Engine issues. plz help!

IggDawg · #1 07-14-2005, 09:45 AM

Ok, here;s the dilly...

Among the other gremlins my current SVX has, one of the more recent ones is a nasty engine issue. since a week ago or so, every so often the engine would sputter and hesitate when I'd try to start it. it would rumble and choke, maybe stall. I'd fire it up again and give it a little gas. after a few tries it would start up and operate normally.

Yesterday on the way home, the engine started hesitating and losing all its power while driving. All the sudden I had nothing, and once I shifted into neutral the engine died. I tried several times to start it, but it would never run smooth or even hold its own RPMs. I'd give it gas once I'd start it... the revs would raise quickly and the engine would run very rough. if I let the revs fall, they would not go back above 2000 RPMs no matter how much throttle I would give it. Then as if by magic, it hiccup'd and ran again just fine after about 10 minutes. got a few miles down the road... complete power cut. this time I had it towed... it wouldnt; run normally again

This morning I got a fuel filter, figuring I'd do the obvious first. maybe crap was gumming everything up. after I replaced it, it behaved the same way as it did yesterday. sputtering, not going above 2000 RPMs, dying if I let off the throttle. then it after about 3 tries it just kinda ran as if by magic. I chalked up the sputtering to the filter being full of air. I drove around the parking lot a bit and it felt 100% normal. I get onto the road, accelerate to 40 or so... complete power cut. 10 minutes of trying to start it, and I manage to get it running again and I drive back home. did the same thing again a little bit later... seemed to be running ok (since gremlins ALWAYS magically disappear never to be heard from again). drive a little ways down the road and BAM... no power. get it running again, drive it back home and turn it off. start it back up again after a few minuites, and it idles rough but clears after some gas.

I think it's an electrical problem. it goes from 100% fine to "doesn;t run" or vice versa in moments. there also seem to be a few grades of "Doesn;t run". there;s a moderately rough grade where I can get it to hold 2000 RPMs, but stall if I let off. there;s a rougher mode where it coughs up to 1000 or so after ignition, then coughs back down and stalls out. if the problem was in the fuel system or with the MAF, I feel like there would be grades of suck between "runs perfectly" and "doesn;t run"

I'm going to try the plugs, but I'd like to know if there's any way to check if a coil is bad using a multitester or something. Also, any insight as to the nature of the problem from past experience would be greatly appreciated. Basically I need to sort out this issue by this weekend or I'll be looking at new cars over the weekend. sick of car issues. but if I can get it to run again, I can at least continue to work and pull through till I get the transmission and cooling system repaired.

Yoda3000 · #2 07-14-2005, 10:26 AM

Hmm, I'm not well versed in such issues, but I would say it's definitely not something like spark plugs or fuel filters. Those problems wouldn't be intermitent. It most likely is something electrical, possibly a sensor going bad. I don't know many of the sensors, but I do know your car will run like crap and die if the Mass Airflow Sensor (MAF) is not working, maybe that's going bad.

<shrug> that's the extent of my engine knowledge, good luck.

--Mike

Earthworm · #3 07-14-2005, 11:14 AM

Possibly MAF or Crank/Cam sensors

Beav · #4 07-14-2005, 03:24 PM

...or loose/corroded grounds.

immortal_suby · #5 07-14-2005, 07:42 PM

I agree - check the MAF or wires connecting to it.
I had identical symptoms when mine took a dirt nap.

IggDawg · #6 07-15-2005, 03:02 AM

Ironically I had discounted the MAF... reason being that when I unplugged it and tried to start it, the symptoms stayed exactly the same. I guess it should have been my queue that if I unplug it and everything stays the same that it WAS the problem. I'll try playing with the wires. is there any way to figure out if the filament itself is bad? also, I have a spare legacy/impreza MAF... I assume that won't do the trick, will it...

thanks for the help guys!