Is this guy a genius or an idiot?

[JSecrest]

My comptech sc NSX is in the shop. I have been having problems with hot start stalling and erratic idle. These guys are not NSX or even Honda specialists but build some turbocharged engines. They did some work on my regular cars so I thought I would have them take a quick look at the NSX. The head of the shop was out today and when I called, one of his guys was working on the car. He was doing a spark plug change when I called. I had just come across the page in my comptech sc installation manual where they had a diagram showing the vacuum hose set up which is different from the factory set up. It occurred to me that if those hoses are not set up properly, it could be causing the types of issues I have. So I asked the mechanic if I could send him the diagram so that he can check it out. He got upset with me, said he had his own order for going through and diagnosing a car (he said he was the mechanic) and after the spark plug change, he would then check the fuel pressure. He was not at all interested in seeing the diagram and said if he needed it he would get it off the Internet. (I couldn't find one there with a quick look). I was floored that he was not at all interested in the diagram. My car has had these problems for a long time and it is entirely possible that these hoses are wrong or have been put back in stock configuration.
Am I wrong in thinking that the vacuum lines could be the problem and that without the diagram it would not be obvious to a mechanic how they should be set up? Could he possibly be right or am I dealing with someone with a screw loose?

 

[DocL]

Pick up the car and bring it to Dwight in Ft. Lauderdale.

 

[chudson1549]

See above for sure

 

[Jinks]

Get the keys back and run quickly if your car can....
Being in west palm beach, is this by any chance treadstone? I dealt with them previously on turbo kits. If so, run.... Run fast.......

 

[jimminh]

could be the bypass hose, mine was collapsed, yours might be cracked, letting in too much air...it's the tube that heads down under the blower, can't see it without an inspection camera. on the end of the metal tube they used a cheap rubber hose to connect to the vacuum controlled valve. the hose fails after several years, some collapse due to the vacuum, others crack and leak. doesn't sound like your mechanic is interested in suggestions though...

 

[JSecrest]

could be the bypass hose, mine was collapsed, yours might be cracked, letting in too much air...it's the tube that heads down under the blower, can't see it without an inspection camera. on the end of the metal tube they used a cheap rubber hose to connect to the vacuum controlled valve. the hose fails after several years, some collapse due to the vacuum, others crack and leak. doesn't sound like your mechanic is interested in suggestions though...

Thanks for the suggestion. I've never heard of an inspection camera although it sounds quite useful. Do many shops have them?

 

[kingtal0n]

Hey there, I am located in south florida and would looooovee to look at your car, completely free of course, and I will examine ALL of your diagrams and memorize the entire FSM if necessary.

I have been diagnosing cars and going fast since I was 15 years old. You can stand there while I look it over and I will explain and teach you what I am doing and why!!

I am located by copans and lyons , probably fairly close to you

- - - Updated - - -

Thanks for the suggestion. I've never heard of an inspection camera although it sounds quite useful. Do many shops have them?

For instance, to this end, if any of the air path is leaking it will show up when you pressurize the plumbing to 15psi by using an air compressor. This is a traditional test called a "boost leak" test and necessary when you own a MAF based car because each "grain" (molecule) of atmosphere is accounted for.

 

[jwmelvin]

Erratic idle with CTSC is most likely a leaking bypass hose, as mentioned above, or a dirty throttle body. Addressing both of those helped my car out when I first got it.

 

[DDozier]

What year is your car? I am guessing you have a 91-94 car based on your issue. PS - add the year of your car to your signature it will help others help you should you have any future questions about your NSX.

The CTSC system will not run properly if the vac lines are not changed to match the CT diagram, that being said if you have been driving the car for some time with everything being fine and the idle and warm start issues just started showing up it is unlikely that the vac lines are the issue.

In DBW NSXs (95+ cars) your issues are likely the bypass hose, clogged vac line to the MAP sensor, or a very dirty throttle body.

In cable throttle NSXs (91-94 cars) you issues are likely the bypass hose, clogged vac line to the map sensor, clogged on malfunctioning IAC, or dirty or clogged idle air passages in the throttle body.

It is possible there are other issues like clogged or leaking injectors or partially clogged catalytic converters but these items will have a much larger effect on the cars performance than just idle or startup.

If you talk to your tech or his boss and tell them that these are the items of concern to check first as they are the most likely to be the issue and he still wants to change your plugs, replace fuel filter, replace fuel pump, replace air filter, replace wiper blades, replace gas cap, replace coil packs, replace belts, all he wants to do is replace parts and send you a big bill. I can respect a tech having a process to diag an issue but one of the steps if not the first step in the process is finding out the most common faults in a particular system and ruling those out first before you start replacing every part on the car. You are not the first owner of a CTSC car to have this issue, it is well documented here on Prime, easy to search for using google, and now you even have your own thread to show the guy. If you still have faith in the shop then print this out and take it to him before you authorize any additional work.

Dave

 

[jimminh]

Thanks for the suggestion. I've never heard of an inspection camera although it sounds quite useful. Do many shops have them?

I meant something like this...
[h=1]http://www.homedepot.com/p/Milwaukee-M12-12-Volt-Lithium-Ion-Cordless-M-Spector-360-Digital-Inspection-Camera-Kit-2313-21/202932657?N=5yc1vZc2gm[/h]I've got a cheapo Harbor Freight version, which has a detachable tiny LCD display.. makes it easy to get a wrench on hidden bolts... any decent shop should have something like lying around.

 

[LMR]

Since it's been happening for a long time then it's the vacuum hose procedure in the CT instructions that needs to be done.

 

[jwmelvin]

I wouldn't have thought that switching vac lines #3 and #4 would affect idle, only behavior in boost.