Nefarious Posted March 2, 2012 Share Posted March 2, 2012 If your truck doesn't have the BPT valve and removing the EGR doesn't cause a CEL light then your good already. This idea is only for the guys having CEL problems after removing the EGR. The FSM should have impedance values for a good sensor, just use a large resistor like a 2 or 3 watt. James i know i was just saying for other people it would be a good idea i have the 'PROPER' version of the pathy that doesn't give unnecessary check engine lights. lol Link to comment Share on other sites More sharing options...
Mr.510 Posted March 2, 2012 Share Posted March 2, 2012 i have the 'PROPER' version of the pathy Yours isn't the 'proper' version, it's got too many doors! From the 1994 FSM: Somebody is going to have to play with some resistors or a potentiometer to see how the resistance effects the ECU wanting to throw codes. Since it's not a simple on/off temp switch and there's no data in the FSM for a range of temperatures it may or may not work to install a simple resistor in it's place. Link to comment Share on other sites More sharing options...
Tungsten Posted March 2, 2012 Share Posted March 2, 2012 An alternative option could be to stick the temperature probe into the EGR bung in the exhaust manifold with some special adapter. It would work just as well I imagine. Link to comment Share on other sites More sharing options...
tmoore4512 Posted March 2, 2012 Author Share Posted March 2, 2012 The resistor is a good option but I agree with 510, you would have to play around with it... I am sure the ECU has a range of GOOD temp readings and anything outside of that will throw the code... Tungsten's idea is also spot on... If the exhaust temperature was within the same range as the intake near the EGR, then it should work... however being that there is a 12 inch or more span of un insulated tube coming from the manifold to the EGR valve, it is quite possible that the temp difference is going to be massive... Time to break out the IR thermometer!!! Link to comment Share on other sites More sharing options...
amfq120 Posted March 3, 2012 Share Posted March 3, 2012 (edited) Mine's a 94 and I had a BPT valve and removed it when I bought a new EGR valve. No check engine light or codes. Edited March 3, 2012 by amfq120 Link to comment Share on other sites More sharing options...
Tungsten Posted March 3, 2012 Share Posted March 3, 2012 Did you remove the BPT valve or the EGR valve? Only removing the BPT valve will not do anything but increase the amount of exhaust gas re-circulation. Link to comment Share on other sites More sharing options...
ejin4499 Posted March 5, 2012 Share Posted March 5, 2012 If you switch your ecu to a federal 90-93 and switch your o2 sensor to the old smaller style I think you can side step the whole issue. Also for anyone in Cali the federal will still pass smog but give you a little bit better fuel map. I swapped mine out and could tell the difference, not a huge difference mind you but a difference. Link to comment Share on other sites More sharing options...
silverton Posted March 5, 2012 Share Posted March 5, 2012 I have EGT sensor code, with EGR blocked off completely, and so far am getting better gas milage. I'll know true readings at my next fill up, but trip meter -> fuel needle location readings are much better! Link to comment Share on other sites More sharing options...
Nefarious Posted March 5, 2012 Share Posted March 5, 2012 Yours isn't the 'proper' version, it's got too many doors! Touche! Lol Link to comment Share on other sites More sharing options...
Nefarious Posted March 5, 2012 Share Posted March 5, 2012 Yeah my mileage and power both increased once I removed the egr... Link to comment Share on other sites More sharing options...
tmoore4512 Posted March 6, 2012 Author Share Posted March 6, 2012 All of this has me thinking...how much better it will run with a GM 4.3 in it!!! Link to comment Share on other sites More sharing options...
ejin4499 Posted March 6, 2012 Share Posted March 6, 2012 All of this has me thinking...how much better it will run with a GM 4.3 in it!!! well sure if you want to take the easy way out. Link to comment Share on other sites More sharing options...
