Stumbling on accellaration, darn.

[AquariumPerson]

Hey, I have a 1990 mitsubishi eclipse GS 5 speed manual and I just got a new clutch in it but i dont think that would affect the problem... What is happening is sometimes when I put it in first and push on the gas it stumbles, or SLOWLY accelarates untill it gets up to 2500 or so then accelerates like normal. I dont get it, I just got new spark plugs and a fuel filter too. My car was sitting for 2 years before I got it, I rescued it like, July of 05' from sitting by the woods...I thought new plugs and a fuel filter would fix this problem but I just dont know. Mabe there is water or something in the gas tank somehow?!? I just dont know...

ALso, earlier today i had it in neutral and was revving it up and listening to the engine and it stumbled almost every time, one time it stumbled, while i had the gas pedal depressed, for around 4 seconds before revving up like normal. ANd, 2 or 3 times while it was stumbling there was this "pop" sound that i could hear and feel, NOT a backfire, while it was stumbling, it only happened once not like, repeditly popping or whatever. Just once then it started to accellarate like normal. ofcourse after a few seconds it started to accellarate like normal. This is really bothering me im 16 and this is my first car i got it free and just put $400 into it for the clutch, plugs, and fuel filter. I just dont know what it could be. please help, thanks

 

[1990telawd]

and make sure your intercooler pipes didnt get knocked loose. if yours leaking your loasing hp and your going to stumble

 

[Purevil]

and make sure your intercooler pipes didnt get knocked loose. if yours leaking your loasing hp and your going to stumble

Um... its a gs, he doesn't have to worry about his intercooler pipes leaking. but he's got the right idea. Try removing the rubber hose between the maf and the throttle body and check it for cracks, especially around the ridges. My old 92' esi used to do the exact same thing, I traced the leak back to this pipe. After I replaced the pipe it never happened again. Good luck.

 

[sm0kinjuana]

I would check the cas just make sure the wires that run out of the bottom arnt broken. and also go over the firing order.

 

[AquariumPerson]

so purevil are you talking about the big rubber hose connecting the "air filter" to the "intake" just to make sure we are clear im not soo sure about all these technical things. ANd if there is even the slighest leak it could cause a problem? And, what is the CAS?

Also, i read somewhere that i could have a vaccum leak out of the BISS screw area? Is that true? thanks much

 

[AquariumPerson]

also, it doesnt seem to have as much power as when I got it... i guess this could be the problem, a vaccum leak?It used to pull me back in the seat and now its just bleh sorta...

 

[9!'clipseDOHC]

I had a very similar problem with my gs. I thought it was fuel related and I was so focused on thinking that it was the fuel filter of the pressure regulater and it turns out that is was just my spark plug wires. I had the same symptoms, stumbling under acceleration, lack of power, etc. I was running a set of universal 8mm Accel wires. When I replaced the wires with a set of factory 7mm NGK wires all my problems went away. Check your wires and make sure there aren't any cracks or burn spots. Also if they look really old and worn go ahead and replace them with the ngks. You should also ckeck and/or replace all of your vaccum lines because they tend to get very hard and break and cause all sorts of problems.

 

[AquariumPerson]

well i still do have the ORIGINAL spark plug wires i beleive, you think replacing them would help? I will probably do that, and check my vaccum lines too

 

[AquariumPerson]

well i checked over the vaccum lines, no leaks or cracks it seemed. I dunno if this is realevant or not, but when im holding the fuel line that comes off of the fuel filter, and pull the cable that gets pulled back when you push the gas pedal, dunno what its called, but anyhow, if i pull that cable real fast while holding the fuel line, it seems like there is a "fuel cut" or something, u know what i mean? I dunno if it just feels that way because the fuel is moving thru the line faster or what, but it feels that way, then thats the time that it stumbles right after i pull that cable back and as the fuel seems to not be flowing thru the line as quickly, which makes me think of the fuel pump...or the spark plug wires, heck. When i get them push in interior fasteners from machv motorsports i might as well buy a pair of spark plug wires too. And if that doesnt work.......well i dunno. I sorta hate my car at times....

 

[9!'clipseDOHC]

And if that doesnt work.......well i dunno. I sorta my car at times....

That is the nature of the DSM beast. It is a love/hate retlationship. I know I have d my car and gotten so frusterated and so has almost everybody else who has ever owned or worked on a dsm. But at the end of the week day/week/month whenever you get it fixed and running "right" you love it and you learn alot (at least I do). Don't give up. My dsm was my first car and I spent 4 months working on it befor I even got it running. I would go ahead and replace your spark plug wires. You can't go wrong with a new set of NGKs. Even if they don't fix the problem at hand they will fix or prevent other problems. I don't know about the fuel pump, but I would wait and try the wires first because they are cheaper and alot easier to replace. Keep me posted on your progress.

 

[DSMLoverFromUA]

I think you should check the plug wires. If that does not help check for vacum leak. If not check the coil pack. If the car have set for a long time you might have some water in the gas tank. Check everything that cost cheap to replace. When my car was hesitating under accel it was ignition related(plugs and wires). Another reason could be a clought exhaust. So check and tell us what fixed it.

Good Luck