89_trailboss Posted May 31, 2006 Share Posted May 31, 2006 (edited) alright, VG30I. put a new intake on. only hose that I didnt hook up was for the air intake temp sensor. I simply put a screw into the end of the hose. truck idles fine, with no load(not in gear) it will rev fine. it will drive fine, except for when I reach 1/2 throttle. the motor starts to drown itself out. and im sure if I kept given on the skinny it would probly stall out. almost like theres too much fuel. anyideas what could be wrong? If I put the old air box/intake back on it will run fine. this "new" intake Is somthing that I made. it sits ontop of the TBI(steel airbox idea) then goes into a flex/rubber pipe(off of a VG30E) then into 2" ABS into the fender then up by the Apillar it goes into a 3" ABS pipe then there is a cone filter on the roof. the only thing that isnt like stock is the fact that temp sensor hose isnt hooked up(screw in it) and there is a hiflow cone filter instead of the new fram. HELP :help: <- Edited your title for ease of search locating it later - V -> Edited June 7, 2006 by vengeful Link to comment Share on other sites More sharing options...
89_trailboss Posted May 31, 2006 Author Share Posted May 31, 2006 actually, after reading my post again. its kinda stupid. obviously the problem is the fact that the temp sensor isnt hooked up. is there anyway I can cheat/bypass this? maybe 88 could chimn in??? Link to comment Share on other sites More sharing options...
Precise1 Posted May 31, 2006 Share Posted May 31, 2006 LOL at answering your own question... Definitely post a pict of the E series snorkel !! Is there a reason you can't drill/tap the ABS or the steel box for the sensor ?? Not exactly sure where it normally mounts, but you get the idea. Cheap and easy while keeping the computer happy... B Link to comment Share on other sites More sharing options...
88pathoffroad Posted May 31, 2006 Share Posted May 31, 2006 There is no intake air temp sensor on a VG30i. There's just the air cleaner hot air riser valve and actuator for cold start-up. Hmmmm, wierd. There's nothing else obstructing the piping anywhere internally? Pics might help. Link to comment Share on other sites More sharing options...
mws Posted May 31, 2006 Share Posted May 31, 2006 How big is the plenum on top of the TBI? You could be getting some kind of a pressure pulse resonance in the system. Try disconnecting the piping right at the plenum. If the problem goes away, then it may be as simple as changing the sizes/volumes of different pipes to move the harmonic frequency to somewhere it doesn't hinder performance. And I would also like to see pictures if possible. Link to comment Share on other sites More sharing options...
89_trailboss Posted May 31, 2006 Author Share Posted May 31, 2006 the plemn actually is quite small. I tried disconnecting the pipe right at the plemn, same thing happens. But, what does this A.B. valve do? In the rush of things I grabed heater hose and slaped it inbetween the intake man. and the AB valve(basically lengthen the stock peice). but that hose is under vacum and as soon as I start the truck that hose calapses like no other. like there is NO air getting threw. so im gussing thats the problem, no? and the EGR, any better milage/performance? teacher said that I would probly see some gains if I unhook it. I does work(moves and holds itself when finger is over hose) and I will try and get pics Link to comment Share on other sites More sharing options...
89_trailboss Posted June 1, 2006 Author Share Posted June 1, 2006 alright, AB valve= anti backfire valve. do I really need this? Link to comment Share on other sites More sharing options...
88pathoffroad Posted June 1, 2006 Share Posted June 1, 2006 I was thinking about this today, and I think mws may have hit the nail on the head...the stock airbox has a fairly large capacity for holding air. If you swap that out with a small, tight-fitting box it's going to suck most of the available air out of the intake tube right away and then not have enough to run right after you hit 1/2 throttle. Just a thought, I may be wrong entirely. You can remove the AB valve if you want, I did and haven't had any problems with it. Just make sure you plug the old fittings off well. Link to comment Share on other sites More sharing options...
89_trailboss Posted June 1, 2006 Author Share Posted June 1, 2006 MWS hit it on the head!!! I threw the old box on and it drove fine. then started the process of elimination. had NOTHING hooked up and still ran fine. so the only thing left is the fact that the air box is too small. so I will be throwing one together later this week and tryin it again. the box I made only let air in for the front of the TBI to breath in. there was about 1/2" from the sides and back of the TB to the walls of the box. here was the basic idea, stock after: (notice the racing red cap!!!! haha) Link to comment Share on other sites More sharing options...
Precise1 Posted June 1, 2006 Share Posted June 1, 2006 COOL !! I'm glad the enginerd nailed it !! Please post about your future changes as several people will be very interested... Snorkels for the TBI units have been 'impossible' until now. I almost bought an 89 and was palnning to prove people wrong but it didn't work out. Martin (the enginerd) got it instead... Too bad, I was looking forward to creating a package, but I didn't need another Pathy with front end problems... B Link to comment Share on other sites More sharing options...
