Hey guys, I apparently have had an account made here for a few years but usually just use the forum for information and keeping up with new things. I must say this is a great resource for alot of info for these cars and I appreciate everything I have learned about the 420a from here.

Onto the problem:
Vehicle - '97 Eclipse GS, Auto, 236,xxx miles, 100% stock down to the factory Stero, used 90 miles highway driving 5 days a week
Problem - was running a bit rough randomly at idle the last few days, but perfectly smooth when given throttle or driving down the road. Yesterday hickuped at 60mph driving down the road but nothing afterwards on that trip. After filling with fuel (ethanol, but usually use reagular) and making 2 stops we began the return home trip, the car began to misfire violently and was difficult to keep running at a stop and required both pedals to negotiate the stop lights while in town. Once out on the highway the car would begin missing randomly and might smooth out if I eased off the throttle slightly.

What ive tried - First removed spark plug wires in an attempt to find the dead cylinder, number 4 first caused the engine to stall, restarted then found 3, then 2 also caused a severe drop in rpm, number 1 did not change a thing. Suspected number 1 injector problem. Tapped on injector and idle seemed to smooth out. Today I Ohmed the harness from the PCM connectors to each injector, to the coil, between all the injector plugs and the coil connections. All appears within spec and no shorts opens or problems while pulling and moving the harness all over.

Replaced with known good parts - All 4 Injectors, Coil, Plug Wires, New Plugs, and PCM.

What Else ive checked, compression 180-180-180-185. Vacuum gauge installed 21inhg at idle. Pulled plug wires again when missing at idle, each cylinder seems to have the same effect now. Pumped 5 gallons of the fuel out into pickle jars and looking for watter or dirt separation as i speak. Blocked the EGR tube off with a penny and now the car will idle all day long smooth as can be but may or may not run smoothly with a load on it.

I have not checked to make sure the timing belt hasnt jumped yet, my air compressor isnt working and I know what its like trying to take that crank pulley off without an impact, forget it. So my question for you guys is to throw any more ideas at me cuz this one is making me beat my head against the wall.

BTW no codes stored since the EGR blockoff but have not driven it very far. Previously it had codes for injector drivers and coil drivers and random misfires but that was probably from me pulling injector plugs and spark plug wires before the 30 mile drive home.

Thanks in advance guys, I knew the day would come with this car wher something would die and not be worth fixing but I was sure it would be the transmission before anything else.

'97 Dodge Avenger
'94 Eale Talon AWD
'91 Saab 9000

Update, drove the car to work, or more like limped it to work. Sprayed brake clean at the intake gasket top and bottom, no change in rpm or signs of leakage. Unplugged O2 sensor to see if forcing a rich condition would help anything, no change whatsoever. Got a P0301 cylinder 1 misfire code now, on top of the O2 sensor code but that is obviously from me unplugging it. I pulled the timing side of the engine apart and lined up the marks, timing belt looks excellent and the marks lined up every time I spun it over. I did have another thought on the way home, im going to change the crank sensor tomorrow, the way its acting I cant make myself believe that its going to solve it but im grabbing straws here.

'97 Dodge Avenger
'94 Eale Talon AWD
'91 Saab 9000

Since you have a multi meter, check every sensor you can get to. The ones that are in reason of course. Tps, iac, even coolant temp sensor on thermostat housing. Bad coolant temp sensor can cause this. Happened to me. Could barely drive it. Only way I knew was my obd 2 scan gauge was reading whacked out coolant temps bouncing all over the place. $16 later, ran like new. Let us know

Thank you very much for taking the time to reply. Yesterday I got upset and started replacing sensors 1 by 1 to eliminate them. So far it has a "known good" crank position sensor, cam position sensor, Intake air temp sensor, Manifold absolute pressure sensor, and coolant temp sensor (the two wire one on the thermostat housing, I think the other one is just for the gauge right?) the only thing I noticed odd was that there was alot of oil in the plug for the old crank position sensor but I sprayed it out with lectramotive cleaner and blew it out before I plugged the other one in. Also the wires on the coolant temp sensor are only still connected by about 3 strands each, none the less they still read 0 ohms when I probed the wire about 4 inches back and stuck the other end in the pin socket.

