InfiniFC

iTrader: (8)

Hi all,

While driving on the freeway, my car suddenly lost power (as if I took my foot off the pedal). I was doing 70 when it started happening, and I had to put the pedal down (WOT) to try and make my way off the freeway. With the pedal all the way down, the throttle response would come on and off. Once I made my way to the shoulder, I got off the throttle and it was idling fine. No CEL, but the TPMS light was on. I am able to rev the engine smoothly past 7k RPMs. I Shut down the engine and pop the hood to take a peek. Nothing out of order, tire pressure on all tires look fine. Fire up the engine normally, again its able to rev. Since the TPMS light was on, I disabled DSC and drove off thinking it might think I'm losing traction..

It drove normally for about 5 minutes then started to happen again. This time around I could barely go 20mph. I pull over shut it down for a bit. After making a few phone calls I decide to try and make it home. Thinking a sensor is acting up despite no CEL, I reset the KAM and make my way home.

Oddly enough, it drove normally the entire way home which was about 30 min.

I've read similar issues from other folks but my case seems ackward especially with no CEL codes. Unless the TPMS sensor can put the car into limp mode?

Any one have an idea of what could've happened or recommend what I should check aside from making sure my tire pressures are okay.

My car is an 04 6-spd. Only engine mods are exhaust and CAI. My plugs were just replaced a couple of weeks ago.

Sorry for the long story... Thanks in advance!

expo1

TPMS has zero effect on the performance of the engine. It could be a clogged CAT or plug wires loose. When was the last time the coils were replaced?

Mazurfer

Echo was Expo1 says. I'll bet a loose plug wire on perhaps the front rotor.
Gotta make sure they are on tight, they should snap into place.
Plug wires could also be old.
Oh...and what's your mileage, it could be time to replace coils.
Hopefully it's not the cat.

Check the tire pressure.........while it seems odd, the two issues are not related.

InfiniFC

iTrader: (8)

Thanks for responding expo1.

I was initially thinking the same thing about the TPMS, thank you for clarifying that.

I picked up the car used last year, so I don't know if they were ever replaced. When I had the car at the dealer for service, I asked the guy to check to see what has been done to the car. Only things that showed up were PCM flashes and recalls. Its something that's on my list of things to do when the budget allows.

I had a clogged CAT in my old FC (hence my User ID) and the symptoms were different then what I experienced. The engine wouldn't rev above a certain RPM and hold power on my FC. Last night it felt like the electronic throttle was cutting out under load. Also when I pulled over and revved the engine, it was revving freely to redline. I'm not disagreeing with your diagnosis, just comparing the differences with a previous experience. I'm planning on getting a midpipe (high flow cat) as well.

I haven't checked the plugs/wires yet, but will look today. I didn't think about the plug wires, though I did have the plugs recently changed.

Seeing that the car was able to drive normally afterwards, would it behoove me to replace the coils first?

InfiniFC

iTrader: (8)

The car has 47k on the clock, so I figured the coils would be okay. But after inspecting the car after I bought it, it was apparent the previous owner had modded the car to some degree (came with a Greddy exhaust, lowering springs, and had rolled fenders).

I had my mechanic change the plugs for me when I had it in for service (oil change, etc). So I don't know if they were loose at all. I know they are stock plug wires. I'll definitely be ordering a better set when I get replacement coils.

The most recent thing I did to the car was put on a new set of tires/rims Saturday morning.

Thanks for responding Mazurfer/expo1. I'll pump up the tires, and check the plug wires and let you guys know what happens. I wonder if by resetting the KAM last night did anything since it's been driving normally since then.

shazy

Also, even if it wasn't misfiring check the coils and the wires. Last thing is, You broke the record man, 23 posts since January of 2002?! Guessing you are from the rx-7 club

Mazurfer

Possible resetting helped, but I'll bet the next long drive you take, it will come back. If those coils do have 47k on them.........then it's probably one of those or more going bad. Here's the procedure to check them, but honestly, I think you should get new ones.

http://www.finishlineperformance.com...16-07-1793.pdf


BHR has a nice new ignition system! See #12

https://www.rx8club.com/series-i-major-horsepower-upgrades-93/black-halo-racings-product-line-146611/

dannobre

iTrader: (3)

OMP, ECT sensor,Throttle body, acc pedal assembly, Those are the most likely "limp mode" suspects

You will have a CEL stored...that will tell you what went on.

No CEL..you likely weren't in limp mode..and then a lot of other thongs like ign or fuel will apply

Razz1

Yes, definately limp mode.
You rest the ECU so don't worry about it.

If it happens again or you get a cell then you need to check it out.

InfiniFC

iTrader: (8)

I had the opportunity to get into the engine bay and confirm the connectors and plug wires are snug and secure. Unfortunately I haven't had a chance to test it out. My front right tire was completely flat. It looks like it's badly leaking air from the TPMS valve stem after I filled it up at the gas station. And I JUST got new tires/rims.

You're right, I was originally on the RX7 Boards. LOL I think I joined this forum shortly after it debuted. I was on TeamFC3S.org, and RX7Club.com. 3 FCs, 1 FD, and finally an RX8 I'm now here.

Thanks for the reply snazy.

InfiniFC

iTrader: (8)

I suspect the same thing... I haven't had a chance to test it yet (damn leaking TPMS sensor).

Thanks for the links and feedback Mazurfer... I'll definitely be looking into these. So much for saving money this year. LOL

InfiniFC

iTrader: (8)

If/when it happens again, I really hope I get a CEL. At least then I'll have a better idea of what the problem is. It'd be fairly easier to resolve whereas having no error codes other than the symptoms to go on.

