) I don't think making the throttle body any cooler is necessary. By doing this mod the temp of the TB already drops nearly 100 degrees when driving around.

toxin440

you said it's not necessary but you also said the temp drops by over 100 degrees, that HAS to be good for the incoming air... im kinda confused by that statement

Razz1

He has no proof on temperture.

However I drove an hour from 80 degrees to 105. Then I joined the club meet and we went up the mountain. After anther hour we stopped and compared TB.

You can touch mine. We tried to toch the other throttle bodies. They were scalding hot. You touch you get burned. Difference is several degrees, 100, I don't know, but enough to make a huge difference.

I would say we get 1 1/2 HP or more from this. Plus a massive decrease in heat exhaustion, which means very little loss in power at extreme tempertures.

Jaguar_MBA

I agree the difference in temperature is amazing. 1.5HP that is not bad, not bad at all.