Hybrid_From_Hell Posted May 21, 2013 Share Posted May 21, 2013 think with your hand over the plenum where / how would air get into your engine to let it run ???? If it runs with hand over entry - you have an air entry leak chap This is NOT a MS Issue, its a phyiscal engine issue problem Nige Quote Link to comment Share on other sites More sharing options...
mikec Posted May 21, 2013 Author Share Posted May 21, 2013 I seem to remember somebody saying that one of the bolt holes for the throttle body heater plate actually goes all the way through in to the air intake, so if you don't have the heater plate on (or bolts in the holes) you will have an air leak there.I notice you have no heater plate? Fridge said it in http://forums.lr4x4.com/index.php?showtopic=81771&page=3&hl=+plenum++heater#entry703018 Yep I read that in SAMs thread, he had two holes that went into the intake, mine must of been a Friday afternoon plenum because it had 3 of the 4 holes that went in to it Quote Link to comment Share on other sites More sharing options...
mikec Posted May 21, 2013 Author Share Posted May 21, 2013 thinkwith your hand over the plenum where is the air going to get into your engine ? If it runs you have an air entry leak chap Nige But in the third pic, the pipe that runs from the rocker to the intake, that pipe just supplys it with enough to idle on on mine? When I crushed that yesterday I'm sure it stopped the engine. Quote Link to comment Share on other sites More sharing options...
mikec Posted May 21, 2013 Author Share Posted May 21, 2013 Should add to help try to find any leak I've given it a spray with brake cleaner too, obviously carefully, as much as I hate it at the minute I could do without setting it on fire Quote Link to comment Share on other sites More sharing options...
mikec Posted May 21, 2013 Author Share Posted May 21, 2013 What other causes could it be? Timing would be on my list, might have a play with that tomos on megatune, how much would it need to be out for it to be like this? It'd only be a couple of degrees out at most. Other than that what else. I just cant see how it can be air, when I fitted the new inlet I sealed EVERYTHING with rtv even the inlet manifold. Quote Link to comment Share on other sites More sharing options...
Mr Noisy Posted May 21, 2013 Share Posted May 21, 2013 Mike I'm afraid I haven't tried to stop mine with hand over intake but I can do this if it would help you. On most accounts though it should stop when blocked even if it could run on some air through the breather. Tbh I think it would not be able to get enough air through breather. I really think you need a fresh set of eyes to look at this pal cos you might be just too fried! Quote Link to comment Share on other sites More sharing options...
Mr Noisy Posted May 21, 2013 Share Posted May 21, 2013 Like nice said, if it runs with hand over the inlet, you have a bad leak, simple. Don't try to think about timing or anything. Hand over intake and listen for the sucking sound! Quote Link to comment Share on other sites More sharing options...
zardos Posted May 21, 2013 Share Posted May 21, 2013 I don't know if you could make an adapter to pressure test the plenum by putting low level compressed air in to it? You could measure pressure drop on a gauge and or spray soapy water and look for bubbles? Might be easier than trying to find where it is sucking it in? Quote Link to comment Share on other sites More sharing options...
mikec Posted May 21, 2013 Author Share Posted May 21, 2013 Mike I'm afraid I haven't tried to stop mine with hand over intake but I can do this if it would help you.On most accounts though it should stop when blocked even if it could run on some air through the breather. Tbh I think it would not be able to get enough air through breather. I really think you need a fresh set of eyes to look at this pal cos you might be just too fried! I'm not being argumentative here, so hopefully no one takes this the wrong way but I just want to be sure about this. When its idling the butterfly's normally shut? So all the air needed to idle is supplied by the the little pipe on the right hand side just inside the throttle body? That's only the same size as the breather pipe. Now although that pipe on the rhs inside the tb looks like it goes straight to the pwm pipe, it doesn't, it must split inside the plenum somewhere. Quote Link to comment Share on other sites More sharing options...
mikec Posted May 21, 2013 Author Share Posted May 21, 2013 I don't know if you could make an adapter to pressure test the plenum by putting low level compressed air in to it?You could measure pressure drop on a gauge and or spray soapy water and look for bubbles? Might be easier than trying to find where it is sucking it in? Yep could be easier, least I'd not have the engine noise to contend with then. I'd just have to figure a way of boding an adapter. Quote Link to comment Share on other sites More sharing options...
Mr Noisy Posted May 21, 2013 Share Posted May 21, 2013 I'm not being argumentative here, so hopefully no one takes this the wrong way but I just want to be sure about this. When its idling the butterfly's normally shut? So all the air needed to idle is supplied by the the little pipe on the right hand side just inside the throttle body? That's only the same size as the breather pipe. Now although that pipe on the rhs inside the tb looks like it goes straight to the pwm pipe, it doesn't, it must split inside the plenum somewhere. Yeah you're right there I guess, so in theory it could run on the breather pipe diameter. You are right to assume that when a car has a idle valve the throttle flap is fully closed at idle. The airflow splits inside the plenum for the idle control because you have the pipe the the idle valve but you also have the base idle screw, this is where it splits off. I wonder say perhaps if your base idle screw/porting is faulty? Quote Link to comment Share on other sites More sharing options...
mikec Posted May 21, 2013 Author Share Posted May 21, 2013 Not sure wether to swap over another plenum top or not. Is there anything realistically that could achieve? Why's it revving away with the pipe between the two pwm pipes? Is that normal? Quote Link to comment Share on other sites More sharing options...