JamesRich Posted March 6, 2012 Share Posted March 6, 2012 All of this has me thinking...how much better it will run with a GM 4.3 in it!!! Just remember that 4.3 won't last as long as a well built VG motor! James Link to comment Share on other sites More sharing options...
tmoore4512 Posted March 7, 2012 Author Share Posted March 7, 2012 Going 4.3 simply because its 100 times cheaper to build, will create more power, and the parts are way easier to source than the VG30... No argument about the strength of a VG30 built or not... I am a believer, but for my budget it is cheaper to do a complete drive line swap then to rebuild the tired VG30. I would hate to spend the money on building the VG, then have the transmission go belly up... Link to comment Share on other sites More sharing options...
ejin4499 Posted March 7, 2012 Share Posted March 7, 2012 Going 4.3 simply because its 100 times cheaper to build, will create more power, and the parts are way easier to source than the VG30... No argument about the strength of a VG30 built or not... I am a believer, but for my budget it is cheaper to do a complete drive line swap then to rebuild the tired VG30. I would hate to spend the money on building the VG, then have the transmission go belly up... why rebuild a vg30 when you can drop in a vg33 out of a 2003 xterra? While your at it drop in the transmission out of the same xterra along with a cooler bypass and your set. Link to comment Share on other sites More sharing options...
tmoore4512 Posted March 7, 2012 Author Share Posted March 7, 2012 Same issue... cannot find a useable X or F motor....majority are destroyed.... in my AO Link to comment Share on other sites More sharing options...
krmiller07 Posted March 7, 2012 Share Posted March 7, 2012 (edited) This may be a bit off topic, but I am wondering what a 'BPT' valve is. I have an 89 VG30 and don't recall seeing or reading about a BPT valve in any manuals or FSM. I do know there is an 'AB' or anti-backfire valve / vacuum solenoid that has a small rubber hose running up to the air cleaner canister. I also notice that when it's warming up and just before it comes off of high idle during warm up, it has a tendency to 'pop' or back fire just a little bit, before idling at a normal rpm. How important is the 'AB' valve and what would happen if it was removed/ bypassed or eliminated? As for removing the EGR, in an effort to increase power and fuel mileage. Has anyone experienced any 'real time' benefits to this? Or is it all seat off the pants and visual fuel gauge readings that you are going off of? Thanks Edited March 7, 2012 by krmiller07 Link to comment Share on other sites More sharing options...
Nefarious Posted March 7, 2012 Share Posted March 7, 2012 (edited) my power and mileage definitely increased. unmistakable difference in throttle response and a bit of power, the engine runs more smoothly and my mileage went up 1mpg on average. i average 20mpg on the highway with vg33e with NO egr, NO catalytic converter in a wd21 with 6 inches of lift on 33x12.5 tires. i am running larger than stock tires but because it drops my highway revs down below 2k rpm my mileage stayed the same or improved. not much city driving here mostly highway and trails so i can only give you those figures. my alignment needs to be done and im running 50+ lbs each steel rims (15x10). im sure once i get an alignment and switch to these new 17-18 lb 15x8 alloys my mileage will improve significantly more. Edited March 7, 2012 by Nefarious Link to comment Share on other sites More sharing options...
