RonniEdwards

iTrader: (1)

I've checked them and didnt see anything but friday i have an appt to hook up to a vac pres test and smoke machine, plus fuel pressure check.

MastrShake2129

Update on my issue, driving down the highway, push clutch all the way in, car drops to 500 rpm then stalls, (with ac on and off), tried it again throwing it right into neutral, same result drops to 500 holds for a bit then stalls. Going to try in the morning throwing it in neutral but keep my foot on the gas and slowly bring down the RPM instead of letting it drop from 4k. if that keeps it from stalling, I am thinking O2 sensor. Still gonna go out and clean MAF sensor. will give an update tomorrow.

andrewhelmus

Could be a neutral switch..

Check this thread: https://www.rx8club.com/series-i-tro...switch-133529/

RonniEdwards

iTrader: (1)

have you disconnected your battery recently?

andrewhelmus

It was bad gas..

I can't believe it. What are the chances of that? I mean.. I've gotten bad gas before, but I seriously can't believe the horrible timing for such a thing.

I just filled up.. calculated my gas mileage: I got 11.2 mpg on the first tank after replacing the front O2 sensor. Mind you this is far worse than before.

But after filling up with fresh gas (at a different station).. I immediately noticed an increase of power, and also happened to notice that my idle is smooth and doesn't fluctuate. Also feel smoother through the revs.

I've only gone 11 miles so far, but my best guess is that my last fill up was **** gas.

I'm going to throw some techron in the tank on the next fill up.

MastrShake2129

Last time I disconnected the battery was over a month ago when I did the radiator swap.

Neutral switch, or the clutch pedal switch? If its the neutral switch, how much of a pain is it to get to?

Tried to get the car to stall out on the way to work and on the way back, could not get it do die on the freeway. So I was unable to test the effect of slowly lowering the RPMs. However I did stall out after driving like 2 miles before getting to the highway, pushing the clutch in going like 40, then again when stopping at the light on the same road, that one I was at a stop and had to re-crank.

I am going to clean out the MAF sensor this weekend, and if there's an O2 sensor in stock at autozone or advance I'll swap that out, so if its fixed I will never know what the problem was lol

RonniEdwards

iTrader: (1)

you can get a front O2 sensor from Amazon for 166. just in case:


On another note. my intermitten power seems to not exist when the car is at 165F or less.

andrewhelmus

Hey guys.. I haven't updated because I haven't really had chance to diagnose further..

I just ordered an oem fuel pump motor from BHR..

I figure this weekend I'll replace that and clean the sock and hopefully see some good results.

The more I've researched on here.. the more I found that my fuel pump could be the issue. Especially the part where this whole thing is intermittent. I couldn't help but to notice that when I fill up a full tank of gas, the problem seems to go away for a while, leading me to believe that my fuel pump is overheating and on it's way out. I also learned how common fuel pump failures are on the S1's.

I'm also going to dig into the intake this weekend. I figure I should test all of the actuators and valves to make sure that they are functioning properly. I came across Jon316G's thread about testing the intake valves. His video was very informative, and taught me a lot more about the intake system, than I had previously understood.

I'll keep you guys updated!

MastrShake2129

Update:
Was not able to get the car to stall out when I want it to, but on 7/31/13 my engine started to mis-fire pretty badly. Towed it home, de-flooded it, and got it to run again, smooth until the car got half warmed up then started to misfire again.

Tested the coils with a cheap wire (5.99) and plug (1.98). I got sparks on both "Leading" position coils (Coils 1 and 3 when looking from the driver side Left to Right), and no spark from both "Trailing" positions (Coils 2 and 4 when looking from the driver side Left to Right). Replaced all 4 coils, and tested the old ones on an Ohm meter, the 2 that didn't spark failed, the other 2 were ok (so I've kept those 2 as spares).

Car is up and running again, On the first drive to work (8/5/13), the RMP's still dropped to 500 approaching a light while stopping. Then no issues the rest of the 30 miles to work. On the way home (also 8/5/13), had a similar issue this time it dropped below 500 threw on the battery light, before catching and going back to 1k, then back to below 500 then stabilized at 800ish. Was going to test the neutral sensor behind the clutch by pressing the clutch a few times next time it did it, to see if I could get the sensor to unstick, but had no issues to and from work 8/6/13, or this morning. Next time I have news I will update again.

andrewhelmus

So last night I pull the fuel pump. Finally!

I was a little disappointed to see that the sock was fairly clean.. because I was really thinking that it was going to be filthy. And that would have been a great indication of the cause of some of my issues..



I cleaned it a bit anyways, as there was a tiny bit of debris inside of it. Then I threw in the new pump motor I got from BHR. Thanks Charles!!

Tossed the pump assembly back in, and I took it for a spin. It certainly felt more stable/consistent. Didn't do much for my idle, but I didn't really expect it too. But the power felt like it was all there. Haven't driven it enough to be able to tell for sure, since my problem is intermittent, and it could have just been working fine at the moment.

So next I decided to rip apart the upper intake manifold..

I've never dug into this before on this car.. so I hopped on here real quick to find a simple DIY. I have it apart in a few minutes. If you haven't done this.. don't be intimidated, it's fairly simple.

The first thing I noticed was this:



This is the connector for the VDI solenoid. And as you can see.. that exposed wire should be plugged into the connector.

Now.. I won't lie. It's certainly possible that I was too rough in taking off the UIM, and I caused this issue right then and there.. but I was pretty careful.

In addition to this.. I also found that the vacuum hose that leads to the VDI solenoid was disconnected, and also that I couldn't seem to find it!!

