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2G What could I be missing? (running issues)

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Kod

10+ Year Contributor
289
0
Mar 29, 2011
Kingston, Pennsylvania
Well first here is everything that has been changed within the past 2 years (car has actually only driven maybe 12k?)

Spark plugs and wires (ngk single electrode remember seeing a post on that)
ISC motor, EGR Valve, and PCV valve from mitsu
02 Sensors changed 1 year ago and the MAF because old one was shot.
I just cleaned the intercooler out and still a SMIC hard piping from intercool to TB.
Biss screw and TB gasket use to have a boost leak but doesn't anymore.
BISS is exactly 2 full turns out and the throttle cable is adjusted correctly.
Fuel Filter replaced 1 year ago.
Sprayed starting fluid over areas I could reach with straw in and idle never went up so I am "assuming" if there is any leaks they are minor but still a leak regardless if there is any.

I do need to do another BLT but is there anything at all I could be missing because the car at times has power and at times doesn't. I do need to replace lifters with the revised ones because the ticking is straight annoying but I know that that has nothing to do with my issue.

It also has a here and there miss but not at all times..

The other day when it was on jack stands and in park I was revving it up slowly and it have like a little miss every 1500 rpm I went up but doesn't always do that.

Any help is appreciated.

Edit: I will try opening the ends up on the plug wires and I have some electrical cleaner I can spray the coils out with to make sure its clean.

I am pretty sure the gap is at 28.
 
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Why don't you do your BLT then ask questions?

what were the new plugs gapped at?

Another item not mentioned as part of maintenance would be the fuel filter.
 
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Cleaned the pack out because was dirty and opened the end of the wires a little bit so it has better contact and grab for seating, car is on jacks at the moment but seemed to start a little better.
 
Maybe a loose ground? Can you explain exactly by "sometimes it has power sometimes it doesn't" what happens when you don't have power? Say you're driving and hitting 4000 RPM, if you lose power does the RPM's drop? Or do you just feel the car not accelerate? If you take out your spark plugs right now what do they look like? (Are they wet, white, black, cracked)
 
Just not full power at times rpms don't drop or anything and plugs are normal wear no green tint to them and no sweet smell coming from exhaust so no head gasket issue.

I don't burn any oil I do know that for a fact.

Gap on plugs if I remember right is at 28 but should they be different for the little mods on this car?

Engine is bored 30 over, Injen intake and cat is hollowed out, not really looking to go mass performance since more work you start to put on it the more that will start breaking.

I have replaced the alternator a few times and someone did say that there is suppose to be a ground on the exhaust but I never found a wire for it, if so does anyone got any type of PDF file or JPEG of where all grounds should be on this car?

Edit: On a cold start it starts up fine and runs fine then for a few seconds acts like it wants to die out spits and sputters but never actually stalls, then is fine after that, just a bad boost leak or other possible issues?
 
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Do you have access to an oscilloscope? Just to see what readings you're getting from your O2 sensors. If your cat is hollow it will probably give bad readings, not 100% sure I don't remember exactly where the O2 sensors are. Basically what's the fuel/air ratio?
 
Going to do a BLT this weekend and will post back afterwards, going to do the soapy water method for bubbles since I found nothing with starting fluid when running.

Thanks for the input everyone has given so far. I am not a expert mechanic but am capable of most things besides tearing a motor apart. (just have never done it so who knows I possibly could)

I do have a cheap multi meter that I do know at least works because I used a good one of a friends on my old ISC motor and they both read the same, going to find out how to exactly test if I can even do it with that on the fuel pump to check readings.

Just another piece of info is that I have a stock turbo and it pushes 14 lbs of boost even with the old one that was in the car.

Edit: Well decided to lift back seats out and just turn the key over without cranking and I hear nothing from the back so guessing fuel pump is on it's way out or actually now thinking of it probably a bad MPI relay because that use to make a funny noise once in a while when trying to start the car and it wouldn't let it crank over at all just like a buzzing noise.
 
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Well this confused me, I decided to unplug the ISC motor before starting it, which made it idle higher but then kept dropping down.


This is at steady idle in park.

Steady 2100 - 2200 rpm then drop to 1100 then back and forth until I turned car off to plug it back in.

Should that act like that if unplugged?
 
Cold start, was running as normal with the random stutter for a few seconds after running then was fine, then started acting weird like that. I tested this ISC before I put it in last year and read good and BISS is 2 full turns out (ill check on this maybe it moved on its own a little..)
 
The original issue is intermittent lack of power.

If you can monitor the intake manifold pressure and that is consistent, that rules out several things.

If you have a wideband O2 gage then that would rule out several others.

I will assume that the car is not dead so running lean and/or sputtering from a boost leak is not the issue.

Stock lash adjusters, especially ticking ones, do not open the valves efficiently. They work off of oil pressure. This may cause problems when the car gets hot, the oil thins out, the car feels sluggish. Then randomly you punch the gas and the car feels great, for what ever reason. The increase in pressure holds the collapsed adjusters in a good position. This is why adjuster tick goes away momentarily when you rev the engine.
 
If lifter tick is excessive enough the knock sensor could pick up the noise and retard timing while you're WOT because the ECU thinks the engine's detonating. The only actual way of knowing what's going on is getting some kind of tuning software and capturing a log of the "loss of power" you're experiencing.

Always, always, always do BLT's. Sometimes I get lazy but I always TRY and do them with every oil change and 9/10 you'll find something. Wouldn't hurt to do a compression test either, just to get a baseline of motor health.
 
Well doing lifters soon, now since I see how they go in and out on this car and with the blue point tool for depressing the valve springs looks pretty easy to do.
 
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