Tungsten Posted March 7, 2012 Share Posted March 7, 2012 This may be a bit off topic, but I am wondering what a 'BPT' valve is. I have an 89 VG30 and don't recall seeing or reading about a BPT valve in any manuals or FSM. I do know there is an 'AB' or anti-backfire valve / vacuum solenoid that has a small rubber hose running up to the air cleaner canister. I also notice that when it's warming up and just before it comes off of high idle during warm up, it has a tendency to 'pop' or back fire just a little bit, before idling at a normal rpm. How important is the 'AB' valve and what would happen if it was removed/ bypassed or eliminated? As for removing the EGR, in an effort to increase power and fuel mileage. Has anyone experienced any 'real time' benefits to this? Or is it all seat off the pants and visual fuel gauge readings that you are going off of? Thanks A BPT valve is a supplementary valve that runs off the EGR valve controlling its vacuum. The system goes something like this: From the exhaust side: Exhaust Manifold -> Tube -> EGR -> BPT From the intake side: Intake Manifold -> Hose -> EGR and BPT The BPT valve reduces the vacuum from the intake to the EGR valve by creating a slight vacuum leak to the EGR valve. What this does is reduce how much the EGR valve opens and how much exhaust gas is recirculated. The BPT is an old school way to control the EGR valve. Nissan removed the need for a BPT valve by adding a cut off solenoid but then later on what they did was put the BPT back in for more performance. Remember that the EGR is meant to do one thing: Reduce NOx emissions. One of the jobs of the catalytic converter is to also reduce NOx emissions. If you have a good enough catalytic converter then you might as well toss that EGR valve into the garbage can and still be able to pass smog. I haven't tested this yet but I almost guarantee you that if you use a 2.5" Magnaflow converter you will not need an EGR valve for that extra NOx reduction. Link to comment Share on other sites More sharing options...
krmiller07 Posted March 7, 2012 Share Posted March 7, 2012 Thanks. I haven't had a catalytic converter on this truck since shortly after buying it. The exhaust system was rotted and I had the guy just cut off the system from just before the mounting flange. I'm currently running a 'stockish' sized exhaust pipe from the old cat mounting point all the was back to the end, with a OEMreplacementt sized muffler. I think the OD size of the exhaust, tail pipe and muffler in put and out put sizes are 2 1/4 "'s. I am still using the EGR along with the 'pre-heater' under the throttle body to assist in warm up. (I live in Minnesota) so during the winter, it tends to cool off a bit! I have heard of some people eliminating the TBI heater all together due to there tendency to fall apart and get sucked through the intake system! Quite frankly, my fuel mileage really sucks (no pun intended) and I don't run an aggressive tread pattern on the tires(all season/ all terrainalthoughugh the engine runs extremely smooth with great throttle response and idle and normal warm up characteristics. I would really like better fuel mileage, and if I happen to pick up a few HP, thats fine too! I have an SE, so the tire siremainsins stock at 31-10.50-15, with a mild lift in the way of JGC rear springs and cranked up front torsion bars. I noticed I also have what looks like an 'idle mixture' screw on the back drivers side of the TBI. I have read a post on here that sometimes can effect the mileage, but I haven't seemed to find the happy medium in which to adjust and set it properly. Some have said turning tsewcew 'in' will richen the mixture, while others have said, it will do just the opposite and richen the mixture? Has anyone confirmed this? Link to comment Share on other sites More sharing options...
Tungsten Posted March 7, 2012 Share Posted March 7, 2012 Sometimes the EGR valves can stick and cause poor performance and fuel mileage issues. If you don't run a cat and that's fine for where you live then you can definitely disconnect the EGR and take it to your nearest garbage disposal. Have you done a tune up by any chance? Link to comment Share on other sites More sharing options...
krmiller07 Posted March 7, 2012 Share Posted March 7, 2012 Yes. I do tune ups on a regular and almost religious basis. We don't have emissions testing in MN so that's not a concern. The last tune up was performed this fall. Checked and replaced all the normal stuff. Plugs, wires, dist. cap, rotor, fuel filter. Run Sea Foam through the system just to keep or help clean the injectors (2) from gumming up. I set the timing 2 degrees advanced, just in an effort to help with mileage on the highway. Recently replaced the Head temp sensor behind the distributor and have replaced nearly all the vacuum lines (where they would matter) Mechanics whom I have gone to for advise and help, have commented on how well it runs! But I still avg about 8-10 mpg in town and maybe 10-12 mpg on the highway. Compression andleak downn tests are all within spec. I even over inflate the tires in an effort to reduce rolling resistance! I had one of these trucks new, when they first came out, and I remember they were never know for stellar fuel mileage, but I don'trememberr them being this bad! I'm about out of ideas! Link to comment Share on other sites More sharing options...