After a bit of searching though, I found it dangling way down below. I would have normally also assumed that I could have also caused the vacuum hose to disconnect in removing the UIM, but the way this hose was hiding, it didn't appear that I forced it to fall off.

I was pretty happy at this point because it explained almost everything!

I fixed the connector, and hooked up the vacuum hose, and made sure everything was tight, and then I put it all back together.

When I took it for a spin, I paid close attention to the 7250RPM area, as my understanding is that this is when the VDI opens. I could be because I was really looking for it and paying extra close attention, but I could hear/feel a slight difference. I could tell it was there. But it was kind of subtle.

I never really noticed it before, but then again I wasn't looking for it before.

Everything felt great otherwise.. No loss of power.. pulled strong.. everything was great! Idle still slightly rough, however, but nothing too bad. And until I get a stock intake, or an AEM one, I'm not going to complain about the idle.

Since I reset the ecu, I'm going to give it a few days before jumping to conclusion, and let it relearn the fuel trims, etc.. That will also give me time to see if the problem comes back or if it stays at bay..

I'll keep you guys posted..

drifted88

Thanks for the update Andrew. Thanks for being the guinea pig on the fuel pump

andrewhelmus

No problem.. I just wish I had better info. At least for me, even if the fuel pump doesn't/didn't solve the problem, it's still a preventative maintenance kind of thing. I just hit 84k miles, so the pump was probably bound to fail sooner or later.

DoubleRR8!

ok.. so i am completely new to rx8s.. and rotaries lol buti just traded my 00 R6 for this 04 RX8..witch i got running after the guy couldnt figure out what was wrong with it...anyways i got it running..and it started up fine and idles good (cel is on because of the exhaust set up he had) headers with 3inch exhaust..race beat was the brand.. anyways im going for a test drive now and wen i give it gas..it spudders and then goes, sometimes i give it gas and just DIES, i have read everything and keep coming to a different conclusion, anyone care to help me? oh! this guy did use the rx8 for auto X and did mention he removed alot of "performance" parts..soo anyone care to direct me please!

DoubleRR8!

oh he did mention he put alot of the OEM parts back to replace the ones he took off, maybe coil packs? vaccum leak? it is late here in texas so woking out side was just crappy so i couldnt really give the engine bay a good look.....

andrewhelmus

My first place too look would be the coils, wires and plugs. Ignition is key with these motors. A healthy ignition system will surely help your engine last much longer.

Are you getting any other CEL codes? Is the CEL blinking when it sputters?

I would also check all the vacuum lines and make sure there are no leaks. This thread will help you with that:
https://www.rx8club.com/series-i-tec...iagram-214910/

The solenoids will be a bit tricky to get to, as you have to remove the upper intake manifold, but that's not a hard job as long as you have basic hand tools. I would definitely check all the lines!

Also, you said that the previous owner had aftermarket parts installed, that he removed. Did he have an intake? If so, make sure the VFAD is capped below the throttle body.

Tell us more about the car.. how many miles, transmission, etc..

DoubleRR8!

The car has 77k miles its the 6port 6spd. I am not sure of all the performance be had on the rx8. I am not 100% sure if the cel light was blinking, I was to exited to just teat drive the car around the block a few times. Lol but on another note I tried hooking up my scan tool and it didn't pick up anything..as in it didn't even connect. There's no power going to it. Cig fuse? I did catch the gas leak everyone is complaining about. I fixed that. Um.. Like I said im not 100% on everything he took off. But I just don't want to buy something that really isn't going to fix it. Lol

DoubleRR8!

I did notice the fresh air tube had some cracks on it..but I don't think it goes all the way through but I will change that as a process of elimination.

shadycrew31

iTrader: (6)

I'm confused whos car is having issues at this point? It looks like 4 guys keep posting in here with completely different issues.

DoubleRR8!

I'm sorry, I tried posting a new trend in my issue but the forum wouldn't let me..my rx8 has similar symptoms as mentioned on this tread..

DoubleRR8!

Also Andrew..i got in contact with the previous owner. He said the coils and wires are new..so I am wondering if the plugs got fouled out if he deflooded it.(if it was) ....also said he deleted the cat..and shoots fire ***** wen redlined and shift..think O2 is burned out?

shadycrew31

iTrader: (6)

Have you guys considered searching the internet instead of circle jerking for 3 pages?

I wasn't born with the knowledge I have now, I searched, took stuff apart, broke stuff, repaired it, etc.

DoubleRR8!

You..know what? That's a fantastic idea. O wait..i did that already and mentioned in on the above description I put. I like to do things right the first time..not break stuff and fix it. As some one who has seen error first hand..there just shouldn't be any room for it. But thanks for your help.

shadycrew31

iTrader: (6)

Its a 10 year old rotary powered car, bolts are gonna break, clips are gonna snap.

Do all the basic tests first then move on to the more complicated stuff.

Compression test is the first thing I would do before dropping $300-400 on maintenance items.

BigCajun

iTrader: (1)

You know what?
If I just bought a car I knew little about, and someone took the time to respond to a question I had, I don't think I would be a smart-a** in replying to them.

DoubleRR8!

Not being a smart ***..being honest. I know about cars. I have 3 ASEs and not scared to ask for help..he did not reply with a "helping answer". I have spent 4years over seas, so wen someone asks me for help I don't think twice about helping. Like I said. No room for error ever. Everyone else had a helping answer or question. I assume you have never heard of "the only stupid question is the one not asked"...think twice before butting in a conversion you have nothing to do with..i am not a horrible person but I like to be honest.