[JFoxx488]

Hey, I have an odd problem. If this exact problem has been addressed before, please direct me towards the right thread. I've searched around, and haven't found anything that fits this exact problem.

I have a 2000 GS Auto, 100k miles, and the only mod is a short ram intake. I recently just changed my plugs and wires, and after pulling out the old ones, realized they were wayyy overdue. I went with Pulstar Plugs and NGK Wires. Well ever since I changed them out, I've been having an odd sputtering at low rpms. When I first start the car, it idles just fine at around 750, with no problems. The second I click into gear, the idle drops to around 600, but it feels like it's sputtering and the car shakes. Then if I let off the brake and push in the gas, it starts sputtering even worse, and shakes violently, but only for a couple seconds, and after I push in the gas harder and the RPMs rise, then it goes right back to normal. It will also sputter the same way after sitting at a stoplight for a while.

My initial thought was that it was misfiring, but then a mechanic friend of mine said that he thinks it's not getting enough gas. The coughing it does kinda is the same sputtering a car will do when it's running out of gas. I've also run out of gas a couple times in the last couple years, and run with the gas light on several times.

As of right now the car is driveable, and doesn't seem to be getting any worse gas mileage, which also makes no sense whatsoever. I'm not getting a SES light or any lights on the dash indicating any problems.

What does the problem sound like? Fuel pump, coil problem? What should I look for next?

 

[New2Mitsu]

If it started exactly when you changed the plugs and wires, i would bet on that. If you have your old set (Which i keep for a couple weeks for this exact problem) put them on and try it out. If its still happening, then its not your tune up.

If it is, then change 1 plug and 1 wire at a time until you get the bad idling, Then switch and swap the plug and leave the wire to determine if its the plug or the wire. Then return.

It could be the result of a bad plug or wire.

I'm going to assume you also unpluged and hooked one up at a time to not mix up 2 of the cylinders firing orders? Although i would think that would cause a rough idle too...

 

[TurtleTamer]

^^^Solid advice there.

I'd bet on one of the plugs' gap is off. Sometimes they can be bent to have less gap during shipping or maybe even from the short drop down the tube.

 

[JFoxx488]

I didn't know it was possible to mess up the firing order on the 4G64... they only have 1 way of correctly hooking up. Unless I'm retarded, which that very well may be. :dunno:

I just threw everything away, without thinking about it. But I can just head over to the shop and grab some copper plugs for like 10 bucks just to see. I have no idea how to gap plugs, as I've never seen it done. But I will definitely go through and check each.

I was also reminded by a friend of mine, that I just recently filled up my tank with gas, and that the sputtering started around the exact same time.

 

[New2Mitsu]

It is nearly impossible, lol. I have the 4g64 myself and i just changed my plugs and wires. Make sure that the wire to the coil is really attatched. And that each wire is pushed down so its flat with the head.

To check Gap, buy a tool. Should be real cheap at your local automotive or maybe even hardware store. The one I have measures down to 0.01mm. (Not sure what that is in inches. From what i recall the origional Mitsubishi Eclipse manual calls for 1.0-1.1mm, in the manual is says 0.039-0.043 inch. If you have an ohms meter you can test the resistance of each plug and wire. I can give you the values if you want.

As for the Gas, I would test out the plugs and wires first. All it may be is a simple slight off gap.

Goodluck

 

[Hendy]

^ follow this guys advice. Only thing to add is when you put the wires on plug you should hear them click into place. The gap tool is one of the best cheap investments ($1-2 max), the guys at your parts store should be able to easily explain and show you how to check and adjust gap.
It does sound like a gap issue but if that doesn't help, when was the last time the fuel filter was changed? Running it low and dry a lot will pick up a lot of trash out of the tank.

 

[TurtleTamer]

It was just after filling the tank you say? Did you over-fill it? It's theorhetically possible to have picked up some raw fuel in the evap lines. That'll make it sputter for sure when that non-atomized extra fuel gets sucked into the combustion chamber. It happened once to me. Now I just fill until it cuts off the first time. Fix ended up being just to drive it a little while to burn up that gas.

