cruiser54 Posted August 3, 2013 Share Posted August 3, 2013 I simply adjusted it by screwing that allen wrench screw off the TB. I'm guessing now that that was a bad idea and shall do everything according to what you recommend. And thank you for the pictures. How many lines come off the air intake box? And the BA10 was in them till about mid 89. Mine was made in febuary. Hence the ba10 Cruiser’s Renix Throttle Body Butterfly Adjustment Okay. Let's start from scratch. First off, that's not an idle adjustment screw. It's a throttle butterfly stop screw. It's purpose is to allow the butterfly to be as close to completely closed as it can be without binding or wearing into the throttle body. It was never intended to be adjusted in the field. But, Uncle Bob didn’t know that, did he? Engine off. Back off the butterfly stop screw with a 3/32” allen wrench until the butterfly is completely closed. Now. turn the screw in until the FAINTEST movement of the butterfly opening is detected. This can be done more easily with the throttle body removed. If you remove the throttle body, be sure to replace the gasket underneath it after thoroughly cleaning the old one off. Revised 07/07/2012 Link to comment Share on other sites More sharing options...
Knucklehead97 Posted August 3, 2013 Author Share Posted August 3, 2013 Probably shouldve read through all the tips before attempting anything.. thanks. I've got to order the vacuum harness's. Hopefully will get to install them by next week end. Is there anything else I should pick up? I can't get the o2 sensor yet. Link to comment Share on other sites More sharing options...
carnuck Posted September 1, 2013 Share Posted September 1, 2013 MAP sensor hose is VERY important! They get clogged up from backwash in the throttle body too. Cleaning it with TBI cleaner (the hose) and the CCV tube as well as the throttle body and making sure the intake bolts are tight is important too. The vacuum ball behind the bumper cracks after minor accidents and the vacuum leak messes with the fuel economy. I got 17 mpg with a canopy, 6 tires, towbar, tool box, shop jack and 2 adults while driving nearly to CA border from Seattle and towing an AMC Eagle SX4 back I got 14. That was with 4.0L/AW4/NP242 and 235/75/15 tires and 3.73 gears lifted 5 1/2" (SOA rear). Before we left I cleaned the throttlebody, ran a bottle of Amsoil PI (performance Improver) part way through 2 days before the trip. Now with 33/9.50/15s, it should have 4.10 gears. I dropped to 15 mpg and 200 miles a tank. I'll check it again monday/tuesday because I have to deliver an IH 304/auto trans and freeway cruise (2 adults, big dog and toolbox with canopy) I discovered the MAP hose was part way out of the throttle body (heard hissing yesterday and plugged it back in) With a metric tonne of gravel (2280 lbs) Without Link to comment Share on other sites More sharing options...
carnuck Posted September 1, 2013 Share Posted September 1, 2013 PS: Renix VS HO They use the same cam, but it's timed differently. They retarded the cam to reduce the amount of air/fuel charge in the cylinders so they could eliminate the EGR valve. It also resulted in higher horsepower output at a higher RPM because of the change of torque curve. That is why the Renix got the 0.70 O/D and HO got the 0.75 because it didn't have quite as much oomph off the line until the RPMs picked up. They also went with a larger throttlebody and bigger injectors, which is why a Renix will run like a scalded cat with HO injectors, but won't pass as many gas stations! The HO head is good for only 25 HP boost in and of itself. Link to comment Share on other sites More sharing options...
cruiser54 Posted September 1, 2013 Share Posted September 1, 2013 PS: Renix VS HO They use the same cam, but it's timed differently. They retarded the cam to reduce the amount of air/fuel charge in the cylinders so they could eliminate the EGR valve. It also resulted in higher horsepower output at a higher RPM because of the change of torque curve. That is why the Renix got the 0.70 O/D and HO got the 0.75 because it didn't have quite as much oomph off the line until the RPMs picked up. They also went with a larger throttlebody and bigger injectors, which is why a Renix will run like a scalded cat with HO injectors, but won't pass as many gas stations! The HO head is good for only 25 HP boost in and of itself. Look at it this way. The 90 Renix made 182 HP. The 91 and later HOs made 190 HP. So, the HO head ain't good for 25 HP. The biggest difference in HP was the 58mm throttle body on the HO versus 52MM for the Renix and the fact that the HO had a better designed exhaust manifold. 8HP, and only at higher RPMs, without a bit of extra torque. Link to comment Share on other sites More sharing options...