Mr Noisy Posted May 21, 2013 Share Posted May 21, 2013 Would be easy enough to pressurise the plenum assembly, just remove the MAT sensor if you need a handy hole. When we are pressure testing at work we use a tyre valve fitted into the tyre pressure gun, the soft rubber and rounded shape makes it easy to squish into most holes etc and get a good seal. Failing that, get a thread adaptor of correct description and thread into hole then fit PCL male and connect to airline hose. All you have to do is block your air filter inlet or snorkel top etc. Did you know, handy trick, get engine running and get mate to block plenum inlet (maybe use wood etc cos this could take a while) Get a good seal and make sure the leak is working to its full potential, then grab a short piece of hosepipe and put one end in your ear then work around the engine with the other end. You will VERY CLEARLY hear the air rushing in when you put the end of the hose near the leak! Quote Link to comment Share on other sites More sharing options...
Mr Noisy Posted May 21, 2013 Share Posted May 21, 2013 Not sure wether to swap over another plenum top or not. Is there anything realistically that could achieve?Why's it revving away with the pipe between the two pwm pipes? Is that normal? If you have a faulty plenum top it would explain why you have not been able to find a leak so far yes. If you connect the original pipe between the two idle valve ports and you do NOT have a stepper valve fitted then it will rev very high indeed, because you have a straight pipe from one side of the throttle flap to the other. I would be fitting a pwm valve personally, when I fired mine up and didn't know about the throttle heater problem I couldn't get I below 1500rpm no matter what I did, but me personally would fit your pwm valve so that you're running your exact correct setup and MSQ settings before trying to fiddle anything to get it right. Quote Link to comment Share on other sites More sharing options...
Mr Noisy Posted May 21, 2013 Share Posted May 21, 2013 Without looking at this and having the chance to be baffled myself I've gotta say im sorry but I'm sure you must be missing something here and probably quite simple. The hosepipe technique is very good for finding air leaks. Quote Link to comment Share on other sites More sharing options...
zardos Posted May 21, 2013 Share Posted May 21, 2013 My additional thoughts on pressure testing. Cut a finger end off a Marigold rubber glove and push tyre pressure gauge end in to end of finger through the hole.Jubilee clamp the finger to pipe using silicon sealant to get good seal. Place the hand end over plenum inlet and Jubilee clamp tight (with optional silicon) Inflate Marigold glove so you can see it start to stretch If the glove deflates you have a leak, you can also then use soapy water spray to find leak Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted May 21, 2013 Share Posted May 21, 2013 Phanarr sounds fun ...May be gone for a while ....... Quote Link to comment Share on other sites More sharing options...
Mr Noisy Posted May 21, 2013 Share Posted May 21, 2013 Aye, that glove idea is a handy one Quote Link to comment Share on other sites More sharing options...
Mr Noisy Posted May 21, 2013 Share Posted May 21, 2013 (LOL) Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted May 22, 2013 Share Posted May 22, 2013 If, as mikec has said, it stalls when he clamps the breather pipe, then surely this is where the problem lies? Quote Link to comment Share on other sites More sharing options...
mikec Posted May 22, 2013 Author Share Posted May 22, 2013 Would be easy enough to pressurise the plenum assembly, just remove the MAT sensor if you need a handy hole.When we are pressure testing at work we use a tyre valve fitted into the tyre pressure gun, the soft rubber and rounded shape makes it easy to squish into most holes etc and get a good seal. Failing that, get a thread adaptor of correct description and thread into hole then fit PCL male and connect to airline hose. All you have to do is block your air filter inlet or snorkel top etc. Did you know, handy trick, get engine running and get mate to block plenum inlet (maybe use wood etc cos this could take a while) Get a good seal and make sure the leak is working to its full potential, then grab a short piece of hosepipe and put one end in your ear then work around the engine with the other end. You will VERY CLEARLY hear the air rushing in when you put the end of the hose near the leak! Ill try that mate cheers. Quote Link to comment Share on other sites More sharing options...
mikec Posted May 22, 2013 Author Share Posted May 22, 2013 If, as mikec has said, it stalls when he clamps the breather pipe, then surely this is where the problem lies? Don't know mate, I could do with another car so I could compare them! Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted May 22, 2013 Share Posted May 22, 2013 It must be. You have an air leak somewhere - as shown by the fact it doesn't stall when you put your hand over the plenum. If, as you have said previously in this thread that it stalls when you put your hand over the plenum with the breather pipe clamped, then your leak must be the breather pipe. Block it off/clamp it/jam a bolt in it with jubilee clip, let the crankcase breath to atmosphere, and stick your hand over the intake again. If it stalls, go for a drive. Personally, I'm not convinced it is an air leak causing your problems - but this is not my area of expertise. Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted May 22, 2013 Share Posted May 22, 2013 Saw this : This is a hole directly into the trumpet area. Just what are these biungs you have on this and the PWM exit re of plenum and port onto plenum ? They need to be airtight not "Near enough" air will find a way in A hose + Bolt up the hole + 2 x jubilee clips is a far better solution. If there is ANY doubt that you may have an air leak, any possiblities have to be double sure that they are OK. Check all pipes for splits cracks etc, only way is to remove and study carefully, inc the tubes on the rear of the plenum Also Place engine at TDC on the crank wheel indicator, then take a picture of the trigger wheel and VR sensor positioning and post up N Quote Link to comment Share on other sites More sharing options...
Mr Noisy Posted May 22, 2013 Share Posted May 22, 2013 Do the hosepipe test on everything Can't believe this hasn't been found yet, IF it is a mechanical issue Quote Link to comment Share on other sites More sharing options...
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