Yesterday while I was speaking with the local snapon dealer about genaric obdII scanners, it occurred to me that my brother works for a Toyota dealer that used to be Toyota and Chrysler, so I asked him if there was any chance I could use the DRB scan tool (hells yes they still have it and he told me to stop by on saturday after hours and we will take a look at it.

'97 Dodge Avenger
'94 Eale Talon AWD
'91 Saab 9000

Erik P.
Official 2GNT thread Hijacker
Some say that he's driven over more Covenant than he's shot, and that his grenades aren't where you'd expect them to be...
All we know is, He's not The Stig... But he is The Stig's Spartan cousin!

haha no no you are thinking e85, i meant ethanol as in e10 which is available as the mid grade fuel around where we live (89 octane) as opposed to regular unleaded (87 octane) which contains no ethanol most places. Its been my experience that the non ethanol fuel is cheaper per mile to run which is very important to someone that commutes 44 miles each way 5 days a week.

The reason I brought it up was that alchohol fuel tends to cleanse ones fuel system and possibley knock some garbage loose in the tank that could be stuck in the fuel filter. Also if you take a car that has not run ethanol fuel recently at put a full tank of it in the engine does tend to run very strangely until the computer picks up the slack of needing more fuel because of the reasons you mentioned of alchohol taking more to achieve the same stoichiometric effiency.

'97 Dodge Avenger
'94 Eale Talon AWD
'91 Saab 9000

I can't say for 100% certainty for your area, but it's generally nationwide that ALL gasoline regardless of the octane rating is ethanol blended e10 because of the emissions. Saying that you run ethanol is generally going to mean that you're running e85.

That aside, with all the problems you're having I would still lean towards the fuel. If nothing else was changed other than the fuel then you might have a tank of bad gas. Have you run through the entire tank yet? If not I would still see about pumping it out and throwing a little fresh fuel in with an ECU reset.

Erik P.
Official 2GNT thread Hijacker
Some say that he's driven over more Covenant than he's shot, and that his grenades aren't where you'd expect them to be...
All we know is, He's not The Stig... But he is The Stig's Spartan cousin!

The pumps around here are labled ethanol if they contain ethanol and not if they dont . I did pump 6 gallons out on sunday and went up and filled the car back up with regular, that made no change at all then and still hasnt. The gas I put in the pickle jars does not look like it has water in it at all, so I actually used it and the other 4 gallons in the car my wife is driving instead of her eclipse and that car is running just fine also. I dunno i'll keep looking for it.

'97 Dodge Avenger
'94 Eale Talon AWD
'91 Saab 9000

Well an update as of the last few days, I have still not figured it out but have tried a few more things.

Smoke tested the intake manifold, unable to produce any results since eventually the smoke comes out the oil cap and the pcv hose and ends up everywhere but in the few seconds before it did that nothing was comeing from where it shouldn't. Pulled injectors out again and checked the spray pattern of this set and they look very nice, while they were out I stuck the boroscope down the ports again and could not see anything obstructing the spray pattern. Hooked the car up to the DRBIII yesterday and found out just what the PCM is thinking, Which is nothing short of logical, 190 - 202 degree coolant temps, 80 degree intake temps and the MAP is within 1 in hg of the mechanical boost gauge that I put in it to monitor, O2 sensor is bouncing around which is good and the fuel trims are not far out of whack at all which I was very surpised and kind of dissapointed to see, I would have thought that it was running lean since I do not smell any fuel when it starts missing. I put a fuel pressure gauge on and ducktaped it to the windshield for the drive home, It is not fluid filled so it jitters some but never went below 50psi and sat around 55 mostly. So the computer is not finding anything wrong with its inputs and the fuel pressure is not dropping out when it starts missing which I was hoping to see. That leads me back to the outputs, which means tearing into the harness since the coil, wires, and injectors are all from a running car.

'97 Dodge Avenger
'94 Eale Talon AWD
'91 Saab 9000