Misfiring Issues

[dbh2002]

OK,

My S2K is constantly having misfiring issues and it will appear randomly. It can idle fine for 15 mins and then start to run rough and throw the CEL. I have had new injectors installed, (there apparently was metal in the fuel filter and in the gas tank filter. It has a vortech supercharger and the FMU and the system has checked out fine. The place that is trying to diagnose the problem has been on some Honda forums and apparently others have had same issues. This is really frustrating and any help here would be appreciated.

[s2k_at_17]

i had some misfiring codes sent on my S too. we took it to Honda and they said that it was the valves..i dont know if your guys have check that out but if not just ask...hope the issue gets solved

[dbh2002]

What did it take to solve the problem? This engine only has 12K on it and it was driven by a 66 year old man I met personally. The car has never been abused. Valves sound like major surgery. Already spent $700 and still in the shop.

[photodavo]

I'm sure Dave (repiv) will reply when he sees this. He has an '00 that is Vortech supercharged and is also one of our resident mechanical experts. If you would like, I can move this to his own technical forum "The XViper's den" where he will be sure to see it.

[s2k_at_17]

they replaced the valves, and valve gides and had to send the head off to the shop to make sure that it wasnt cracked and had re-surfaces.

[dbh2002]

Thanks Davo,

Please move the message onto XViper's den. Hopefully he can help. I can even have the shop call him and they can explain what they have done to solve this problem. It may help out other members with similar issues. DID racing in Crestwood IL are a registered Vortech dealer and they are a little baffled at this point.

[photodavo]

Thread moved...

[repiv]

Misfire codes can be extremely difficult to resolve on a stock car, but on one with a Vortech, it can be doubly difficult. There are so many things that could be at fault. First, you must eliminate the S/C as the thing at fault. A lot of wires got cut and more got spliced into when the 2 Vortech black boxes were added. Now, has this situation existed since you got the car? If so, this may mean that the Vortech may have been installed incorrectly to begin with. Other than a visual, do you know exactly what the shop did to determine that the kit "checked out fine"? Does the shop know that the written instructions for the black box wiring is WRONG? Do they know that ONLY the wiring diagram is correct? Quite a few Vortech installers, both shops and the owners have made this mistake in the past. ALL wiring connections must be examined and cross-referenced with the wiring diagram ONLY. IGNORE the written stuff. Then, ALL wiring connections and splices must be checked carefully to determine solid continuity. Connections may "look" OK, but unless they have been soldered or each one crimped 2 to 3 times, they can degrade, giving weird conditions like misfire codes. A "registered" Vortech dealer doesn't always know specific applications on specific types of cars. For example, lots of Honda and Acura dealers were authorized dealers for Comptech superchargers and I can tell you that some of these had absolutely no clue. I bought mine from a "registered" Canadian Vortech dealer. He didn't have a clue how to install one. He only sold them. He never installed one.
Then there's the possibility that the MAP sensor has become damaged or clogged with oil vapours. Some supercharger kits, especially those not using catch cans, can push through a lot of oil vapours past the MAP sensor. Also confirm that the MAP sensor connector is solid. Does the shop know that Honda issued a TSB for a new MAP and securing system for this car some years ago. This is a very finicky connection and is subject to a lot of vibration. Honda came up with a fancy zip tie to hold it securely in place.
Once you've gotten the above sorted out, then you must treat the misfire condition just like you would a NA engine. You can do the following in whatever sequence suits you and take the necessary next step depending upon what the outcome is ......................
- the coil packs must be taken out of the equation. Shuffle them around from one plug to another and see if the misfire moves to another cylinder. You may have one or more bad coil packs.
- shuffle the injectors around to see if the misfire moves. You may still have one or more injectors not performing to spec for different reasons.
- check your spark plugs for the correct type, torque and gap for supercharger duty.
- check the fuel pressure at the fuel rail. Maybe you have an obstruction in the line. You say you found metal in the "fuel filter" and the "fuel tank filter". I'm confused by this statement since both are one in the same. There is only one such filter. Who is telling you that you have "both"?
- then there's the worst case scenario ...................... bad ECU.

Base on what you've said, I doubt a car with 12K miles on it, will be in need of a valve adjustment, considering you say the car has never been "abused". The fact that it was driven by an "old" man doesn't necessarily mean it wasn't driven hard nor does it mean that he drove it in such a way so as to promote a misfire. It also doesn't necessarily mean that even if he did get a misfire condition, that he did anything about it (since it's a random and temporary thing) or that he would tell you about it. Some of us "old" guys can be pretty sneaky. :o

If I were in your situation, I would start with a complete and thorough diagnosis of the supercharger kit. What year of car is it? I'm thinking that a car with only 12K miles on it would not "normally" show up with misfire codes. Usually, this sort of thing happens when you do something to it (like add a supercharger).
Calling me on the phone won't work so well as I can't take such calls when I'm working and my work schedule is based on an 8 day week, not your typical Monday to Friday kind of thing. Just have those things checked out as I've listed, beginning with the Vortech wiring and MAP.

[dbh2002]

Thanks for the help and suggestions xviper. It turned out that the wiring going to the injectors was cut and then spliced back together with connectors that were loose. The car would run fine and the owner of the shop was not going to give up and he knew it had to be electrical because it would run fine and then when he went over some railroad tracks it would start to misfire. Just like you said, all the wiring needs to be checked out! They installed a new wiring harness and wires to the injectors and now the car runs like a champ. Did it need injectors?? Hard to say really, not sure were the fine metal fragments came from, but they showed me the old injectors and they were clogged. They replaced the fuel filters inside the gas tank etc to make sure everything was clean. I only just got this reply from you but it was exactly as you described...it was a nightmare trying to diagnose this problem but it is fixed now and I am relieved.

Daryl

[photodavo]

The XViper strikes again! :thumbsup:

Thanks so much for helping out so many Dave!