Knucklehead97 Posted September 2, 2013 Author Share Posted September 2, 2013 Ill clean the map sensor hose. And can I buy a new vacuum bottle for behind the bumper? Changed all hoses except the MAP (was told the hose was fine. Just got the rotted bushings changed.) And I'm still only gwtting about 13 a gallon. Link to comment Share on other sites More sharing options...
HOrnbrod Posted September 2, 2013 Share Posted September 2, 2013 And can I buy a new vacuum bottle for behind the bumper? Locating the vacuum reservoir behind the front bumper, exposed to the weather and requiring extra vacuum hose was just a stupid place to put it IMO. Relocate it inside the engine compartment in a location of your choice and use a vacuum reservoir from any vehicle that will fit the location well. It cuts down the chances of vacuum leaks and makes troubleshooting easier. Here's how I did it - there are many other ways to do it. http://comancheclub.com/topic/16154-vacuum-reservoir-relocation/?hl=vacuum Link to comment Share on other sites More sharing options...
carnuck Posted September 2, 2013 Share Posted September 2, 2013 You can get the universal vacuum ball from Napa for about $17 and it fits well under the hood Link to comment Share on other sites More sharing options...
Rockfrog Posted September 2, 2013 Share Posted September 2, 2013 I put mine here ... upper left in the picture. Also replaced my MAP and Fuel pressure regulator Vacuum lines with Brake line (still the leaking plastic in the pictures), fit the end fittings much more securely and won't crack or melt in my lifetime. Have you tried cleanning the IAT (Inlet Air Temp sensor)? checked the ECU's coolant temp sensor (lower driver side of manifold)? MAP? And as mentioned the O2 sensor. How is you're EGR system functioning? Mine was fubar so it was deleted (which also happens to be the bulk of the vacuum harness). Last trip was a 21mpg avg over 500km's Yes, I still need to replumb the EVAP cannister as well Link to comment Share on other sites More sharing options...
Knucklehead97 Posted September 2, 2013 Author Share Posted September 2, 2013 I put mine here ... upper left in the picture. Also replaced my MAP and Fuel pressure regulator Vacuum lines with Brake line (still the leaking plastic in the pictures), fit the end fittings much more securely and won't crack or melt in my lifetime. Have you tried cleanning the IAT (Inlet Air Temp sensor)? checked the ECU's coolant temp sensor (lower driver side of manifold)? MAP? And as mentioned the O2 sensor.How is you're EGR system functioning? Mine was fubar so it was deleted (which also happens to be the bulk of the vacuum harness). Last trip was a 21mpg avg over 500km's Yes, I still need to replumb the EVAP cannister as well tell me where they are and how to check them and I will :D I really need better mileage haha Link to comment Share on other sites More sharing options...
Rockfrog Posted September 2, 2013 Share Posted September 2, 2013 IAT - located behind the throttle body in my picture, has two black wires coming from it and looks like a pipe plug in the manifold. MAP - located on the firewall just above the manifold, has the green plug going to it and a vacuum line (you just replaced part of it's vacuum line) ECT - located on the lower drivers side of the block, just below the exhaust manifold. EGR - is actually a series of parts ... EGR solenoid, EGR transducer, EGR valve and the associated vacuum hosing. I don't really see this one affecting mileage as much as the others. here's a good site with pictures of locations and how to test. http://www.lunghd.com/Tech_Articles/Engine/Basic_Sensors_Diagnostics.htm between this and cruiser54's info you should be set. Link to comment Share on other sites More sharing options...
Knucklehead97 Posted September 3, 2013 Author Share Posted September 3, 2013 Looks like I'm gonna be having fun with sensor testing when I get home... great :D thanks man that site really is thorough enough to get things tested hopefully easily Link to comment Share on other sites More sharing options...
swamprat Posted September 3, 2013 Share Posted September 3, 2013 are your tires properly inflated? last time you changed oils? i average about 20-22 in my mj, the key is maintenance. Link to comment Share on other sites More sharing options...
