Post was last edited on May 13, 2009 05:05. This post has been edited 1
times.
roger1918
+1y
It's a reman by Holly. I got it from a vendor on ebay. Warranty may be a bit hard to pursue.
But it's good to have something to go after. I'll pull the carb and check out the solonoid. I have parts off the old carb if I need them.
BTW, I bought the reman because the mechanic at Mazda said mine was FUBAR.
Post was last edited on May 13, 2009 05:05. This post has been edited 1
times.
roger1918
+1y
Hello MT,
I opened the carb and pulled the mixture solonoid out. Like you said, the leads are spliced so maybe it's new. It looks new.
I energized it about 200 times with it in its normal vertical orientation and it moved every time - no sticking observed. I put suction on the opening at the end and it opens and closes making a good seal. The inside of the carb is very clean. If it was stuck it seems free now. The O-ring seemed to be installed properly.
Is there anything else you want me to test/do with the carb before I put it back together? I will probably check the float stops. The fuel level was in the middle of the window when I checked it idle last week.
I pulled the ECU ground wires off the manifold and cleaned everything. I also flowed a little solder over the ends of wires where they extend beyond the crimps to ensure a good connection to the washer. I of course checked the resistance of the leads and connections to the meter and allowed for that. Measuring from the manifold to the ECU connectors I see about 0.1 ohm on the ground wire at each connector. That's about as close as I can measure with this meter. The resistance from the negative battery terminal to the engine is zero ohms.
Edit: I also checked all the solonoids on the carb. I can see that they all operate properly. I let some air flow into the chamber where the mixture solonoid goes and verified that the internal passages to a transfer port to the slow fuel cut solonoid and to a nearby jet are open.
Post was last edited on May 13, 2009 05:05. This post has been edited 1
times.
roger1918
+1y
The jet on the secondary side is an 85. Again clean. The hole in the bottom is right at 0.032". There are two sets of through holes in the side of this jet that are again about 0.025".
Edit: I blew some air in each of these jet cavities and it came through their respective jets, so the passages are clear.
roger1918
+1y
Since everything looked pretty good I put the carb back together (the bottom screw was quite loose - maybe a half turn. I found that it was also loose by about the same amount on my old carb).
I warmed the engine up and, with the mixture solonoid and O2 sensor disconnected, I activated the solonoid directly with 12 volts. Got the following at idle:
Solonoid not activated: O2=0.8v; rpm=800
Solonoid activated: O2=0.1v; rpm=650
I had to turn the mixture screw in about a quarter turn to get these results. With it at 3.25 out I wasn't getting much change (~0.1v) on the O2 sensor.
So the mixture solonoid seems to be working properly. Next thing is to determine if it is getting 12v from the ECU and if the ECU is switching the ground side properly. I have to go out for a while so I won't be able to do this right away.
I also received the EGR valve from hocbj23, but haven't installed it yet. Don't want to change too many things at one time.
Post was last edited on May 13, 2009 05:05. This post has been edited 1
times.
Post was last edited on May 13, 2009 05:05. This post has been edited 1
times.
roger1918
+1y
Well, there is a step forward here. It ran in closed loop for 10 or fifteen minutes without it going into fail safe mode. I had to screw the mixture out maybe 3/4 turn to get the dwell up from the low teens to mid 40's. I guess something got fixed by taking the carb apart.
Reving the motor brought the dwell way down and then it would work its way back up to the mid 40's. I kept expecting to see it jump to 27 degrees but it never did.
With regard to what has been changed: (1) the first test failure a year ago produced almost the same numbers as the most recent test. It passes everything except NOX at the 15 mph test, which is done at around 1900 rpm. (2) Since the first failure I have replaced the carb (a rebuilt for around $200 as I recall), the ECU (got that for about $25 on ebay), the O2 sensor (twice @ about $30 each), the #1 ACV valve ($50 from Mazda) and the vacuum advance ($35) as well as cleaning out the gummed up distributor. I think that's about it.
As far as what was replaced just before the last test, it was the 2nd O2 sensor, the ACV valve and the vacuum advance.
California doesn't offer a waiver on e-check. I think if you spend a certain amount of money and it isn't fixed, then they will give you $500 for the vehicle and junk it. However, you have to do this within something like 6 months of the first failed test and that time has passed for me.
In looking at past test results I noticed that 3 years ago - the last test it passed - both the 15 and 25 mph tests were done at almost 3000 rpm. Maybe that's why it passed. They may have changed the protocol. I've got to ask the test guy about that.