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Joogie
Fully Licenced
291 Posts
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 Posted - 18 Jun 2006 : 8:39:25 PM
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Okay i have a 91 VN thats always gone really good until some days recently for unknown reasons it seems to be really down on power. It was awesome yesterday and then today it seemed really sluggish. I have never replaced the 02 sensor as i have only had it a few months and i was wondering if that could have something to do with it? It didnt have any power except if i really reved it hard and felt slower than my mums sonata.... I have not done any mods to it but have a CAI ready to go but before i fit it i want to sort out this mystery because its giving me the S@#ts! If you could help i would be gratefull! cheers guys
PS its an auto....
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mouce
National Driver
1525 Posts
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Posted - 18 Jun 2006 : 9:20:48 PM
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If it feels like it takes a bit to get going, but really moves well once the revs get a bit higher, then I'd start looking at your coil pack/leads/plugs. If any one of those is on the way out, it feels like a real pig below about 2000 rpm. After 2500rpm it revs like a 4 cylinder :)
The O2 sensor normally makes the engine run rich if it dies, which leads to a massive increase of fuel usage, but normally not a drop in power. Might be worth looking at, and for about $70...it's almost worth doing anyway.
Just as good practice, it might be worth checking and/or changing the transmission fluid, since it's an auto it may make it feel a bit sluggish if it's not changing properly.
As a final suggestion for now if you have an aftermarket immobiliser fitted, check all the connections for that (if you can). I had a really bad problem with my VN a few years back, one of the connections for the immobiliser was a bit dodgy, and whilst I was driving along, it would kill the left hand bank of the engine. Now...VNV6 motors can run on only three cylinders, but FU&K ME, it was ROUGH!!!
Post up with how those checks go, and we'll slowly work it out (hopefully). BTW: it's not over due for an oil change is it??? |
Bite off more than you can chew, and chew like hell - Peter Brock (1945-2006) |
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Joogie
Fully Licenced
291 Posts
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Posted - 18 Jun 2006 : 9:46:14 PM
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hey cheers for reply. Well i dont think it could be leads because they were replaced about 3 weeks ago, so i hope not they were over $50 for the set... I have not replaced my plugs since i had the car but when it was serviced they were checked but not replaced, So i will do that. As for my coil pack i know nothing about it, but i am sure it is one of those one's that you replace the old crappy single packs with.
Umm my gearbox is getting serviced next week so yeah that should help plus im thinking of puttin shift kit in at the same time:). It had a service at 213000 and its now 216000 so i think oil should be fine but then again anything could have happened.
As for my immobilisor, i have one hidden on my car that i turn on and off with a key but it will be extremely hard to access behind it as it is in a really funny place... It apparently should stop my car from being hot wired but i know nothing about that side of cars so i wouldnt have a clue. I can take it out but not for awhile as i have school for the next 5 days and no time until the weekend. I dont use it very often only when i am leaving my car somewhere unsafe... but i did use it the other day.
Cheers |
Boost me, and double clutch me so i can get my. Loss of Traction! |
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mouce
National Driver
1525 Posts
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Posted - 18 Jun 2006 : 10:19:58 PM
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The coil pack you're talking about looks like three rectangular blocks with the leads coming out of both the front and the back of the coil pack? That's the typical S1 coil pack. You're in luck though...it's a straight swap to bolt the S2 coil pack in, the one with the three separate modules (each one does two cylinders). If your coil pack has crapped itself, it's worth doing the upgrade.
At the risk of starting a bit of a debate here...I generally tend not to 'service' spark plugs, I just replace them. The chances of getting all 6 plugs out of the engine, cleaning them and re-inserting them without cracking one of them is SLIM. The heat of the engine DOES make them a little more brittle, and the torque applied to re-insert them can often crack them, leaving you with a dodgy plug. Champion spark plugs for a VN V6 cost bugger all...might as well throw new ones in just to be sure.
Unless you know exactly how the immobiliser was wired into the harness, DON'T TOUCH IT! They are designed to prevent the engine starting, and I know of many people who have just 'pulled them out' and have had to spend big bucks to get an auto-elec to find out what was killing the engine. Unless you've noticed that the engine is idling REALLY rough I think we can forget the immobiliser for now.
