Is there a sure fire way to know if my engine is misfiring?

[Timbers]

I have a feeling my TA is misfiring. I get some shaking going on at low RPMS, and if I am going about 60MPH in 6th gear and I floor it, it doesn't bog smoothly, it bogs and the shifter shakes pretty bad, and I can almost hear the engine missing.

The problem is I don't know if it is missing, because I really can't tell, I have nothing to compare it to. I have the Autotap system, which can detect misfires but is that an accurate way to tell?

Is there any way that I can for sure know if a cylinder is missing, besides just using my ears?

Thanks!

...Tim

[Jeff_in_Atl]

Can you put some info about what kind of car you are asking about. Is it a 1969 T/A or a 2002?

[Timbers]

Hey

Its a 1997 Trans Am 52K miles. Moroso Blue Max wires, Bosch platnum plugs.

The missing seems to be getting worse. I have my plug wires like triple heat sheilded and everything.

I am starting to wonder if the Opti is taking a crap or what?

Problem is I don't know enough to tell if the car is actually not firing properly, or if its just meant to run rough! I can't tell, I have nothing to compare it to! hah

...Tim

[Jeff_in_Atl]

This may sound dumb but it just bit me in the behind. Did you use the metal shields that were on the spark plug boots on the stock wires with the Moroso ones? If you did, take them off.

[Jay 02 TA ws6]

Is there a way to know if your engine is missing?
























Pop the hood.

[Injuneer]

If the PCM is detecting the misfire, the SES light should be blinking. AutoTap (enhanced parameters version or whatever they call it, not the basic version) can show you the misfire count by cylinder. Should be accurate, since you don't appear to have swapped in a big cam.

[Squat13]

Here is an easy way to check if its missing and which Plug if not firing. Get an old fashion Timing light, and connect it to each plug wire, one at a time with the motor running. If the light dosent flash on one of the wires, thats that plug thats not firing. You also could pull of the plugs and I bet one will reak of Gasoline (Or be covered in carbon to where it wouldnt fire). What type of plug do you run, because I bet its a fouled plug.

[Timbers]

Hey

I am running Bosch Platinum plugs. If one is fouled up, replacing it will only last so long until it gets fouled up again right?

Is it possible for a cylinder to misfire only under certain RPM? It seems low RPM makes the engine chug, but higher RPMS the thing screams pretty good.

I will definatly try the timing light trick..

Yes I removed all of the metal sheilds when I replaced the plugs and wires with some new stuff.

Thanks for all the help!

...Tim

[Squat13]

I am running Bosch Platinum plugs. If one is fouled up, replacing it will only last so long until it gets fouled up again right?

Is it possible for a cylinder to misfire only under certain RPM? It seems low RPM makes the engine chug, but higher RPMS the thing screams pretty good.

I will definatly try the timing light trick..

Yes I removed all of the metal sheilds when I replaced the plugs and wires with some new stuff.

Thanks for all the help!

...Tim

Man those Plugs are your problem. The Bosh Platinums are know to foul (especally the 2's and 4's) and to detinate (my spelling sucks). I would replace them with some Delcos first thing. I had a fuel foul on one when I was breaking in My old LT1 and it would run grat above 2000 RPM but Idled like a sick coon. I pulled all the plugs and slaped some AC delco's in, the thing sang.

I think it has somthing to do with the AC delcos being the stock plugs for that motor (the plugs were made for the motor, not just the plug hole's dimenisons). I will bet 50 bucks you just fouled out one of those Germany peices of crap.

[Timbers]

Ok

Well this winter I will definatly spend some time replacing the plugs for the 100th time! hahah

I never really liked the Bosch plugs because the center electrode is like pin sized. The diamter on that wire has to be about 5 thousanths if that! I never really liked that too much.

Anyone else want to offer a second opinion? What he is saying sounds good, low RPMS really suck, but high RPMS seem to be ok. I bet the reason for that is it is just spinning so fast you don't notice the missing as much.

...Tim

[Z Ya Later]

Ya know, that sounds like what the Z was/is doing. Its going to sound dumb, but check your EGR. How is idle? Is it fine at ~2000 rpm and up? To check it, just push on the diaphragm with your finger. Mine was stuck and that's what I think was doing it. Maybe that will help. Does it do it all the time or only when cold? Also, if you're getting new plugs, go with the NGK TR-55 plug in whatever material you like. I've got Irridiums sitting and to be put on. They were pricey, but they'll be worth it. Hope this helps.

[Timbers]

Hey

My EGR was in fact shot yes so I did replace it but that was a few years ago.

As for idling it idles fine, but if im coasting along in 2nd gear going in rush hour you can feel the car surging. Also, go 50MPH and put it in 6th gear, then floor the gas. In the past it would bog, but bog smoothly. Now it bogs but shakes pretty good. Thats another trick I use to see how smooth my engine is running.

I will look into the NGK plugs, I heard those were good plugs years ago when I was talking on this forum a lot.

Thanks,

...Tim

[Z Ya Later]

How does she perform from about 2000 rpm to redline?

[Timbers]

Fine

Its fine 2000 to redline, except sometimes you will get some surging around 5200 or so? hahah Probably all related to plugs or the opti huh!

...Tim