tmoore4512 Posted March 7, 2012 Author Share Posted March 7, 2012 This may be a bit off topic, but I am wondering what a 'BPT' valve is. I have an 89 VG30 and don't recall seeing or reading about a BPT valve in any manuals or FSM. I do know there is an 'AB' or anti-backfire valve / vacuum solenoid that has a small rubber hose running up to the air cleaner canister. I also notice that when it's warming up and just before it comes off of high idle during warm up, it has a tendency to 'pop' or back fire just a little bit, before idling at a normal rpm. How important is the 'AB' valve and what would happen if it was removed/ bypassed or eliminated? As for removing the EGR, in an effort to increase power and fuel mileage. Has anyone experienced any 'real time' benefits to this? Or is it all seat off the pants and visual fuel gauge readings that you are going off of? Thanks Not off topic at all bro. I am the one who threw a wrench into the mix and started talking about defecting from the VG to the GM side of motors and such... Have you checked your codes? It is possible that a sensor is out of wack or something... Because even with my leaky and tired VG30 I still average 12-14 in the city!! Link to comment Share on other sites More sharing options...
fixinto Posted December 27, 2012 Share Posted December 27, 2012 Yes. I do tune ups on a regular and almost religious basis. We don't have emissions testing in MN so that's not a concern. The last tune up was performed this fall. Checked and replaced all the normal stuff. Plugs, wires, dist. cap, rotor, fuel filter. Run Sea Foam through the system just to keep or help clean the injectors (2) from gumming up. I set the timing 2 degrees advanced, just in an effort to help with mileage on the highway. Recently replaced the Head temp sensor behind the distributor and have replaced nearly all the vacuum lines (where they would matter) Mechanics whom I have gone to for advise and help, have commented on how well it runs! But I still avg about 8-10 mpg in town and maybe 10-12 mpg on the highway.Compression andleak downn tests are all within spec. I even over inflate the tires in an effort to reduce rolling resistance! I had one of these trucks new, when they first came out, and I remember they were never know for stellar fuel mileage, but I don'trememberr them being this bad! I'm about out of ideas! Try checking your long term fuel trim and c where its at, if you have a vacuum leak or a funky sensor it will spray the crap out of fuel to try to compensate for the "lean" mix. I rock a decent 20ish MPG hwy and im happy with that for an suv. its a 96 SE VG33e. bone stock as far as i know and still has all the emissions do dads on it. even the EVAP. So ya when u said 10 - 12 i think i threw up a little in my mouth. Link to comment Share on other sites More sharing options...
peejay Posted January 22, 2014 Share Posted January 22, 2014 Okay, so you guys sound like EGR pros, hopefully you can help me out! I've got a 94 Pathfinder, it has the EGR valve, but not the BPT valve...my CEL is on, and giving me a code 32 (EGR function) and 34 (knock sensor)... My question, what is port "C" for??? And when I perform tests on the EGRC solenoid, i can NEVER get a vacuum gauge to register any vacuum at port "A" (the connetion to the intake boot)...since that port is so far away from the manifold, will it ever register vacuum? The only way I can get my EGR valve to operate is if i connect "A" to the throttle body (a "better" source of vacuum?)...However, my CEL is still on, but I haven't taken the EGR valve itself off and inspected/cleaned it... And you guys who have ditched your EGR systems aren't worried about detonation, knock, or preignition from combustion temps getting too high? Is that a bunch of baloney? The previous engine in this truck detonated BADLY, the ceramic was broken off all the plugs, engine had no power...I'm thinking the EGR system went out, and the previous owner never got it fixed, which caused the detonation? Not sure, but I don't wanna mess up the "new" engine the same way.. Plus, I live in Atlanta, and the sniffer test is a must, unfortunately. Thanks for any help! Link to comment Share on other sites More sharing options...
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