I know this is going to sound crazy, but the best thing that anyone with a VN can do is service it themselves. Getting hands on experience on your car is probably the best way to learn what problems are caused by which bits. Next chance you get rip down to repco, autobarn, supercheap or even KMart and find a Gregory's manual for your car (if you haven't got one already).
A quick and easy (although not entirely accurate) test for the coil pack, is go for a bit of a drive, and then carefully feel (with your hand) how hot each of the sections of the coil pack is. If one is much hotter than the other two then I think it's safe to say that we should look at that a bit more.
The reason I asked about the engine oil is that if it's become really sludgy for some strange reason (like a blown head gasket leaking water into it) it could be causing you problems. Just as something which should be done regularly (once a week is good), check the oil level and the coolant level, just to make sure that nothing is going missing. |
Bite off more than you can chew, and chew like hell - Peter Brock (1945-2006) |
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Joogie
Fully Licenced
291 Posts
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Posted - 18 Jun 2006 : 10:40:01 PM
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Hey. Well the coil pack i have is exactly like the upgrade one you have described. I have a mate with a vn and he went through that trouble and he looked at mine and said it had been done...
There is no way i am going to touch the immobilisor no that you have said that lol because i know nothing like you said and i just cant afford to pay some1 to fix it at the moment. Other things need attention before that is even considered...
The servicing will mostly be done by me but this last service was the first one since i had the car so i got the mechanic to tell me all things wrong he could find with it.... ill be doing it from now on except the gearbox because i dont have time at the moment and would rather just pay some1. Hopefully ill get my spark plugs tommoro and yes i would usually replace them as i used to race karts and no how quickly you can stuff one up(especially since i usually reved my kart to 15,000rpm)
Ill check my coil packs temp tommoro ill just leave a bit earlier before school and go for a drive then check it there...
Oh and off the topic those instructions you wrote about how to remove a raidiator will come in very handy as i am going to do it this saturday (again if i recieve less homework..lol) but was not entirly sure on how to get all the air bubbles out after it is put back on.
Cheers again |
Boost me, and double clutch me so i can get my. Loss of Traction! |
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mouce
National Driver
1525 Posts
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Posted - 18 Jun 2006 : 11:21:11 PM
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You used to race karts? That's cool. Would have been damn good fun too I bet. By the sounds of it though, you know your way around an engine fairly well, and you should have a reasonable tool kit if you did the work on it yourself, so that's a kick-arse head start on me. The last three years have been a STEEP learning curve for me with my VN.
As for getting less homework...I can remember my high-school days, I don't like your chances.
By following the filling instructions that I typed out in the other thread, the very last step, about running the engine for 20 minutes to allow it to disolve the pellets, it's in that time that any air pockets will be bled from the system, they will just end up in the coolant tank, so the level may drop a bit, keep an eye on it during those 20 minutes and it should be okay, if you're worried, check with your local mechanic.
BTW: I can understand not wanting to do the gearbox yourself, automatics suck, thought about doing a manual conversion?
Thinking about it, do you actually have the S1 the S1.5 or the S2 motor in the car? Said and done it doesn't change anything I said, but it would be interesting to know. |
Bite off more than you can chew, and chew like hell - Peter Brock (1945-2006) |
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Joogie
Fully Licenced
291 Posts
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Posted - 18 Jun 2006 : 11:36:58 PM
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Hey. Yes racing karts was damn fun because i did it on dirt and you never forget the feeling of sliding a 90 degree corner at 120km/h...its just when you crash its not that great hence the reason i no longer race. My tools unfortunatly went up north with my dad because they were mostly his but i got a few of them and have got a good collection now, though they are not the quality i had before(all sidchrome)
A manual conversion would be awesome and yes it would be done if i had the money because i feel less in control with the auto, i dont know why but i do. I know a mechanic who has a VN S2 motor thats been done up and rebuilt(all by him but i have full faith in his work and quality) and all with a manual gearbox to match which when a mate of mine wanted to buy it he said he would let it go for around $700 for gearbox and cant remember how much for motor so i thinks thats pretty good but as im in school and spent all my money on actually buying the car i have very little money and am only able to work one or two days a week.
