Odd power loss. Fuel issue?

SuperK · Post by **SuperK** » April 6th, 2007, 6:49 am

last month I did the following:
Tune up (Oil+stabalizer, Spark plugs/wires, fluids)
New Cat, 02 sensor

I also run CAI for what that's worth. Anyways, she's been running very well until recently. After the new cat and 02, I started putting in that injector cleaner for a couple weeks with every fill-up, no problems.
However, I took a 1.5k mile round trip the end of march, and my check engine light started turning on. Nothing seemed wrong, I simply turned off the car and back on, and the light would stay off for a few hours then pop back on.

halfway through the trip I had some major hesitation issues. step on the gas and what? I'm supposed to go? I primed the pedal and it worked fine.

Now the light stays off, but now, randomly at accelleration, it's starting to hesitate again, goes reeeeaaaal slow until I hit 4k RPM. Something catches, and it gets full power.

I'm thinking its a fuel issue. You think something is clogged? Where should I start? I couldn't find the darned fuel filter... is it located with the pump, because... I kind of stripped a screw trying to look under there... oops.

Bumpysbro · Post by **Bumpysbro** » April 6th, 2007, 8:14 am

there are two fuel filters, one right next to the heater hoses on the firewall right behind your intake manifold and the second is attached to the fuel pump. could be lots of things causing it. i would either say the disty is on its way out or maybe a egr sticking open.

SuperK · Post by **SuperK** » April 6th, 2007, 9:34 am

are you aware if the 93 SOHC disty is the same as the 94/95? I accidentaly bought one of those a while back...

OROutdoors · Post by **OROutdoors** » April 6th, 2007, 12:03 pm

It sound like you did some good maintenance. Did you also recently clean the CAI filter? I have a K&N filter in my Mazda3, once when I cleaned it, I must have done something wrong, because the fuel economy and power tanked immediately thereafter. I'm not sure how this problem was caused -- maybe too much or too little oil, maybe not allowing the cleaning solution to penetrate long enough, or didn't use enough... but there definately seemed to be a direct correlation to the filter cleaning and the fuel economy.

SuperK · Post by **SuperK** » April 6th, 2007, 2:20 pm

my filter is new, and I did check it, that's definitely not the problem.
I went ahead and changed the fuel filter up front this morning, as well as replaced the cap on my distributor. Definitely helped... when I drained the fuel in the old filter, came out brown. Like, a healthy poo brown. I don't think it should be that color? Autozone didn't list the second filter, the one on the pump. anyone know what kind of filter is on there? I'd like to replace that filter while I'm at it.

I hope nothing serious is wrong with my MX-3. She my baby.

SuperK · Post by **SuperK** » April 6th, 2007, 8:17 pm

mmm... Update...

Idle went south now. She'll stall sometimes, or idle real rough... something "clicks" from time to time and the rev's jump up, then she idles smoothly... till I open the throttle.

There is still massive sluggishness on accelleration. Sometimes I can "correct" the issue by releasing the throttle then applying gas. If it doesn't work the first time, usually the 2nd or 3rd time does it. I'm leaning towards the EGR being faulty? Any input would be nice

twoie · Post by **twoie** » April 6th, 2007, 9:00 pm

I have a GS and was having similar problems. It gradually got so bad that I could'nt get it up to highway speeds without a struggle. Fuel economy went into the toilet. I did the HEI mod with the coil and all seems to be working normal.

I wouldn't think it would be a lack of fuel ( clogged filter ) because as you demand more fuel ( over 4,000 ) you get a response.

Hope this helps

twoie

SuperK · Post by **SuperK** » April 9th, 2007, 5:27 am

can you give me a basic rundown of how much that hei mod was to install? I'm replacing the cheap parts first, like the egr, but if that doesn't fix it, I'll be forced to do something with the disty.

jaydog5678 · Post by **jaydog5678** » April 9th, 2007, 10:24 pm

There is no need to replace the fuel pump strainer unless you but rocks and sand in your gas tank.. That's just my opinion.

EGR valves have been known to go bad on the 1.6 DOHC. The symptoms are pointing me in the direction of a poor flowing or clogged EGR. You mentioned you had a check engine light come on. I wondered why no one mentioned checking that out first. I would find out what code the computer has stored before going any further. Don't disconnect the battery for any reason! If you need help pulling codes, you need to jump the 10 and ground in the diagnostic box with a jumper wire, with the key in the on position. Refer to the shop manual for the code, counting the number of blinks the light comes on.

SuperK · Post by **SuperK** » April 10th, 2007, 5:58 am

the check engine light only turns on when I drive for about 8-10 miles under 3.5K RPM. If I run her harder, light doesn't come on. But after the light comes on, all I have to do is idle for a minute and it flips off. Meh? I'll have to check the codes.

SuperK · Post by **SuperK** » April 24th, 2007, 5:32 am

OK so I didn't want to post a solution until I was positive, but I did get this fixed. It was my brand new O2 sensor. I pulled the codes and was very disappointed. I got a cheap aftermarket brand for 45. meh. I went with the Denso which was 77 bucks, got it in yesterday, and it fixed everything.

Don't buy cheap O2 sensors. Chug out teh extra cash.
Especially stay away from the "replacement" brand.

...meh. Money.