95 protege work going on

[William35453]

#1 -- 1995 protege dx 1.5: idles rough, runs way too rich, and at a constant speed (any speed!), it will lurch and buck but as soon as either accelerate or decelerate, smooths out. only at any constant speed does it do this violent lurching. i've cleaned EGR, throttle body, had injectors ultrasonic cleaned, changed air and fuel filter, and still does it. maybe MAF sensor? any ideas appreciated.

#2 -- did compression test yesterday, just to satisfy myself, and was 180 on all four cylinders. also put in new spark plugs. still got the problem.

been reading in the archives of several mazda forums and some say cleaning the EGR isn't enough, that you have to remove the throttle body and clean throughly the ports to the EGR. any thoughts on that? i did run a drill bit by hand into the ports to pull out any carbon, but do i have to remove the throttle body for more thorough cleaning?

oh,and plug wire are only 4K miles old from former owner.

#3 -- OK, today obtained a used MAF sensor from salvage yard and cleaned with genuine MAF cleaner. It immediately fixed the problem. idled smooth, shifted smooth, drove like a new car and where before was blowing black smoke, now doesn't smoke at all . . . for a couple hours. I was elated and then on way home, felt a tiny drop in power, check engine light came on and now won't idle at stop at all when *under load*. Will idle fine and smooth until put in gear or until AC turned on, then becomes erratic and stalls out. But still no excess smoke at exhaust.

HELP!

 

[RABID_MP5]

you gotta get the code dumped on the check engine light and go from there.

 

[William35453]

code dump

thanks so much for the reply! i've also posted on two other mazda forum and over 100 people have "viewed" and not one single reply. apparently this is the forum where members actually care to respond, even if only to cheer on the work.

I "thought" I'd dumped the code by removing neg battery terminal and stepping on brake light for 15 seconds to discharge system. When i cranked up then, the 'check engine' light had gone off and car drove wonderfully for several hours at all speed and on interstate at 80 mph. This a.m. i repeated this procedure twice more and also had read in some forum archives that the vacuum purge solenoid for the EGR can stick open and give a direct but invisible permanent vacuum leak, so i tapped on it with a screwdriver handle and car cranked up and ran fine the 12 miles back into town (fingers crossed). So. . . . did I reset the code by repeatedly discharging and cranking, or might it actually be the purge solenoid? I've read that after discharging, car must be cranked 4-5 times and driven 30 miles or so to reset the ECM. Is that right? Is there a correct way to dump the code? Thanks again for your response so quickly.

 

[sanblaster]

You should try clubprotege or imazda, bigger 2nd gen section, and also this thread is in the wrong section. Probably why so little response man.


2nd gen section here: http://www.mazdas247.com/forum/forumdisplay.php?f=143

 

[RABID_MP5]

I really meant you need to get a OBD2 code reader, hook it up under the dash, and read the contents of the ECU error code (i.e. whenever the check engine light is on). Then look up the meaning of the code.

 

[William35453]

@Rabid, I've not seen a code reader that will read earlier than 1996. can you steer me to one? i've gone to autozone, etc and they also can't read earlier than 1996.

 

[RABID_MP5]

good point. My 626 was a '96. Not sure if it might be OBD2 in 95? You could at least see if the connector under the dash looks the same as newer cars. And research it. It might be OBD1. Some current readers can do that I think. You could always ask the dealer, who I'm sure can read it (for a price...)