Knucklehead97 Posted September 5, 2013 Author Share Posted September 5, 2013 I have to add oil weekly thanks to a rms leak that I havnt had the time to fix. My tires are all brand new. I was thinking about getting new plugs, wires, rotor, and cap. Should I? Link to comment Share on other sites More sharing options...
cruiser54 Posted September 5, 2013 Share Posted September 5, 2013 I have to add oil weekly thanks to a rms leak that I havnt had the time to fix. My tires are all brand new. I was thinking about getting new plugs, wires, rotor, and cap. Should I? Absolutely!! NGK plugs, Belden wires, Premium cap and rotor. all at Napa. And, while you're under the hood, check your leak this way to be sure of it's origin: I'd be looking up ABOVE first, and VERIFYING the source of the oil leak YOURSELF. Everybody, who doesn't own or have to pay for or perform your vehicle repairs, loves to poke their noggin UNDER the Jeep and come out bearing the false bad news that your RMS is leaking. Many mechanics, friends, people on Jeep forums who can’t see your Jeep from where they’re at, and good old Uncle Bob seem to enjoy telling you it’s the rear main seal. Has a catastrophic ring to it, doesn’t it? A simple leak at the back of the valve cover or other source could produce the same symptoms. You don’t need to be a mechanic to figure this out. If you have good eyesight and a dim flashlight, you’re good to go on your own. Don't jump on the RMS/oil pan gasket bandwagon right off the bat. Almost any oil leak on your 4.0 is gonna drip from the RMS area for two simple reasons. First off, the engine sits nose-up and any oil will run back to the RMS area. Secondly, the RMS area is also the lowest point on the engine. Simple physics and the old plumber's adage apply here. "$hit flows downhill". Valve cover gasket, oil pressure sending unit, oil filter adapter seals and distributor gasket, in that order, have to be eliminated as possibilities first. Revised 02-26-2013 Link to comment Share on other sites More sharing options...
Knucklehead97 Posted September 5, 2013 Author Share Posted September 5, 2013 I've already checked off the valve cover, and oil filter (PO changed valve cover gasket. I changed the oil filter the other day.) Is the oil filter adapter seals a different thing? And wgeres the oil pressure sending unit at? I also didn't know the distributor had oil running through it... and how much will all of the wires and plugs and everything run me? Looks like I'm deffinetely spending my bumper and rollbar fund on getting my MPG up. Link to comment Share on other sites More sharing options...
Rockfrog Posted September 5, 2013 Share Posted September 5, 2013 The distributor doesn't have oil running through it, it's running under it lubricating where the drive gear meshes with the cam. The Oil Filter adapter has three o-rings inside it, when they go it's a major leak point. the Oil pressure sender is just to the left of the Oil Filter adapter. and just because the PO changed the VC doesn't mean it may not be leaking .... usually it leaks from the back as the back three bolts have loosened (or may have been missed during install, especially the last one closest to the firewall ... the one you have to feel for to find. If you don't see a blue rubber gasket under the Valve cover ... it's probably leaking ... the 4.0 is notorious for VC leaks, especially the earlier years. Get some engine cleaner, clean the motor, especially the passenger side, then check it after each trip and guaranteed the leak will show it's origin after the first two trips Link to comment Share on other sites More sharing options...
hitman72 Posted September 5, 2013 Share Posted September 5, 2013 I put mine here ... upper left in the picture. Also replaced my MAP and Fuel pressure regulator Vacuum lines with Brake line (still the leaking plastic in the pictures), fit the end fittings much more securely and won't crack or melt in my lifetime. Have you tried cleanning the IAT (Inlet Air Temp sensor)? checked the ECU's coolant temp sensor (lower driver side of manifold)? MAP? And as mentioned the O2 sensor. How is you're EGR system functioning? Mine was fubar so it was deleted (which also happens to be the bulk of the vacuum harness). Last trip was a 21mpg avg over 500km's Yes, I still need to replumb the EVAP cannister as well So if you unhook the vacuum canister you do in fact have to "recharge" the system? How is this done? sorry for the thread jack. Link to comment Share on other sites More sharing options...
hitman72 Posted September 5, 2013 Share Posted September 5, 2013 Just my 2 cents, check your air cleaner. Bought my truck and did not check it before buying it (yes i know very stupid of me), drove it home and got horrible mileage. Scared me really bad haha. Opened up the air box to find out that the PO put to much oil in the engine. VC has a plow off rose that runs to the air box. My air filter looked like a sponge. Changed it, cleaned the throttle body, and C-foamed the engine, getting good mileage now. Link to comment Share on other sites More sharing options...
