Kev's JDM 1997 Protege

[GavGav]

My stock z5 5mt does this occasionally and it rumbles noticeably when I come to a stop. I've never actually stalled though.

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[irishkev90]

Good to know someone else has the same experience. Thanks.

Well now I'm confused on what the clutch safety switch is. There's a gray switch at the "top" of the pedal with two small wires (black and brown/black stripe) and a white switch at the "bottom" of the pedal with two larger wires (black/blue stripe and black/red stripe). According to the wire colors in the Haynes manual, the gray switch would be the starter interlock switch (safety switch). That doesn't make sense to me because the little pedal travel required to activate this switch is nowhere near the travel required to disengage the clutch to start the car while the transmission is in gear. This leads me to believe it might be a cruise control cancel switch (kind of like the brake pedal switch) to shut off cruise control when the clutch pedal is depressed.

Using similar logic, the white switch at the bottom of the pedal should be the interlock switch considering the pedal must be fully depressed to activate the switch therefore ensuring the clutch is disengaged so the engine can safely be started while in gear. Whoever put the alarm system in (Viper 550HF) cut the lines for this white switch to use with the system (assuming for the remote start feature).

Instead of messing with the alarm system wiring, I think I'm just going to splice the wires for the white switch into the wires for the neutral safety switch on the transmission. This should send the signal to the ecu that the clutch pedal is depressed while the transmission is in gear without messing with the signal from the neutral switch when the transmission is in neutral. It should also keep the safety factor with the remote start system so that it doesn't start while in gear.

Mostly just thinking out loud here. It helps to write down my thoughts and ideas sometimes before actually going through with it. Not really looking for approval or acceptance of the approach. Just like with my intermediate shaft bracket.

[FE3-323]

odd question... but what alternator do you have in there??? amperage?

[irishkev90]

No idea. Should be the stock alternator. 70 amps? I've been thinking about upgrading.

How do you think the alternator is connected to this?

[Protege_Driver]

Welp you might look into using the idle air bypass (and it goes by some other names too) to fix that idle dropping down low just as you idle. It's the screw in that post that sticks out from the top TB.


I can provide more info upon request.

[irishkev90]

I've adjusted the idle with the screw, but doesn't seem to help much. The edu will randomly throw a code for the idle control valve, as well. I swapped the throttle body with the one from my '98 that isn't showing any codes or idle problems. Didn't help. The idle still bounces and the revs still dip to almost stalling occasionally. Starting to think it might be the ecu.

I also have some left over transmission fluid I'm going to dump in tomorrow to see if that helps with some noises I'm hearing. And I need to find where that suspension clunk is coming from.

This is the opposite of fun.

[FE3-323]

i've noticed with all of my cars, a higher amp alternator drastically helps the idle as well as overall

[irishkev90]

Hm, didn't think that would have an effect on idle. What's a common upgrade? And would the pulley need to be swapped?

[dtorment]

I actually have the same problem with my '97 protege DX right now; while idling at a stop light, the RPMs drop down significantly and the car almost stalls, then the RPMs go back up to normal just as fast. This issue manifests itself especially when the AC is on. I also get a P0505 code intermittently. I already swapped the ECU, cleaned the Idle Air Control valve, checked for continuity from the IAC valve to the ECU, cleaned the MAF sensor and the car still does the same thing. I also ended up swapping the IAC valve and still nothing. I noticed there was a tear on the Air Intake Hose between the MAF sensor and the Throttle Body a couple of days ago; So I fixed the hole and the code hasn't come back. Before, after clearing the code with a scanner, it would come back on just by driving once around the block. I now suspect the MAF sensor could be intermittent or about to fail since i replaced/checked everything else. The car still idles weird tho, even though the code hasn't. Hope this helps your troubleshooting, looking forward to hearing if you found a solution since that might help me too

[MazdaNoob]

AC is a huge HP parasite at idle and it cycles on and off. the IAC is designed to accommodate this to an extent by raising the idle when it senses the AC has cycled on . there is also a pressure sensor ( 1 wire) on the PS pump that tells the ecu to open the IAC as well

[irishkev90]

Well, the a/c hasn't been included with this originally, but now that it's recharged, yes, it does affect idle. Already knew that.

Someone also said that the upper clutch pedal switch (the gray one) has an affect on the idle speed. So maybe once my fsm gets here and I can figure out what wires go to what ecu pins, the idle will settle down.

And this just came to me, but it could also be the egr valve. So I'll take a look at that and clean it out like I did with my '98 since that had the same problems and the valve was just dirty and getting stuck in the open or closed position.

I'll be driving my dad's car for the next couple days because he wants me to check out some wheel problems he's having. That'll give my car enough downtime to be torn apart for more than a couple hours at a time.

Oh, and for some reason the a/c fan isn't kicking on. Need to look into that, as well.

[Kitty]

Rewire your **** to factory before you change anything else out.
And make sure the signal from the trans neutral switch is actually reaching the ECU proper.

The EGR is a **** on the BHA, cleaning it out was a 30k interval on my car until I did away with it.

I wouldn't try upgrading the alt in the BHA. It's got a really weird voltage regulator system that is half dependent on the ecu and half on the alternator. I ended up swapping to BG series alternator with an internal regulator to solve a intermittent charging problem.

Don't run the AC until you get the condenser fan working as it will burden the system more than necessary.

[irishkev90]

Yeah, I'm waiting on a '97 FSM to show up before continuing with the wiring situation. In the meantime I've got my dad's car to figure out a problem with and to continue looking for the source of a suspension clunk in the front left of my car.

[irishkev90]

Got the a/c fan figured out. Apparently there's two different circuits depending on the transmission. For an automatic, both relays are wired to separate ecu pins while the manual has the fan relay tied into the compressor relay and then into one ecu pin.

Also kind of reduced the suspension clunk, but haven't quite gotten rid of it. I accidentally pressed the front lca bushing too far into the arm which was pulling the arm forward slightly. Pulled it back out a bit to match the other side (which is completely quite) and it helped, but I can still hear it over certain bumps. Usually while the wheel is turned.

New ball joints, new lca bushings (front and back), new end links, new sway bar bushings. For both sides.

Only thing I can think of now is that the left rear lca bushing needed to be forced into alignment with the bolt holes. I'm wondering if that bushing was bad from the beginning or maybe the control arm got bent somehow and it's putting too much stress on that one bushing.

I can't recreate the sound in the driveway as it only happens over sharp bumps, usually when turning.


On a completely different note, I'm thinking about getting the new Miata Club model. I need to get rid of the '98 and might trade this in, as wel, if it's worth it. I doubt I'll find someone around here that'll appreciate this car and not destroy it.

[Kitty]

The BG fans are wired in a similar but different fashion for atx vs mtx. On the atx there is a temp sensor in the rad that can cut of the ac compressor as well as turn either both the fans on or the main rad fan higher if the engine reaches a certain temp.

The mtx just has the horrible 1 wire fan switch the breaks when you look at it.