Engine misses some backfiring

slitherv10 · Mar 17, 2012

Hi everyone,

I have a 1996 GTS and just took out the viper for its 4th ride this year after a 4 month storage. I noticed when i would be warming it up especialy, that it had a slight miss in the engine. As I started to drive it, it would slowly go away but occasionaly I would feel the missing. On the last ride i noticed big time hesitations on start up and during the ride, and lots of backfiring. I noticed that the drivers side of the motor was not as hot as the passengers side around the heads and the headers. I felt all the ignition wires and noticed that one of the wires ( drivers side closest to the driver) was cold. The others on the same side got hotter as you moved toward the front of the car. The passengers side ignition wires were very hot and so was teh heads and headers. From the rear exhaust you could feel the drivers side pipe had cooler exhaust than the passenger side exhaust fumes which were much hotter.

What do you think may be the problem and how can I fix this ?

Thanks

uvbnbit · Mar 17, 2012

Original plug wires? How old are the plugs? Heat shields or socks around the plug boots?

slitherv10 · Mar 17, 2012

The plugs are the champion RC12LYC. Not sure how old they are as I purchased this Viper last year with these plugs wires and everything else. Didnt do anything to it when I got it other then oil changed , New optima battery and TB sensor changed. Sorry not very savvy mechanicaly. It has these round metal tubes that slip on top of the spark plugs. Im guessing these are the heat shields?

What I am noticing is that the drivers side part of the motor is staying cold and the exhaust coming out of teh drivers side is cold as well. It is only backfiring when I give it some gas. Otherwise when idiling it just misses and bogs. Every now and then when i give it more throttle it makes a popping noise in teh engine area.

Steve-Indy · Mar 17, 2012

"What I am noticing is that the drivers side part of the motor is staying cold and the exhaust coming out of teh drivers side is cold as well."

While I am not a mechanic, I can say without hesitation: Please STOP driving your Viper until a Tech looks it over. Sometimes it's better to ride a flatbed than to take chances of causing more harm. Best of luck !!

plumcrazy · Mar 17, 2012

if one side is hot and the other cold. might be a clogged cat ?

uvbnbit · Mar 17, 2012

No CEL's ? (check engine light)

bluesrt · Mar 17, 2012

could be hung injector from sitting, and leanpoping

slitherv10 · Mar 17, 2012

uvbnbit said:
No CEL's ? (check engine light)

No Check engine light on. I did however pull out wire number 3 and noticed it was not clicked into the distributor. Loose fit. I took it out and looked inside head of the wire boot and noticed it had a rusted brown color finish instead if the clean silver metal look. I'm guessing it was sparking because of the loose connection to the distributor

Can one bad wire or plug cause one side of the motor to run cold and misfire/ backfire. ?

uvbnbit · Mar 18, 2012

Not sure, but I think the upstream O2 sensor would adjust fuel/timing/injector pulse, etc for all 5 cylinders based upon what it is sensing from the "4", so yes, I think it's possible the whole side could run as you mention. Once you fix/replace that loose wire, I would think you'd see a considerable difference

whitebluevipe · Mar 18, 2012

i had a backfire it mine. bad plug. just a guess. i would pull plugs and take a look.

moparracing · Mar 18, 2012

uvbnbit said:
Heat shields or socks around the plug boots?

are the socks around the plug boots necessary when running headers on a NA engine?

slitherv10 · Mar 18, 2012

moparracing said:
are the socks around the plug boots necessary when running headers on a NA engine?

If they are ceramic headers, I believe youcan get away with not using them. If they are stainless steel naked headers, then you would for sure. You could rap them as are mine but, I still get extreme heat in the wire area. Best to put them on anyway. No loss and they look good.

slitherv10 · Mar 18, 2012

uvbnbit said:
Not sure, but I think the upstream O2 sensor would adjust fuel/timing/injector pulse, etc for all 5 cylinders based upon what it is sensing from the "4", so yes, I think it's possible the whole side could run as you mention. Once you fix/replace that loose wire, I would think you'd see a considerable difference

I ordered new plugs and wires from JonB at Parts Rack yesterday, along with socks. Jon suggested the Mopar Oreca High temp Performance wires and socks.

slitherv10 · Mar 18, 2012

plumcrazy said:
if one side is hot and the other cold. might be a clogged cat ?

If it wre a clogged Cat I would think the motor would run hot and the exhaust would put out cold exhaust. In my case, the drivers die engine block and heads,wires etc are running cold and the exhaust side as well.

?? no

AZTVR · Mar 18, 2012

Well, the new wires plus plugs are the exact right thing to do first. Let us know what happens, and then go from there. If that doesn't do it, it sounds like time for a tech. If you are into shotgunning it, then the advice above about injectors is another shot at it that you could do and not be a waste of money (IMHO.) Pull the injectors and send them out to get them cleaned. Couldn't hurt on a 16 year old car ! They will get cleaned and flow tested. I remember that 1TONY1 was doing that service. I has some done by a different shop some years ago BV (Before Viper) and they provided flow rates from testing before and after cleaning; so, that really made you feel like your money was well spent !

Dan Cragin · Mar 18, 2012

I think you have made the right call on the plugs and wires. Here are a few tips. If you have access to compressed air then blow all the dirt and dust from around the spark plugs when you remove the wires. This keeps dirt from falling into the spark plug hole. When installing the new plugs use some lubricant on the threads (anti-seize is best). When installing the new wires, put a small amount and dielectric grease in the boots on both ends (this will stop the corrosion). You can use some silicone spray as well if the boots do not "snap" on. You want to hear an audible noise. Make sure you slide the spark plug boots all the way up. Replace the old brittle spark plug wire holders with the 2000+ snap type holders.