 

[JFoxx488]

Alright today I pulled all the plugs and re-gapped them. I ordered the plugs online, and the article said "Pre-gapped"... what a load of horseshit haha.
3 of the plugs were gapped to .020 and only one was at the correct .044. But I changed them, and everything got better, but now it's idling lower than usual, around ~450ish. It's not sputtering as much, but it still is sputtering. Should I just run my tank dry and refill at a different station and see if I still have the problem? Or is there anything else I could've messed up in the ignition?

As for gas, I filled up at the cheapest place I could find. Probably not the best choice, but I was nearly broke. What places are known for having the best pumps and the cleanest gas? I've heard BP and Sinclair are decent

 

[New2Mitsu]

Thats good. When regapping did you damage any of the cares? Did you gap them properly? Also, i would go over your wires and plugs, make sure there ALL tighten to the right torque and pushed in and down all the way.

Your ECU may also need adjusting to the now different firing sparks. Ie, more spark, so it may need to add more Air and Fuel at idle to compensate for the low spark there was before. When you had low spark it was probably pushing less fuel and air through the cylinders at idle so you wern't flooding the plugs/cylinders. It should only take 20 mins to 2 hours of driving before the ECU compenstates for the better spark. Otherwise you can reset the ECU but it'll reset all your settings. I would just drive it abit.

If that doesn't fix it, you could have a bad spark plug or wire. But if it improved greatly with the gap, i would bet on the ECU. And i still highly doubt that the gas is your issue. The gas station wouldn't be able to maintain constant customers if its gas was s***. Nobody would buy gas there.

Let us know how it goes and goodluck

 

[JFoxx488]

Alright, well I had a really difficult time leaving work yesterday. I work from 10pm-6am and I live in SD so it's quite cold at night. Well I started it, and it idled rough, then I went into gear, and it started sputtering really
Bad, so i pulled out onto the road while smashing the gas and it hit ~2500rpms and settled back to normal. But then I finally got a SES! Yay . So I went into autozone and they scanned me and apparently my #2 cylinder isn't firing. So I pulled the plugs and wires and we went inside and tested them, and they're good. So I just ordered 2 new ignition coils and they'll be here tomorrow. I'll update with info tomorrow on how everything goes.

 

[TurtleTamer]

LOL I don't now if I've ever heard someone so excited to have a check engine light.:lol: Glad you're getting somewhere.

 

[JFoxx488]

Alright, installed both of the new coils, and the SES went away... but nothing changed. It still sputters like crazy. I'm thinking it's the EGR valve. All cylinders are firing perfectly, and I'm pretty sure I'm getting fuel, and It ran seafoam 500 miles ago, and has another bottle in there right now. So I'm thinking it's the EGR valve. Wouldn't that make sense because it only happens when it's cold? When I'm on the highway or at a constant speed for a while, it works fantastically, but when I first start the car, or stay stopped at a light for a prolonged period of time, it sputters. Could an EGR valve being blocked up cause the exhaust gases to back up, and make the engine misfire? or backfire? Am I going the right way with this? It's really starting to piss me off :rant2:

 

[JFoxx488]

I win. I pulled my plugs out to check them, and they were all black and burnt looking. So I went to autozone, and got some OEM replacements (NGK Copper), and the car is running like a dream. PULSTAR plugs are bad buisness. (At least the Iridium ones) I ordered them pre-gapped, and they were gapped incorrectly, and even when they were installed correctly, they still caused violent misfire/backfire. When I took them out, ALL 4 were black/burnt, and obviously not working correctly. I installed the new plugs the exact same way, using all of the exact same wires and coils, and now the car runs great. Thanks for all your help guys, I don't know what I'd do without this forum :blush2:

 

[New2Mitsu]

Thats Great News! Well, dont blame the plugs, I would first blame the website. Sure its hard to damage a spark plug, but obviously something is fishy about the sellers. Why would a pre gapped plug be gapped wrong? And only one (if i remember right) dont they come in packages of two?

Lol, from what it sounds like, is you got a good deal on a pair of s*** plugs that more than likely were a defect from the manufactory or something. Lol. That or they truly were a bad name brand (not sure if that brand is good)

Anyways, GL with the copper plugs. Hope they work alright. I think i have NGK G-Power Platinums running at the moment (considered OE replacement.

Cheap fixes are always good ones.

 

[ryandiaz440]

glad you figured out your problem man. Now you know to use NGK coppers.