The S1 and 1.5 have black fuel rails dont they, because i think mine are silver so thats S2? Does it say anywhere on car so i can be positive? or are there any other things to look for?
Cheers |
Boost me, and double clutch me so i can get my. Loss of Traction! |
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mouce
National Driver
1525 Posts
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Posted - 19 Jun 2006 : 08:49:13 AM
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A good tool kit rocks. I'm in a similar position to you though, all the tools that I can use are my dad's tools, and yeah...all Sidchrome. Just can't wait for him to buy an air-compressor for some air tools, that'll just make it a little bit nicer. I'm actually looking at building a rock-crawler at some point, so a garage full of tools would be essential.
You should be able to pick up the S2 motor/gearbox combo for about $1400, probably less if you shop around. At least with this motor you know that it's in good nick, since it's just been rebuilt, I think that $700 for the box alone is a good price.
Spot on with the fuel rails too. The S2 has the silver chunky fuel rails. If you're still after confirmation, check where your radiator hose runs to. On the S1 and 1.5 they run to the back of the engine, the S2 has it run to the front. These are the easiest way to tell which of the two engines you've got. Although it's not always reliable, check the build date on the plate stuck to the firewall. |
Bite off more than you can chew, and chew like hell - Peter Brock (1945-2006) |
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Joogie
Fully Licenced
291 Posts
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Posted - 19 Jun 2006 : 12:29:18 PM
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Hey yes air tools are awesome! I used them alot(like allen keys and so on) in working on my kart also used electric tools they just make it so much easier! As for the air compressor we had one but never took it we just converted a gas bottle and carried air in that. I could change 8 tyres with it and each tyre needs about 40psi to pop it onto the rim properly so it had all i needed.
Well i found out today the motor/gearbox combo is actually only $1000 so very cheap but i don't think i will be getting it.
My car was running like s#$t this morning so after school today i am going to go get spark plugs and also replace the fuel filter as i dont know the condition and i know they can lead to serious loss of power. It has good power some days and S#$thouse the next so that tells me it isnt getting the fuel is should be sometimes so maybe the filter picked up some crap. I am also going to clean the throttle body(probs remove it if time permits) and run some injector cleaner through it just because they are simple and cheap and if they dont work then i have to look deeper into the problem i suppose.
cheers |
Boost me, and double clutch me so i can get my. Loss of Traction! |
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mouce
National Driver
1525 Posts
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Posted - 19 Jun 2006 : 12:57:49 PM
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When you clean the t/b out, make sure that you clean the idle air control valve while you're there. But you do have to take the t/b out to do it.
Also...don't forget to reset the engine computer once you've done it. Pull out the engine fuse (located just in front of the coolant tank), leave it out for about a minute, then pop the fuse back in, start the car and rev it to 3000rpm for 10 seconds. Well worth doing.
Let me know how you go and we'll see what we can come up with.
$1000 for a fully rebuild engine/gearbox combo? That's a damn good price. I'm more of a fan of the S1 motor just because it's a little less 'refined' than the S2. But both are good motors. |
Bite off more than you can chew, and chew like hell - Peter Brock (1945-2006) |
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Joogie
Fully Licenced
291 Posts
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Posted - 19 Jun 2006 : 2:39:36 PM
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hey. Okay cleaning the air idle control valve, that is self explanatory what it is but where is it on t/b, on inside?
I have heard people have put V8 t/b on the v6 so 1: how much if all does this increase fuel usage and 2: is the power gain substancial enough to bother with it with the fuel usage?
I have thought about gettin a larger t/b as well but im not sure what goes well on the vn any ideas?
And the 3000rpm is not driving right? because i have done it a few times like after i shaved some of my t/b to get it to open 100% and i noticed it affected my idle but it went really low and was the idle was pretty much worse than before.. cheers |
Boost me, and double clutch me so i can get my. Loss of Traction! |
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mouce
National Driver
1525 Posts
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Posted - 19 Jun 2006 : 10:52:58 PM
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Resetting the ecu should be done while stationary, and in neutral too.
