[94_RX-7 & 98_SC_400]

My mother has been complaning that her car (1996 Intrepid 3.3) just doesn't have as much go as it used to. Soooo...dad and I replaced the plugs and wires as an easy starting point. Crank it up, it runs like hell. OOOPS...forgot to reconnect the TPS, O2 sensor, MAP & air intake temp sensor that I unplugged to get to the #5 plug & route the plug wires. Plugged all that in, now it runs. But it idles slightly rough, backfires if you open the throttle too fast, and there is an occasional miss. I think OK...maybe the computer is pissed off because we ran it with half the engine bay disconnected, so I disconnect the battery, step on the brake, and leave it disconnected for a few minutes. Start it back up, same thing. Maybe a new part is bad, so we start swapping out old with new to isolate the problem. No love. Put all the old stuff back on there. Still runs crappy. I checked the computer for codes, and only got 12, which is "Battery has been disconnected within last 50 key-on cycles". Dug around the engine bay for vaccum leaks or anything of the sort, couldn't find anything. Without being able to see what's going on inside the computer, I'm at a loss as to what to try next.

 

[Starscream]

Are you absolutely sure you have your plugs gapped properly? and did you replace the wires as well as the plugs?

 

[94_RX-7 & 98_SC_400]

Yes. The plugs were gapped correctly, .050 inches. The wires were replaced as well. Moreover, when everything was put back the way it was before we started (old plugs and wires), it still did it.

 

[Si]

Big long shot, Crank position sensor, did you somehow unplug that? Secondly cleaned out youre Throttle body? Didnt have any crap on the spark plugs did you?

Lastly, TPS Sensor... take that off and the motor goes wacko.

Si

 

[1mz-fe]

i'd clean the cam position sensor and crank position sensor, and run a tank of fuel system treatment. if it don't fix it then you wasted an hour and $5 but the car probably needed it anyway.

 

[p3]

j/w, but why did you take all that stuff off in the first place? I just changed my plugs and wires today and all i had to take off was the airbox and the "accordian" tube that goes the the TB.

 

[94_RX-7 & 98_SC_400]

Originally posted by pimped3point3:
j/w, but why did you take all that stuff off in the first place? I just changed my plugs and wires today and all i had to take off was the airbox and the "accordian" tube that goes the the TB.

It seemed easier to me to disconnect and push that harness out of the way than to wrestle off the airbox and accordion.

 

[Starscream]

I just re-gapped all of my plugs to .050 and it seems kinda rougher than before, but I had a shitty gapper before and most of the plugs had different gaps. the haynes manual said .048 to .053 so I picked .050

What do most of you guys use for a gap?

 

[SPOOK R/T]

Unplug your battery for 10 min or more to clear the computer, any thing less well not work. How many miles on her? Sounds like it could be a pluged up Fuel filter. That will make the car have no power and run rough.

 

[94_RX-7 & 98_SC_400]

I got it fixed. It was something really dumb. My dad changed out the spark plug wires, and got two of them backwards at the coil. DOH! I was operating under the assumption that he could do *that* right. I guess not.

10 minutes is more than enough to clear the computer. I had to reset it again tonite, and I just disconnected it, stepped on the brake pedal, and reconnected it, and that was enough time to do it.

Thanks to all who helped.

 

[p3]

Originally posted by Starscream:
I just re-gapped all of my plugs to .050 and it seems kinda rougher than before, but I had a shitty gapper before and most of the plugs had different gaps. the haynes manual said .048 to .053 so I picked .050

What do most of you guys use for a gap?

I have mine gapped at .050, same as you

 

[BobVila]

If you get the spark plug wires mixed up you can really **** things up and it's horrible for the engine. Always double check everyhtingf before you start it up after checking the park plug wires.

-BobVila

 

[babyalex27]

.50 sparkplug gap??
What types of plugs were everybody using here and were they only on 3.3's ?????

I just did a MAJOR overhaul of new plugs/wires. I put in regular Autolites and I had to gap them at .35. This is a huge difference compared to .50.

 

[MoparPerformance]

I had a similar problem with my 95' but it just didn't seem to run right. I cleaned the all the conenctors under the hood and it actually seemed to run better.


I apologize if some of this was already gone over.... Are you using Champion Platinum/Copper plugs? Don't buy them from a dealer cause they'll rip you off. Go to an Autoparts store. I have experienced and even heard of problems with using other types of plugs. Check all the hoses, make sure there are no cracks or wear, make sure the plugs are properly gapped at .50. Make sure they are tightened properly. I would also replace the Spark Plug wires. I would use Mopar wires as to my personal preference or just use Autolite. First make sure your battery terminals and connectors are in good condition. Unhook the negative battery cable for at least 15 minutes and let it sit to reset the PCM Adaptive Learn Routine or while you are installing the new plugs. These are just the simplist things I'd do before going further.

Also, if not already done check the Oil just to be sure.... Inspect the Air Filter and if it's not clean, replace it. A Fram filter is a comporable and much cheaper replacement as to OEM Mopar.

Have you replaced the PCV valve? You can get a fairly cheap Fram or Purilator PCV Valve. It just goes in at the back of the engine. Also I'd repalce the Fuel Filter. I'm not sure how many miles or when if this other stuff has been done but these are the easiest and cheapist suggestions. Some of these things corrected certain problems with my 95' 3.3L.

Just use the process of elimination, always starting with the easiest things although sometimes not seeming to be related.

Just realized you fixed it, sorry, but here's my post anyway!

It's a little late but I do my plugs one at a time so there's less potential contamination that could get in the plug holes and so the wires don't get crossed. I guess I just assumed that the wires weren't crossed but yeah that'l do it.

Glad you fixed it!

Good Luck!
MoparPerformance

[ January 11, 2002: Message edited by: MoparPerformance ]

 

[1mz-fe]

there's no reason to reset the PCM after changing the sparkplugs.

 

[MoparPerformance]

Yeah, you should. I prefer to do it after tuning up, it will help the sytem adjust smoother and will also reset the TCM (Transmission Control Module).

I'm used to second gen in which it may be a little more important, but I'd do it with a first gen as well for optimal results. It's a very easy thing to do, there's nothing potentially adverse about doing it, the dealers do it to reset the Fuel Mixture settings to factory defaults and they usually charge about $50.00 for it or include it in one of those high priced service packages.

Although yeah, it's not completely necessary, it's best to do it.

Take Care guys!
MoparPerformance