no, it's N/A
Misfire ?? Help Needed
- Thread starter madbrian
- Start date
no, it's N/A
i would not be concerned about that,if it had that much water in the tank to run bad,it would pretty much run terrible all the time- but you do need to drive it with a fuel guage hooked up and rule the fuel pressure out,it will help put you in the next direction
Madduc
Enthusiast
Maybe re-check/adjust the throttle body sync again?
My car has some bucking issues. 95% at low speed (under 2,000rpm) and it's because of the 708 cam installed in my car. The 708 cam (96-99) idled rough and had a tendency to 'buck' often while attempting to drive easily. I have an aluminium flywheel which makes the budking worse. The 2000 Vipers got a cam change because of this. I drive 'around' the surge/bucking and seldom notice it as I drive in lower gears and with more throttle to try and stay away from the bucking.
You didn't say when this problem started to occur of if the car always had this problem?.
Ted
You didn't say when this problem started to occur of if the car always had this problem?.
Ted
As a point of reference, I have a 97 and I have the same issue that you pointed out, however, when the car was stock it did not buck. My problem came when I installed larger injectors and the VEC. I have eliminated most of it with the SCT tuning software and hopefully I will eliminate the rest of it this spring.
i have checked for audible and visual signs of a leak.
is there an easy way to discover vaccum leaks?
i replaced my 99 pcm for a brand new 98 pcm.
do you know if the 98 pcm checks for misfires etc?
thanks!
the car has always had this problem since i owned it but i had it when it was 5 year old with 10,000 miles.
GTSnake
Enthusiast
My car bucks and stutters only when it's cold. But after it warms up it goes away.
A dangerous way is to spray EXPLOSIVE ether at all the vacuum lines and see if the idle changes (works around bottom of intake manifold too). The safer, although not as efficient way is to spray a water/soap mix on all vacuum lines and see if the idle slows (meaning that the water sealed the leak or watch for airbubbles (possible).
Ted
Larry Macedo (M2 Motorsports) told me that I have a 96 ECU because it is the only one that doesn't record misfires. All other ECUs throw misfire codes.
Ted
A good tuner (like Larry Macedo, Dan Cragin, Sean Roe and others could probably take a good OBD reader and watch the readings while the car was bucking on the dyno and tell you what the problem is (fuel, spark, etc.). Interesting that although fuel has been mentioned as suspect, you didn't write what readings you got from the spark plugs???
Most dyno shops will also have a spark illuminator that connects bewteen the the wire and the spark plug that lights when the plug fires. No spark, no light.
What tuner shops have tried testing your car?
Ted
Most dyno shops will also have a spark illuminator that connects bewteen the the wire and the spark plug that lights when the plug fires. No spark, no light.
What tuner shops have tried testing your car?
Ted
unfortunately i am in the UK and have no knowledge of any tuners with any experience of vipers so i am struggling to get it sorted.
thanks.
[email protected], is Larry Macedo's email (M2 Motorsports) but it seems like you probably need a reader and someone with the experience to know what the readings mean. Chuck Tator does a lot of UK business so call Tator's Dodge and ask Chuck who you should take your car to over there. Chuck must send them a lot of parts. Another site sponsor that would send parts there and should know UK tuners is JonB at [email protected]
Ted
Ted
take a can of brake clean or parts cleaner and spray along and around the intake manifold where it meets the head(with the engine running). If there is a slight leak, the idle will change. It not uncommon that sometimes the intake gaskets leak without ever hearing a whistle. Also check to make sure that there isn't a pin hole in the rubber 90 degree boot that connect the MAP to the intake manifold. Another place to check is where the two emissions hoses connect to the front of the intake underneath where the throttle bodies sit.
The reason why im stuck on a vacuum is when you say you go WOT (wide open throttle) the problem goes away. Under WOT the MAP is reading -.8hg to -.4hg. At that point the vacuum leak isn't going to matter.
Also you state in your first post ( both cats ( 1 damaged through misfire ) ) The thing that kills the cats is when a car dumps fuel. If your cruising or moderately accelerating that's when a slight vacuum leak can have the most effect.
I'm horrible at explaining things in an efficient and thoroughly fashion, due to I have A.D.D. So if something doesn't make sense please tell me to re-explain
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take a can of brake clean or parts cleaner and spray along and around the intake manifold where it meets the head(with the engine running). If there is a slight leak, the idle will change. It not uncommon that sometimes the intake gaskets leak without ever hearing a whistle. Also check to make sure that there isn't a pin hole in the rubber 90 degree boot that connect the MAP to the intake manifold. Another place to check is where the two emissions hoses connect to the front of the intake underneath where the throttle bodies sit.
The reason why im stuck on a vacuum is when you say you go WOT (wide open throttle) the problem goes away. Under WOT the MAP is reading -.8hg to -.4hg. At that point the vacuum leak isn't going to matter.
Also you state in your first post ( both cats ( 1 damaged through misfire ) ) The thing that kills the cats is when a car dumps fuel. If your cruising or moderately accelerating that's when a slight vacuum leak can have the most effect.
I'm horrible at explaining things in an efficient and thoroughly fashion, due to I have A.D.D. So if something doesn't make sense please tell me to re-explain
Another view: if you have a vacuum leak, the IAC will try to correct it by closing. At some point the IAC will close to a point where I believe it will set a soft code. You could also use a code reader to monitor the IAC position.
no.i would have to travel too far.
take a can of brake clean or parts cleaner and spray along and around the intake manifold where it meets the head(with the engine running). If there is a slight leak, the idle will change. It not uncommon that sometimes the intake gaskets leak without ever hearing a whistle. Also check to make sure that there isn't a pin hole in the rubber 90 degree boot that connect the MAP to the intake manifold. Another place to check is where the two emissions hoses connect to the front of the intake underneath where the throttle bodies sit.
The reason why im stuck on a vacuum is when you say you go WOT (wide open throttle) the problem goes away. Under WOT the MAP is reading -.8hg to -.4hg. At that point the vacuum leak isn't going to matter.
Also you state in your first post ( both cats ( 1 damaged through misfire ) ) The thing that kills the cats is when a car dumps fuel. If your cruising or moderately accelerating that's when a slight vacuum leak can have the most effect.
I'm horrible at explaining things in an efficient and thoroughly fashion, due to I have A.D.D. So if something doesn't make sense please tell me to re-explain
i just stripped all the visible vacuum pipes off the car, examined and replaced most with new ones in case including the map elbow and other elbows.
small diameter silicone hose worked well as elbow replacements.
i also re torqued the inlet down .
result-- still the same but the car seems more powerful when i give it gas.
if it was only 1 injector, would it make the car buck and miss badly up to 3000 revs?
also would it show a code?
thanks.
Fatboy 18
Enthusiast
Hello Brian, So where are you roughly in the UK?
Are you the same Brian I met at Le mans last year?
Mark
Are you the same Brian I met at Le mans last year?
Mark
Hello Brian, So where are you roughly in the UK?
Are you the same Brian I met at Le mans last year?
Mark
hi Mark, not me, i have never been to Le Mans.
i was living near Birmingham but had to move to west wales due to work
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