91 Vert with misfire
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Joined: May 2005
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91 Vert with misfire
My bone stock l98 has developed a misfire. I believe it is in the TPIS system, injectors most likely. All eight were replced with facotry new ones in 2001, but the car mainly sat until I got my baby late last year. Does anyone know the name of and where I might get the Fuel Injection cleaning product that comes in a compressed can you connect to your shredder valve and pull the fuel pump fuse? The car runs on the stuff in the can and cleans the injectors. I would really rather do this myself than let the dealer do it for me. 
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If you have an ignition misfire,get a timing light and hook each plug wire up one at a time and see if there are pauses in between the flashes as the car runs.If you find some,you need to check the plug,wires,or etc.
Plugs/wires that dont miss,the timing light flashes all the time,gets faster with rpms,slows down with rpms...a wire or plug thats misfiring,will flash and have a bunch of pauses between them.
I dont know why from your post you feel to use injector cleaner?Did you find any injectors that checked out fine hot and cold but might be sticking and not spraying fuel?
Plugs/wires that dont miss,the timing light flashes all the time,gets faster with rpms,slows down with rpms...a wire or plug thats misfiring,will flash and have a bunch of pauses between them.
I dont know why from your post you feel to use injector cleaner?Did you find any injectors that checked out fine hot and cold but might be sticking and not spraying fuel?
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Like the above poster, I agree it could be your ignition coil and wires.
For a low-tech solution, you can also open the hood at night or in a darkened garage with the hood lamp fuse disconnected and look closely for arcing and other telltale electrical "creepycrawlies" along your wires.
You can also mist the wires with a spray bottle, too, to identify any "gremlins."
For a low-tech solution, you can also open the hood at night or in a darkened garage with the hood lamp fuse disconnected and look closely for arcing and other telltale electrical "creepycrawlies" along your wires.
You can also mist the wires with a spray bottle, too, to identify any "gremlins."
Racer
Joined: Apr 2007
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From: edmonton alberta
Like the above poster, I agree it could be your ignition coil and wires.
For a low-tech solution, you can also open the hood at night or in a darkened garage with the hood lamp fuse disconnected and look closely for arcing and other telltale electrical "creepycrawlies" along your wires.
You can also mist the wires with a spray bottle, too, to identify any "gremlins."
For a low-tech solution, you can also open the hood at night or in a darkened garage with the hood lamp fuse disconnected and look closely for arcing and other telltale electrical "creepycrawlies" along your wires.
You can also mist the wires with a spray bottle, too, to identify any "gremlins."
Last edited by etown brawler; Jul 13, 2007 at 08:23 AM.
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Joined: Oct 2006
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From: Franklin indiana
What kind of misfire is it? My 90 convertible sometimes backfires repeatedly through the exhaust, kind of pop-pop-pop when I accelerate at all, doesn't do it at idle, also it always sounds kind of flat, like a cylinder isn't firing. Last time it happened it was after idling for a long time after a fireworks show. It smokes and runs rich also, so I think it might be injectors, as cap and wires are fairly new MSD's. Would a bad ignition module or coil do that?
Last edited by billvh; Jul 13, 2007 at 10:08 AM.
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Well, after reading the replies I realized I had forgotten to list what I have already replaced. Cap, Rotor, Plugs and megged the wires. I found the stuff at NAPA I was looking for and it did the trick. Found lost power and pures like a kitten. Thanks for the help, this is always the first place I turn to. 
billvh - In my experience and humble opinion, when an ignition module goes bad the engine dies abruptly and it is gone until the module is replaced. Since you have replaced most of the ignition already I suggest cleaning the injectors if for nothing else than to eliminate them from the equation. Napa sells the stuff in a can that I used, but you can also take it to any dealer ( I have done this also with great results) and they can do it as well. A slightly cheaper route for the injectors to begin with is to put a can of Seafoam in the tank first and wait for any symptoms to change.
billvh - In my experience and humble opinion, when an ignition module goes bad the engine dies abruptly and it is gone until the module is replaced. Since you have replaced most of the ignition already I suggest cleaning the injectors if for nothing else than to eliminate them from the equation. Napa sells the stuff in a can that I used, but you can also take it to any dealer ( I have done this also with great results) and they can do it as well. A slightly cheaper route for the injectors to begin with is to put a can of Seafoam in the tank first and wait for any symptoms to change.
Last edited by HGN CRVZ; Jul 14, 2007 at 09:36 PM.
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From: Franklin indiana
I have the original injectors; it now has LT1 injectors in it, so I think I'll put those in and see how it does. One thing I did notice, is that number one on the cap isn't where I'm used to seeing it. It is at about 1 o'clock if you're facing the cap. I don't think that would matter if the firing order is right (which it is), unless it might be a tooth off. I might re-time the distributor and see if it is correct. It doesn't backfire all the time, so I don't think thats it though.
