College Student First Car Build

You may have a bad Cam Position Sensor.

I could see it causing your problems.
I don't think the ECU would mistakingly throw that code.
Check your wiring and make sure the engine hasn't rubbed through the casing somewhere.
Check your sensor for debris.

You didn't mean to say code P0304 did you ??




Your vacuum leak may also cause your problems while your car struggled to deal with unmetered air.

(unless it's just some weird noise your car's making.)

Both of those problems are listed as causes for engine speed fluctuation.

Unfortunately no, it was a P0340. I checked the cam position sensor and made sure everything looked fine and reset the light and it has yet to come back.
I hear the loud whistling at around 2k-3500 rpm when accelerating, and I assume it is a vacuum leak. I'm going to look into it more but I've driven with the leak for a while with no issues and I have no clue when they were replaced last

A new Cam Sensor isn't cheap but you guys pay about 3/4 of this price.



Check yours for broken or pinched wires and check the connector.
Make sure it's installed properly.

Throwing a P0340 code might be good news because a new sensor may fix your problem. (except that they're kind of expensive)

They're cheap on eBay.
It might take more than a month to get it though.

If you need a cam position sensor lmk. I have a few in my shop Ill send ya cheap

Gabe710 said:

I hear the loud whistling at around 2k-3500 rpm when accelerating,...

Click to expand...

Can you post an audio clip of the sound ??
It may help us.

I got the plugs and wires in and it definitely feels way better. But the P0340 code has returned. I pulled the cam position sensor out and it has this weird black work down spot on it. So it is getting replaced

I did find it on car parts for $25. I have to see how much shipping is, but I will keep that in mind dp. Thanks both of you!

As for the video, I'll have to grab it later cause I'm going out and not taking the Mazda.

TL;DR located at the bottom
This car is starting to frustrate me and of course the car has become undrivable due to the random drops of a few hundred rpm and it'll randomly turn off during idle sometimes. What better time than the day school starts, i can't find the key to the truck, and it is entirely too hot to ride the motorcycle and still be able to be in a hot classroom?
A few updates though:
Sunday I replaced the spark plugs (manually gapped them), ignition coils, and wires, reset the CEL and the car felt like it ran 1000x better. Didn't drive it until yesterday morning to work and the car felt worse than before.
So I got some money to get a cam position sensor and got my girlfriend to grab it from autozone and drop it off at school while I was in class. I get out of class and attempt to replace it in the school parking lot, I pull the old one out to compare and notice the magnetic cylinder on the end was a different size. Autozone's website said it was a direct replacement for the fs-de so I figured maybe it was an updated part or something. Screw it in and try to put on the connector and it won't snap into place. so I threw in the old one and limped the car to the same autozone where the cashier tried to argue with me. Asking me what car, I told him and only the protege came up and he didn't listen when I told him as long as it is the So again (this time with the engine piping hot) i remove the sensor yet again to show the clerk. he compares them and yet again says they're the same part.So at this point I get pissed and tell him it won't fit in the car and he replies it is the same part. So i told him it won't fit, why would I lie. So he goes outside and tries to shove the connector on and whaddya know, it didn't fit so at this point I'm pissed from him trying to force s*** on that obviously doesn't fit and I couldn't even return it cause the card to buy it and the receipt was with her at the house. So again I grab the car and limp it the 25 minutes home and try to make it to another closer autozone to exchange it or to check to see if I had gotten the wrong part. Go to the one close to my house and find out the box was listed as a CRANK position sensor (looked like the cam however), but they didn't have it in stock. So found yet another one that was 20 minutes away that had one in stock. (it was 9:30 at this point and they close at 10). So I drive out there and they have it mislabeled or something.
(I just checked the site again and they have the cam sensor for the 626 listed as a complete different price, part number, and everything)
So I went this morning to a pick n pull and grabbed one from a 626 which got rid of the P0340 but it is still misfiring just as bad and even more undrivable.


TL;DR
I have replaced the intake tube, spark plugs, wires, coils, and the cam position sensor and the car still barely runs. I am lost at this point. The tech I know said clean the throttle body so I will tomorrow before class

Two things-is the MAF directed the correct way for air flow?

If it is, unplug the MaF and see how it drives- if its better its the maf. If its the same or worse its not the maf

Dpwhitehead1 said:

Two things-is the MAF directed the correct way for air flow?

If it is, unplug the MaF and see how it drives- if it*s better it*s the maf. If it*s the same or worse it*s not the maf

Click to expand...

I unplugged it just now and it wouldn't start until the 3rd try (would turn on and immediately off). But it seemed to run worse. as for the orientation, I have no clue. This is how it is (ignore the battery corrosion, haven't made time to clean it and whatnot and those don't fit well, but when your car won't start and you're stuck in the parking lot with only those you make do)

Other possibilities are a dirty IAC and a dirty EGR.

EGR'S are a known problem with our car. Some guys have to remove and clean it every year.
They get dirty and stick open or closed stalling the car.

It doesn't always throw a code because the ECU thinks it's working.

A dirty IAC mostly affects idle but can have an effect at higher rpms if it's stuck open or closed.

pcb said:

Other possibilities are a dirty IAC and a dirty EGR.

EGR'S are a known problem with our car. Some guys have to remove and clean it every year.
They get dirty and stick open or closed stalling the car.

It doesn't always throw a code because the ECU thinks it's working.

Click to expand...

I found a thread earlier about the IAC and it said to unplug it with the car running, if it stalls it is good, if not it is bad. As soon as I wiggled it loose it stalled.
I will do some research on how to get the EGR out and cleaned and attempt to do it tomorrow morning

I assume to clean it use brake clean or carb clean and a toothbrush?

Yea that's right.

The EGR is a bit tricky to get to and remove and you apparently need a 1/4" drive stubby ratchet handle.

The IAC (and I think the EGR) have screws that look like Phillips but they are JIS (Japanese Industrial Standard)

The heads of the screws like to strip and the proper screwdriver or bit can make all the different.

I remember one guy saying that he left his car in gear and pushed it (I forget whether it was forward or back) then hit the pbrakes then blocked the wheels.
This rolled the engine in the engine bay a bit which gave him a few more mm of clearance to reach in there to remove the EGR.
I'm pretty sure you have to reach in there blind to get the bolts out.

are the JIS heads needed to remove the EGR from the electronic part or from the car? I found a post that says they're 12mm bolts and then there's "phillips" head screws holding the actual EGR to the electronic portion
https://www.mazdas247.com/forum/sho...o-EGR-Removal-and-Cleaning-for-Rough-Idle-Fix

The screwdriver is to disassemble the EGR once it's removed from the car. Same with the IAC.

Chances are those screws are seized and you'll strip the heads with a regular Philips screwdriver... A lot of guys have.

ah, just the reassuring thing I need to hear.
From the looks of it, I think I actually have a JIS screwdriver. I'm gonna give it a go without trying to strip it. If so I'll see if I can get one in the morning. Unfortunately, I have to do it at 10 PM tonight cause of work and class (cabpatch)

I just read through part of that thread and it talked about a rough idle..
I was thinking a sticking EGR could cause problems at any RPM, I still think I remember guys having issues at rpms other than idle.

Keep in mind this may not fix your problem but for some it's regular maintenance... And it's cheap to do.