Hope this helps.

AZTVR · Mar 18, 2012

DC Performance said:
Here are a few tips. If you have access to compressed air then blow all the dirt and dust from around the spark plugs when you remove the wires. This keeps dirt from falling into the spark plug hole. When installing the new plugs use some lubricant on the threads (anti-seize is best).

I would add that I've heard that it should be a very small amount of anti-seize and not on the first couple of threads. Some people get carried away with it.

moparracing · Mar 18, 2012

DC Performance said:
Replace the old brittle spark plug wire holders with the 2000+ snap type holders.

do you have a source where to get these?

uvbnbit · Mar 18, 2012

uvbnbit said:
Not sure, but I think the upstream O2 sensor would adjust fuel/timing/injector pulse, etc for all 5 cylinders based upon what it is sensing from the "4", so yes, I think it's possible the whole side could run as you mention. Once you fix/replace that loose wire, I would think you'd see a considerable difference

Nevermind this statement. I've got my O2's repositioned to the header collector. Your O2's ought to be in the #5 and #6 exhaust tube and therefore making adjustments based only on that cylinder. Sorry for confusion (mine)

slitherv10 · Mar 18, 2012

uvbnbit said:
Nevermind this statement. I've got my O2's repositioned to the header collector. Your O2's ought to be in the #5 and #6 exhaust tube and therefore making adjustments based only on that cylinder. Sorry for confusion (mine)

Gotcha !!

Well, i got my anti sieze and my dielectric grease and now waiting on JonB's stuff to install and cross my fingers. I did notice as I pulled out the wires today from the distributor that #3 was corroded. Hope that was my problem.

Illl update as soon as I install and run it.

Since the car has been missing and what not and the computer has been compensating for this problem, after I install the new plugs and wires, will the computer need time to recoup and thus I will still have a misfire until it can reboot itself?

uvbnbit · Mar 19, 2012

Probably wouldn't be a bad idea to re-set PCM. Lots of thread discussion on that and it seems like certain years it didn't matter. Check with JonB on that too.

slitherv10 · Mar 21, 2012

uvbnbit said:
Probably wouldn't be a bad idea to re-set PCM. Lots of thread discussion on that and it seems like certain years it didn't matter. Check with JonB on that too.

Ill do that thanks for the reply

slitherv10 · Mar 27, 2012

Heeellpp !!! Update on missing and backfirefiring..not good

I just installed the new plugs and wires from JonB and still have a cold drivers side engine and missing on idle and backfiring on throttle. Thinking of just taking it to the dealer but not sure.

If it was a sensor, I would think the check engine light would come on. No?

Going to post this in the Grail section as well and see if anything subsides from there

Still can't figure out why the engine runs cold on the drivers side?

Any thoughts would be greatly appreciated

bluesrt · Mar 27, 2012

more than likely there is no fuel going in there, so no ball of hot fire, back fire? like i said maybe a lean pop. ohm out injectors- possible stuck injectors, maybe not. are the coils fireing that side? you need fuel, fire and compression. did it run good when you parked it? well iv seen injectors stick while sitting,rare,but it happens,i usually while the car is running,lightly tap on the injectors and i allways suceed in breaking them free.

Ratical2 · Mar 28, 2012

Slither, see the other post ....

The other thing is that you call call up The Wizard and he can talk you through most of this stuff.

Wezbad1 · Mar 28, 2012

Ive seen this before. I ended up changing the intake manifold gaskets (lean miss). Look for streaks running up the manifold, hard to see but look close. Change the thermostat while your at it.

slitherv10 · Mar 28, 2012

Wezbad1 said:
Ive seen this before. I ended up changing the intake manifold gaskets (lean miss). Look for streaks running up the manifold, hard to see but look close. Change the thermostat while your at it.

Streaks running up the manifold? Don't get it. What kind of streaks. What do you mean by streaks. Sorry

bluesrt · Mar 28, 2012

hey also check wireing for a mouse chewing the wires,they love the coating on the wires,didnt you say it ran perfect before you parked it

Wezbad1 · Mar 28, 2012

The streaks are little lines of carbon coming from the intake port running up the manifold. Ive been finding that #1-2-7-9-10 are ports where the gasket is starting to squeeze out. Take the valve covers off to see the ports easier. Make sure you check your fuel pressure also (at least 47psi)

slitherv10 · Mar 28, 2012

bluesrt said:
hey also check wireing for a mouse chewing the wires,they love the coating on the wires,didnt you say it ran perfect before you parked it

replaced all the wires and plugs to no avail.

Engine misses some backfiring

Enthusiast

Enthusiast

Enthusiast

VCA Venom Member

Enthusiast

Enthusiast

Enthusiast

Enthusiast

Enthusiast

Enthusiast

Enthusiast

Enthusiast

Enthusiast

Enthusiast

Enthusiast

Legacy/Supporting Vendor

Enthusiast

Enthusiast

Enthusiast

Enthusiast

Enthusiast

Enthusiast

Enthusiast

Enthusiast

Enthusiast

Viper Owner

Enthusiast

Enthusiast

Viper Owner

Enthusiast

Similar threads

Forum statistics

Share this page