Hey guys, I just replaced my fuel filter. I didn't get a Mazda one; I went to the import parts store right next to my work where I buy my spark plugs from. I got an Original Engine Management one... FF120 043-0889 if anyone knows the #s.

It revs fine, but at about 3K under 2/3rds-full WOT I get this chattering sound. I've read all the stories of detonation... and I was wondering, ****, am I getting detonation!?! I'm installing an A/F meter right now (came yesterday)... but I don't want to push it.

Any insights?

 

maybe you put it the wrong way if it had a direction?

 

Nope, I put it in the right way. There is an IN on the fuel tank side, and I verified it on the old filter.

 

I just put the old filter on, and it is happening still.

Okay, so I put on my A/F meter today, in the midst of this crisis. At idle and just cruising, it would be in the middle, and if I was crusing under 3K it would be there too. But any time I got into the gas, it would lean out bad, and I would hear the noise...

Did I bend a fuel line?

 

THAT IS DETONATION.

Okay, now that we've got that out of the way, make sure that you wired the thing up right. Have you checked your fuel pressure? Do so. Do you even know that the pump flows stock numbers? IIRC, the TII fuel pump is different from the N/A one - make sure you've got the correct unit!

And PLEASE don't get into boost.

Brandon

 

Er. I are dumb. Fuel FILTER not PUMP. D'oh.

Anyway, I'd check your line pressure and that it's not an N/A part.

Brandon

 

Yeah, I figured. I'm going to be treading very lightly. Well, I put on my old filter just for ***** and giggles and the same thing is happening. My A/F meter never goes into rich, it only stays in the middle and runs to lean when I give it a little gas. I could slowly bring it into high rpms without it leaning out.

 

btw, I took the intake off, and nothing seems messed up. or broken.

 

Check your injector plugs, your fuel pump wiring, and your fuel rail pressure.

Brandon

 

Thanks man, I will. Going to buy a pressure checker in the morning, and going to check the voltage at the pump.

 

Flush out the fuel lines. You may have gotten something in them during the filter swap and it is plugging the lines or one of the injectors. Check everything from the filter to the secondaries to make sure.

 

hmmmm....how can I flush them? I can believe that... but that is quite odd.

 

my vote would be the line got messed up when you put the filter on, like dirt in it, or bent too much..etc. OR when you installed the new filter you knocked a sensor wire loose, you might want to look all the wiring over. It wouldn't make sense for anything else to be causing it, the only thing you modified is that area of the car. Good luck.

 

Yeah, thats what I am afraid of =) I was very clean with installing the hoses, that is the weird part to me. I also pulled off the intake to see if I bent anything, and everything looked fine I'm going to get a pressure tester tomorrow. Does anyone know where to hook that up?

 

Take two readings - one before the fuel pump, and one after. Right in the area of the fp would be a good place

Brandon

 

filter

 

D'oh. Read what I mean, not what I say.

Brandon

 

The NA and TII fuel filters are the same.

 

Yeah, I noticed that on Mazdatrix. Where can I get a fuel pressure tester? I just went to Pep Boys and Autozone, they said the one they have wouldn't work, and they both had the same one.

 

Hey guys. I did the rewiring for my pump by the way of 1300cc.com. I was getting 7.5 volts at idle, yuck. Now I'm getting 9ish. I am still running extremely lean, except when crusing or idling. I am going to take apart the fuel system, but does anyone have a method to doing this?

 

Well, I hope someone has some advice for me. I took the intake off, pulled the injectors out, and they were in bad shape. I also had a bunch of white stuff in the secondaries, inside the screen. It kind of looked like teflon tape. I cleaned it all out, reassembled the fuel stuff, jumpered that yellow cable, and I didn't have any external leaks. All my injectors tested 12.7 ohms. I can get the RPMs up slow without leaning out, but once it leans out, bam..

I'm at a loss now. I have a fuel pump on the way, and I will probably replace all 4 injectors; they look like they were in bad shape; 2 of them had cracks.

Any advice would certainly be appreciated!!!

 

*ahem* Check your fuel pressure!!!

IMO, you've got some sort of blockage somewhere in your fuel lines. Some pressure testing would tell you where it is.

Brandon

 

try checking your fuel pump voltage under load. make sure it goes up to 12-14 and doesn't stay at 9.

 

Hey guys, I bought a fuel pressure tester at NAPA today, and hooked it up at the engine inlet. I had 40 PSI constantly, idle, driving, and it wouldn't budge. I couldn't put too much load on it or it would lean out. I had it plugged in right above where the fuel enters the engine by the spark plugs.

Yesterday I took off the fuel rails and took off the injectors, so unless there is something jammed in the foot or so of line from the inlet to the primary fuel rail, it must be something else? I'm going to check the stuff out tomorrow (at the rail.)

 

The pressure sounds about right (can someone verify that, please?) - that means it's either a fuel injector problem or an ignition problem.

Here's what I'd do:

- Check your spark plug wires (make sure they're going to the right places).
- Check your injector wiring
- Check your pressure sensor
- Have your injectors cleaned/flowed

Brandon