Comanchemodder Posted September 5, 2013 Share Posted September 5, 2013 The three vacuum harness lines are Dorman PN 46003, 46004 and 46005. Are these the same part numbers for the 2.5L 4Cyl vacuum harness? Thanks! Link to comment Share on other sites More sharing options...
Rockfrog Posted September 5, 2013 Share Posted September 5, 2013 So if you unhook the vacuum canister you do in fact have to "recharge" the system? How is this done? sorry for the thread jack. pop the hose off, trim accordingly for new location, rehook Vacuum hoses, start motor. Done. It's a vaccum canister with a check valve in the vaccum line, it simply stores a vaccum that the engine itself creates. Link to comment Share on other sites More sharing options...
88whitemanche Posted September 5, 2013 Share Posted September 5, 2013 Unfortunately comanchemodder Those part #s are only for the 4.0 They don't make the vacuum harness for the 2.5s Link to comment Share on other sites More sharing options...
Oyaji Posted September 6, 2013 Share Posted September 6, 2013 So if you unhook the vacuum canister you do in fact have to "recharge" the system? How is this done? sorry for the thread jack. pop the hose off, trim accordingly for new location, rehook Vacuum hoses, start motor. Done. It's a vaccum canister with a check valve in the vaccum line, it simply stores a vaccum that the engine itself creates. Good description of the system, but when you conclude that the evaporative emissions systems "stores a vacuum" you are off the mark. Since the purpose of the canister is to store gasoline vapors that evaporate off the fuel in the gas tank, it is connected to the tank, which is in turn vented to the atmosphere via a check valve (usually in the gas tank cap) that allows air in but doesn't allow vapors out. If there was vacuum in the fuel tank it would likely crush inwards (the canister might crush, too). Thus, the fuel tank and the cannister connected to it remain at atmospheric pressure, whether the engine is running or not. . The purpose of the check valve you mention is not to store vacuum, but rather for safety (by the way, it isn't really a "check valve" that operates only one way - it is an electrically-operated servo valve that opens upon receiving voltage from a running engine). It prevents the charcoal canister (yes, the canister contains fine charcoal - providing about 5 acres of surface area to bind and safely store gasoline vapor) from overflowing and passing explosive vapor to the manifold of a non-running engine, where otherwise on a hot day it might accumulate sufficiently to overflow from the manifold and air cleaner and into the engine compartment... whence upon engine startup, a stray spark might cause an underhood explosion. The other reason for the servo valve is to cut egress of leaking fuel in the event of a rollover accident. . Sorry for the highjack, but I was a homologation engineer. My only intention here is to provide clarity. . Now, to the point of the original post: Knucklehead97, on 01 Aug 2013 - 19:11, said: Okay guys I've recently been noticing that I've really got bad gas mileage. I had 160 miles on the trip when I added 15 gallons to it yesterday. I think I fixed the rough idle, need to get some vacuum line bushings though. I shift at 2300 rpms (to high? To low?) I'm running 30x9.50 mud tires on stock gears, could this result in anything?... Please give me every little thing that could be causing this because I can't afford the gas. Should I readjust the TPS? I don't think proper gearing is a "little thing". Since stock tires are around 27" diameter, running 30" tires adds something like a 10% increase in your overall gearing. That added diameter may be affecting your fuel economy significantly. Engines are designed with a "sweet spot" for best fuel efficiency. If you change your gearing, you are changing the speed at which that "sweet spot" delivers just the right amount of power to meet the power required to maintain that speed. The main factors that determine how much power you need are aerodynamic drag (if you lift your vehicle, this goes up) and tire rolling resistance (a more aggressive tread makes this go up too). It can get pretty complicated when you start changing things from stock... coast-down testing is really the only way to be sure (with the use of some math you can do this at home - but most folks consider it too complicated - Google it up if you are interested). Practically speaking, I think it would be best to just shoot for a little more RPM (~3%-ish) at your chosen cruising speed than stock (to account for things like lift and tire tread) and accept a small (maybe 1 mpg?) drop in economy. What you describe sounds like you have more issues than simply being wrongly geared, but that is for sure one place to start. If you have a spare set of rims with stock tires fitted, that would be a great comparison test to begin with. Link to comment Share on other sites More sharing options...
