swept Posted October 17, 2012 Report Share Posted October 17, 2012 Hello all, new member here enjoying this forum. I recently have acquired two 505's (N9T) both of which need some tuning. when I try adjusting the airflow sensor (by the allen key screw) to achieve the 7.2 volts required (according to the manual), the voltage doesn't change from 7.98. I thought perhaps it was the sensor so I installed another one (used) but the problem is unchanged. does this mean there is a leak in the air intake system somewhere? thanks for any input, Ken. Quote Link to comment Share on other sites More sharing options...
Bean Posted October 17, 2012 Report Share Posted October 17, 2012 Hi Swept, Using a used O2 sensor isn't a really good test as it's still an unknown. You really should use a new O2 sensor - but that being said - what are the other symptoms? What other things have you done to tune the car? Rabin Quote Link to comment Share on other sites More sharing options...
Bean Posted October 17, 2012 Report Share Posted October 17, 2012 BTW - the VAF to turbo intake hose is known to split, so you might want to check that. More info on what the symptoms are would help to diagnose it though. Rabin Quote Link to comment Share on other sites More sharing options...
swept Posted October 17, 2012 Author Report Share Posted October 17, 2012 thanks for the replies Rabin. The vehicle is running lean, not terrible, but just enough to warrant some attention. no flashing light comes on, it just doesn't idle very smoothly, especially when cold. runs great when hot. I checked the workshop manual and the advice was to start with adjusting the airmass sensor at 950 rpm, reducing the voltage is supposed to enrich the mixture. ( this is just a new found hobby so I am relying fairly heavily on the manual). I will check the hoses for cracks more carefully. another more important problem is a possibly blown head gasket....I didn't think that oil could leak from the head, but that is what looks like is leaking out of the passenger rear corner side of the head (lowest point ). It is definitely not coolant leaking there, but there is coolant loss somewhere...I gather the head gasket can be a problem from my reading on this forum. Ken Quote Link to comment Share on other sites More sharing options...
Bean Posted October 19, 2012 Report Share Posted October 19, 2012 You may want to make extra sure the oil isn't coming from the valve cover just to be sure. It's possible for the HG to leak oil, I don't think I've seen it before. What is quite a common failure for these heads however is for the head to crack between the exhaust valve and the coolant chamber on the #2 and #3 cylinders. This allows engine compression into the coolant system which usually blows rad hoses or separated rad tanks. Tell tail for this is bubbles into the coolant reservoir. I suspect my 89' is starting to have a cracked head as I have seen bubbles in the coolant reservoir, but it's not consistent. As for your running lean issue - Victor Van Tress had what appeared to be symtoms of a vacuum leak but none of the usual checks would confirm it. He ended up having the intake manifold gaskets changed and all was well. Something to consider at least. Rabin Quote Link to comment Share on other sites More sharing options...
swept Posted October 20, 2012 Author Report Share Posted October 20, 2012 I think I will try changing the intake manifold gasket first. I may have to get down to the head, since there is definitely internal coolant loss, and the oil is not leaking from the valve cover. thanks for your help, Ken Quote Link to comment Share on other sites More sharing options...
Bean Posted October 20, 2012 Report Share Posted October 20, 2012 If the head is cracked, then getting a proper and thorough fixed head from Erikkson or from a proper shop familiar with this kind of crack repair is essential. Check the coolant reservoir for bubbles with the engine running - if there are bubbles I'd then focus on the head repair. It's actually a fairly common occurrence for a number of manufacturers, and engines - and the repair isn't too bad cost wise if you can do the work yourself. ($1100 IIRC from Erikkson for totally rebuilt head) Rabin Quote Link to comment Share on other sites More sharing options...
swept Posted October 22, 2012 Author Report Share Posted October 22, 2012 not much in the way of bubbles, but there is a lot of black flecks (carbon?) in the coolant reservoir. I'll let you know what I find. thx, Ken Quote Link to comment Share on other sites More sharing options...
swept Posted February 20, 2013 Author Report Share Posted February 20, 2013 managed to get the head off and inspected at a machine shop...multiple cracks that apparently have been welded before. I have another cylinder head, but am having a very hard time finding a new exhaust manifold gasket...do you know of anyone making these gaskets (e.g. custom)? thanks for any help, Ken Quote Link to comment Share on other sites More sharing options...
Bean Posted February 25, 2013 Report Share Posted February 25, 2013 Is there a reason you can't reuse the old one? I've reused them with no issues before, so you might want to try that. Going forward I was thinking I may look at having some done up on a waterjet machine cutting them out of copper sheet - but that's a ways off. Might be able to contact someone local however - they usually just need the old gasket and they can use that as the pattern. Rabin Quote Link to comment Share on other sites More sharing options...
swept Posted March 2, 2013 Author Report Share Posted March 2, 2013 thanks for your response Rabin, I have reused the gasket but still have an exhaust leak so I sent an old gasket to Cometic gaskets and they are making up a new one. cylinder heads are another issue. I have two heads, both with cracks, so I am now sending them off for repairs. I am looking forward to getting this done Quote Link to comment Share on other sites More sharing options...
Bean Posted March 2, 2013 Report Share Posted March 2, 2013 http://www.505turbo.com/forum/index.php?/topic/2509-n9te-head-intake-and-afm-with-housing-available/ Peter has a head that appears to be good, might be worth you getting it rather than me if you need it. Save you a ton of money for other things, plus he's way closer to you. I'll snag it only if no one needs it. Rabin Quote Link to comment Share on other sites More sharing options...
swept Posted March 3, 2013 Author Report Share Posted March 3, 2013 thanks very much for the info Rabin, I will contact Peter...he's only 2.5 hrs drive away. thx, Ken Quote Link to comment Share on other sites More sharing options...
swept Posted May 15, 2013 Author Report Share Posted May 15, 2013 thought I would update...after some welding new cylinder head installed. runs beautifully...but no clutch. not willing to believe I screwed up, I played with bleeding the system and finally decided I had screwed up and it was a mechanical not hydraulic problem. pulled the engine again and found that i had installed the clutch disc backward...that's embarrassing but at least a cheap (if labourious) fix. I am grateful for the extra cylinder heads, but all of them have cracks. next project is to rebuild another engine for the second 505. so hopefully the heads can be welded. thanks for all of the posts on the forum...they have been extremely helpful Quote Link to comment Share on other sites More sharing options...
Bean Posted May 15, 2013 Report Share Posted May 15, 2013 Glad to hear you were able to get it all right and functional! Despite the set backs - that first drive when it's all working is a great feeling. I would say the heads are definitely repairable, but finding someone that can do it right for a reasonable sum is the tough part. I've got a few cracked heads that I'd like to sacrifice with some destructive investigation to see exactly how deep and where they are cracking to figure out the best way to fix - but like everything else - it's very far down the todo list. Rabin Quote Link to comment Share on other sites More sharing options...
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