89_trailboss Posted June 1, 2006 Author Share Posted June 1, 2006 made another box. will have to see what happens. I dont think I will have time to put it on till this weekend tho. Link to comment Share on other sites More sharing options...
madhatter_xe Posted June 1, 2006 Share Posted June 1, 2006 (edited) That is friggin sweet dude. Hopefully the bigger box solves the problem. Nice work! Edited June 1, 2006 by madhatter_xe Link to comment Share on other sites More sharing options...
89_trailboss Posted June 1, 2006 Author Share Posted June 1, 2006 That is friggin sweet dude. Hopefully the bigger box solves the problem. Nice work! wait till you see a big ricey cone filter on the roof, haha thanks for the words guys Link to comment Share on other sites More sharing options...
vengeful Posted June 1, 2006 Share Posted June 1, 2006 wait till you see a big ricey cone filter on the roof, haha thanks for the words guys 89_Trailboss....taking cold air intake to an entirely new extreme!! Link to comment Share on other sites More sharing options...
89_trailboss Posted June 3, 2006 Author Share Posted June 3, 2006 bigger box solved the problems :o drives great. removed the A.B. valve and removed the vacum hose for the EGR. seems to be a bit of boost in power too!!!. the box is just a cut up stock box. unfortunantly it is round( the look I didnt want) so I will probly make a new on when I have time to change the looks of it. but it works!!!. and it had nothing to do with any hoses.you can run these things fine without any of that crap. the only hose that is hooked up is the crank case vent. other wise theres just a SH!T load of bolts plugin everything, haha. ill try and grab some pix once I throw some paint on it. Link to comment Share on other sites More sharing options...
madhatter_xe Posted June 6, 2006 Share Posted June 6, 2006 schweeet! *checks price of snorkel*... ...not so schweet. Link to comment Share on other sites More sharing options...
89_trailboss Posted June 7, 2006 Author Share Posted June 7, 2006 schweeet! *checks price of snorkel*... ...not so schweet. abs pipe is your friend. In total this mod cost me MAYBE 50 bucks, with the cone filter. filter- $30 bucks fittings- $15 2 90* 4 45* 1 22.5* 1 3" 45* 1 2-3" adaptor then the stock VG30E peice was a freebe from the JY and pipe I had laying around. think It was somthing like 40"x2" ABS and 22" of 3" Pics are coming, hopfully tommorow Link to comment Share on other sites More sharing options...
dagwoodzz Posted June 7, 2006 Share Posted June 7, 2006 Can you edit the title of your post? I'm going to want to find this again but the search function might have trouble finding it. BTW, looks like your on to something good! Link to comment Share on other sites More sharing options...
vengeful Posted June 7, 2006 Share Posted June 7, 2006 Done Link to comment Share on other sites More sharing options...
madhatter_xe Posted June 7, 2006 Share Posted June 7, 2006 abs pipe is your friend. yeah for that price ABS is the way to go. Looking forward to some pics. Link to comment Share on other sites More sharing options...
87pathy Posted June 7, 2006 Share Posted June 7, 2006 there is a hiflow cone filter instead of the new fram. HELP :help: <- Edited your title for ease of search locating it later - V -> this could possibly be the problem. I remember when i took my air filter out (essentially allowing more flow due to no filter restiction) I had the same effects you are mensioning, like its dronding out. and if you floor it acts like its gonna die. try some restriction in the line, just to eliminate the possibility. Link to comment Share on other sites More sharing options...
madhatter_xe Posted June 7, 2006 Share Posted June 7, 2006 bigger box solved the problems drives great. removed the A.B. valve and removed the vacum hose for the EGR. seems to be a bit of boost in power too!!!. Link to comment Share on other sites More sharing options...
mws Posted June 8, 2006 Share Posted June 8, 2006 Now that I've seen your plenum, I suspect the real root cause was aerodynamic turbulence. As the RPM increased, the air volume and velocity increased. It would come rushing into the smallish plenum and swirl around in there, hitting the cones of fuel coming out of the injectors from the side and disrupting proper dispersion. Increasing the size will definitely help. The new box may require some trial and error to avoid turbulence and the aforementioned pressure resonance issues. Engineers actually spend many, many hours designing intake tracts to eliminate them from new designs. You may have to add air diverting features to avoid the turbulence. I would suggest having the air come in well to the side of the TB, and as low as possible. And then make the plenum as tall as possible so you can add an extension above the TB (like a velocity stack) that extends up at least 3 or 4 inches above where the air comes in. And then a couple fins inside to reduce swirling or cyclone actions within the plenum itself. So the air comes into the plenum and hits a few diffusers and then works it's way upwards and is drawm into the velocity stack where it is guided nice and smoothly into the TB throat. I want to do what you're doing on both my van (for cfm reasons) and on the Pathy (for water ingestion reasons). Your experience makes me even more likely to use the stock air filter enclosure for the plenum! Ugly, yes, but the engineering to assure smooth flow is already done! Link to comment Share on other sites More sharing options...
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