Thanks for the feedback guys, I'll let you know what happens once I get the TPMS issue fixed so I can at least drive it.

Regards,

dannobre

iTrader: (3)

With 47K...time for some type of new coils

Testing really doesn't work well...they often quit sporadically, which is weird for coils

InfiniFC

iTrader: (8)

Would bad coils be reported as a code from the CEL?

swoope

iTrader: (5)

did i die,

then a bit later run fine???

tpms limp mode does not exist..

if so fuel pump..

if you get a real cel. get back to us.


beers

Mazurfer

Just an FYI on the TPMS sensor issue. When I put on my aftermarket rims, I had a leak and it was the fact that the grommet on the TPMS wasn't sealing very well. I ended up having to use another gromment if you will(I actually used two.......one on the inside of the rim and one on the outside). The outside gromment was shoved carefully into the rim hole(if you will) over the valve stem, and then the valve nut was used to compress both gromments by the fact that they sat on both sides of a little lip in the rim hole and were compressed when the valve stem nut when on. Hope that makes some sense???? There's a thread on it somewhere, but the may have just cracked yours when they put it on the new rims, or you need a new grommet!

Dave

VOODOO8

For what its worth, was there by any chance some moisture getting into the intake via the CAI that would have fouled the MAF?

IF so, this would also throw in limp mode but also noramlly a CEL for a misfire. For some reason on my 04 MT I've seen this happen along with throwing a constant TPMS light (although the two should have nothing in common as was noted earlier in this thread). Since you've posted more recently about the flat tire, then maybe just a coincidental occurence there on the TPMS and the limp mode. Still not a bad idea to throw the MAF in the mix for a check/cleaning.

Vyndictive

iTrader: (28)

I would do coils first, then fuel pump... I think swoope has the right idea there. They're primary suspects in the type of power loss your describing (if you're sure its not plugs)

InfiniFC

iTrader: (8)

The car didn't die, but wouldn't give me any throttle regardless of the pedal being on the floor. After I did get over safely to the side of the freeway, the car was idling normally. It even revved normally which leads me to believe it was only effected when under load.

The car was low on fuel though not desperately low. According to the gauge it was hovering a tick over 1/4 tank. I did have an issue with the sender/gauge being inaccurate but had that fixed at the dealer under warranty. I confirmed the fuel tank level was accurate when I filled up at a nearby gas station the tow truck dropped me off. I also had used cheap gas on that last tank, so this time around I put in the good stuff. I'm going to toss in a bottle of Redline S1 injector cleaner to make sure nothing crappy is lingering on the injectors.

I got my stock wheels back on until I fix the leaking TPMS grommet. Been driving it to work (50mile round trip commute) and so far so good... The TPMS light is on since the front wheels no longer have the sensors.

My next service interval is coming up soon, and I'm planning on having my mechanic test the coils for me, and see where that leads me.

Thanks for the feedback swoope!

InfiniFC

iTrader: (8)

Yeah I believe you're right on that one Dave... I talked to my buddy who owns the shop that did the wheel swap for me. He said his guys had swapped the sensor a couple of times (for whatever reason). The other three tires seem to be okay, loosing only a tad of air (dropped 1-4psi since last week). I even tightened the nut a smidgen without any luck, so the grommet on my one wheels is definitely toast.

To be safe, I ordered new grommets from the dealer ($10 each ) for all four sensors. Now that I've addressed the issue with my buddy, I'm sure this time around they'll be careful and make sure there are no more leaks.

I'm taking a long road trip soon, and don't want to worry about flats especially since I don't have a spare!

Thanks for the feedback Dave!

InfiniFC

iTrader: (8)

It's definitely plausible that moisture could've gotten in. Here in the Bay Area we were hit with a small storm that drenched us in rain for a couple of days over the weekend.

My CAI is a custom setup utilizing the stock snorkle (bumper side of the engine bay) and stock air box. I modified the box to fit a conical K&N style filter within the box (ala Racing Beat REVi intake kit).



The grommets on the bottom of the stock box had deteriorated, and I just got an order of replacement ones. So I'll be checking the airbox and MAF when I replace those grommets.

Thanks for the tips Voodoo!

Thanks for all the input guys... Much appreciated! I'll be wrenching on my car to some degree this weekend and will let you all know how it goes... Though testing the coils will be done by my mechanic a little later down the line.

BTW, when I swapped my front wheels last weekend, I found that my stock endlink on the driver side stripped and almost pulled apart. So adding Racing Beat endlinks to my list of repairs. When it rains it pours!

swoope

iTrader: (5)

pm

beers

xlude

I had the same problem today. I was on the highway, driving a little hard when the car got slugish for a sec and the traction light flashed for a sec. I then I tried to WOT but it would go slugish again plus the traction light. Ever time I tried to speed up it would do this. It was like I was stuck in snow while traction control is on. I also had less then a 1/4 of gas too but I have before and never had this problem. Also I have another thread on here a couple days ago with a oil catch can problem. Anyway i got out of the problem by hitting the DSC button. When I did that I could WOT without a problem. I got off the highway and got gas. After letting the car sit for a min off. I started it and drove off without a problem. I drove home after work and still no problem. So I dont know if it was a tire or engine thing. I didnt get a cel either. I have a obd gauge in my car to see what the code would have been if one showed up.

Domenico

iTrader: (6)

Ok this happened to me too. I was driving 75 and felt like you stated you lost power, I had my foot on the accelerator and no response. Well mine happened because my tire went flat. I think it may be something in the car so you don't damage the car while driving. Put my old stock rims with tires and its been fine since.

dannobre

iTrader: (3)

Or a fuel pump thing