The IACV is bolted into the back of the t/b (as you see the t/b when looking from the front of the engine bay). There are two sets of electrical connections, one goes to the TPS (the bottom of the t/b), the other one goes into the IACV. Really the only way to get at it is to take the t/b out. The whole job only takes about half an hour (and that includes drying time).
When cleaning the t/b try not to let any carby cleaner run down the shaft into the TPS, they tend to not like it.
The V8 t/b on a stock V6 motor is a fairly common upgrade, as such they don't actually increase the power output of the V6, they just make it a bit more responsive at low throttle openings. Because of having a greater diameter it means that for the same 'angular' opening of the throttle plate more air can get past (spend a bit of time thinking about it). The t/b on a stock V6 flows fairly well. If you want to make it a little more responsive at low throttle percentage then yeah the V8 t/b is a good way to go.
I've also heard a rumour that the t/b from an xf falcon will bolt on (and is 2mm larger than the VNV8 one I think). Good thing about that is they should be cheap and easy to find being a ford, they tend to sit rusting in wreckers yards. But you might want to check it out before you buy it, because I don't know for certain that it will fit.
So if the xf t/b fits I'd go for that (even if it is a Ford part), simply because it's probably going to be cheaper than the VN V8 one. That said...it would be nice to have a Holden t/b on there. A few people who have way too much spare time, have actually made themselves twin t/b setups for the V6. It takes a hell of a lot of screwing around, and all sorts of welding, grinding, cutting and swearing. Sounds like fun, I've been thinking about it, but just haven't had the time or money to do it. Generally it helps to have a spare inlet manifold or two or three lying around to 'experiment' on.
With the idle after you shaved a bit off the t/b, did you remember to pull the fuse for a minute to wipe the ecu log first? Also...you may need to adjust the base idle screw, have you got a tacho (a real one, not one in the dash, I mean a good inductive one)? Base idle is meant to be 700rpm (give or take 100rpm) measured in neutral. Holden say it's non-adjustable, but there's a little throttle stop screw you can use to adjust it a bit. Don't go playing with it unless you have an accurate tacho though. |
Bite off more than you can chew, and chew like hell - Peter Brock (1945-2006) |
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Joogie
Fully Licenced
291 Posts
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Posted - 19 Jun 2006 : 11:28:29 PM
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Hey. Yeah i get all the stuff about the t/b it makes sense that if the butterfly is bigger more air will be let by. A more responsive throttle would be very good and i would love it so its now on my list of things to do...
My CAI should give it a bit more from what i have heard(well from what i know) though it is not a holden one rather one i have made myself from zinc coated sheeting, pop rivets, solder and a lot of patience! Im hoping it has the same effect as the holden one's and i see no reason why it should be any differant.
Yeah i have a very accurate electronic tacho that i could hook up but i dont really know how apart from putting it on each plug lead...If i need another more accurate tacho than the one i got i have friends with all the fancy **** at my disposal... I have the money for the tacho now but i dont like any of the ones i the shops aroung here atm all 5" monsters and i would prefer a 3". Setting idle should be ok if it is touchy because there is no way it can be worse than my kart was...1/2mm to far and all hell could break loose.
When i did the t/b shaving i did take out the fuse for about 2 minutes and then reved to what i thought was 3000rpm or over but the car was in park not neutral.
And i have also heard there is a part near the t/b that can be removed or a bit shaved off for some extra power, is there any truth to this? |
Boost me, and double clutch me so i can get my. Loss of Traction! |
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kempo
P Plater
56 Posts
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Posted - 05 Jul 2006 : 10:22:29 PM
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Umm Maybe check that your fuel pump is working properly. Umm start your car turn it off and listen for a whiney noise from the rear of your car. If the noise goes for longer then say 4-5 secs might wanna get new or second hand fuel pump. i got a second hand one for $50 problem solved.
Kempo. |
Get back in ya box idiot! |
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