HOrnbrod Posted September 6, 2013 Share Posted September 6, 2013 That's all good to know, but this thread concerns the HVAC system vacuum reservoir, not the emissions system charcoal cannister. Good description of the system, but when you conclude that the evaporative emissions systems "stores a vacuum" you are off the mark. Since the purpose of the canister is to store gasoline vapors that evaporate off the fuel in the gas tank, it is connected to the tank, which is in turn vented to the atmosphere via a check valve (usually in the gas tank cap) that allows air in but doesn't allow vapors out. If there was vacuum in the fuel tank it would likely crush inwards (the canister might crush, too). Thus, the fuel tank and the cannister connected to it remain at atmospheric pressure, whether the engine is running or not..The purpose of the check valve you mention is not to store vacuum, but rather for safety (by the way, it isn't really a "check valve" that operates only one way - it is an electrically-operated servo valve that opens upon receiving voltage from a running engine). It prevents the charcoal canister (yes, the canister contains fine charcoal - providing about 5 acres of surface area to bind and safely store gasoline vapor) from overflowing and passing explosive vapor to the manifold of a non-running engine, where otherwise on a hot day it might accumulate sufficiently to overflow from the manifold and air cleaner and into the engine compartment... whence upon engine startup, a stray spark might cause an underhood explosion. The other reason for the servo valve is to cut egress of leaking fuel in the event of a rollover accident. Link to comment Share on other sites More sharing options...
Eagle Posted September 7, 2013 Share Posted September 7, 2013 So if you unhook the vacuum canister you do in fact have to "recharge" the system? How is this done? sorry for the thread jack. pop the hose off, trim accordingly for new location, rehook Vacuum hoses, start motor. Done. It's a vaccum canister with a check valve in the vaccum line, it simply stores a vaccum that the engine itself creates. Good description of the system, but when you conclude that the evaporative emissions systems "stores a vacuum" you are off the mark. Since the purpose of the canister is to store gasoline vapors that evaporate off the fuel in the gas tank, it is connected to the tank, which is in turn vented to the atmosphere via a check valve (usually in the gas tank cap) that allows air in but doesn't allow vapors out. If there was vacuum in the fuel tank it would likely crush inwards (the canister might crush, too). Thus, the fuel tank and the cannister connected to it remain at atmospheric pressure, whether the engine is running or not. . The purpose of the check valve you mention is not to store vacuum, but rather for safety (by the way, it isn't really a "check valve" that operates only one way - it is an electrically-operated servo valve that opens upon receiving voltage from a running engine). It prevents the charcoal canister (yes, the canister contains fine charcoal - providing about 5 acres of surface area to bind and safely store gasoline vapor) from overflowing and passing explosive vapor to the manifold of a non-running engine, where otherwise on a hot day it might accumulate sufficiently to overflow from the manifold and air cleaner and into the engine compartment... whence upon engine startup, a stray spark might cause an underhood explosion. The other reason for the servo valve is to cut egress of leaking fuel in the event of a rollover accident. . Sorry for the highjack, but I was a homologation engineer. My only intention here is to provide clarity. Good intentions, but all you accomplished was to introduce confusion. The vacuum canister being discussed here is the vacuum reservoir located behind the front bumper, NOT the charcoal fumes canister back by the firewall. The canister in question DOES store vacuum -- that is its only purpose. Without it -- or if it leaks or the lines to it leak -- any time you go up a steep-ish hill the drop in engine vacuum closes the ventilator doors and shifts all heat or a/c output to the defrost outlets on the top of the dashboard. Link to comment Share on other sites More sharing options...
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