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Fuel pump, Cats, or coil packs, plugs and wires first?
Ok guys, my '04 GT is down. I need to figure out what to do to fix it soon, as the GF isn't very happy with me having to use her car every day now.
Here's the symptoms and what happened...
Note: for a couple days before this happened, I was smelling a "burning plastic", or "burning electronics" smell after driving for a while...
Also, I was guilty of letting the car run low on gas for a few days before all this, so this is why I think it could be the fuel pump... As it suddenly started sputtering and acted like (if it were a piston engine) it went from 8 cylinders to 2 all of a sudden. Like the engine is struggling with no power at all. Check engine light flashing as of course; misfiring...
The car will start, but won't stay running unless I keep trying to give it gas. Will not idle... It just sputters out and dies.
Here's the codes I pulled:
P0300 -- Random/Multiple misfire detected
P0301 -- Cylinder 1 misfire detected
P0171 -- Fuel Trim too Lean (Bank 1)
So, could that "burning plastic" smell I was smelling, be the fuel pump getting hot and burning up (because I was running it low on gas)??
I don't have any kind of gauges to properly test the fuel pressure, but I did pull the line off of the top of the fuel pump, and it IS pushing out gas when the key is turned on... I could hold the pressure with my finger (btw, now the quick connect fitting is leaking, so that's another thing that needs to be fixed!)
Or should I start with something else like checking the Cats, or changing the plugs, wires, and coil packs? I think the latter are about 30k miles old.
Well, though nobody responded to my post, I want to thank you all for this site and all of the useful information here. I was able to get the car running today. I replaced the fuel pump (I rented the special tool for the ring from Autozone), and fixed the leaking fuel connector. I also bought and replaced the coil packs, plugs and wires, cleaned the MAF sensor and the (what I call the crank sensor - I forget what it's called here) also installed a new air filter.
She's running great now! Much better... Lots of power!
us autocrossers run on a low tank all the time ...
Well, it's one thing to run it low for racing purposes, but for a car that's used for daily driving and a primary means of transportation, I don't think letting the car run low on gas frequently would be recommended by anyone.
I've got to say though, since fixing everything, the car has been running great! I honestly think my gas mileage has almost doubled as well!
Last edited by BlackRX8_04; 07-09-2015 at 08:08 AM.
Don't worry about the lack of attention. Your post was during the big July 4th holiday. We all still care, we were all just at barbecues or at the beach with our rides and friends!
I agree on testing and figuring out what was wrong with your car than to replace everything. Running "low on fuel" does not necessarily make the fuel pump fail and "melt."
In fact, I feel none of those are going to produce a "burning plastic" smell. The power could be due to it not getting fuel, aka it running lean. How did the car run after you put fuel in it? What is "running low" mean? Like running on the reserve tank 24/7?
How often is "frequent?" I don't think an RX-8 seems like a car for you if you don't have the money to at least have it not hit E everyday - you do know you should be topping it off with oil every other fill up too right? This car is a money pit, though as awesome and fun as it is.
BlackRX8 04, Running "low of fuel" combined with heavy load on the pump (example:Hours of high speed highway driving) puts maximum load and heat buildup on the Series 1 pump , with not much fuel surrounding the pump to dissipate the heat, and is the classic scenario where these pumps overheat and shutoff, as they now are all aging fuel pumps on all Series 1 RX8s.
BTW what pump did you replace it with? A Mazda OEM pump or equivalent from Autozone ? It does make a difference what pump you chose.
Last edited by gwilliams6; 07-12-2015 at 08:06 AM.
I agree on testing and figuring out what was wrong with your car than to replace everything. Running "low on fuel" does not necessarily make the fuel pump fail and "melt."
In fact, I feel none of those are going to produce a "burning plastic" smell. The power could be due to it not getting fuel, aka it running lean. How did the car run after you put fuel in it? What is "running low" mean? Like running on the reserve tank 24/7?
How often is "frequent?" I don't think an RX-8 seems like a car for you if you don't have the money to at least have it not hit E everyday - you do know you should be topping it off with oil every other fill up too right? This car is a money pit, though as awesome and fun as it is.
Thanks for your post. Yes, I'm well aware of the rotary engine's oil consumption... and I'm a 46 year old professional; I'll decide if "this car is for me" lol
I agree with other posts. It is not advisable to continually run these cars at low fuel levels. Even your new pump will not last if you continue to do that. Hopefully you have decided not to continue that. Cheers ,and best to you !
Last edited by gwilliams6; 07-12-2015 at 08:56 AM.
The point was we run it low on a regular basis under both high engine and G-force loads without having any more issues than anyone else. The idea that you drove around with a low tank and killed your fuel pump as a result is not accurate. The more obvious conclusion is that your fuel pump was already at the end of it's life.
The point was we run it low on a regular basis under both high engine and G-force loads without having any more issues than anyone else. The idea that you drove around with a low tank and killed your fuel pump as a result is not accurate. The more obvious conclusion is that your fuel pump was already at the end of it's life.
It is never a good idea to overheat any Series 1 OEM fuel pump on a regular basis. Yes since all original series 1 pumps are now very used and old, they are nearer the end of their lives. Its flaws as it ages ,are why Mazda ditched it and put in a better pump in the Series 2. That is why I put in a Series 2 pump.
Oh seriously TeamRX8, there has been so much thread discussion on this over the years. It is an injustice to tell any new owners of used Series 1 cars that this does not occur in many older pumps under heavy load with low fuel levels.
TeamRX8 post your data to show it is NOT happening. RX8 Series 1 owners' experiences with this problem are all the proof needed. Mazda saw the problem eventually and changed the pump, why can't you see?
In the classic scenario of these Series 1 fuel pump failures, once the pump was allowed to cool down, the cars started right back up again. And when the fuel levels were filled back up, the pumps continued to work again. That happened several times to me personally after heavy load, high temp scenarios and low fuel levels.
A couple of longtime Rotary wrenches I know, with way more experience with RX8s than even you and I have put together, have also seen this as the problem. There is no real debate on this issue, unless it is in your own mind. If you never personally experienced this, then you are fortunate.
Last edited by gwilliams6; 07-13-2015 at 10:34 AM.
what I see is you have no real experience on the subject as usual, yet you once again try to mouth off as someone expressing an expert opinion based on speculation, theory, and opinion against the people who do.
running a pump continuously empty will ruin it for sure, yet you have not one shred of evidence that this even occurred once let alone the hundreds if not thousands of times it takes for it to happen.
I'm not debating anything. Try rereading my original post. It was only sharing real world experience by a group of mostly S1 owners who have been running low tanks more than usual. If you want to refer directly to me it's 10+ years of experience. I don't even remember that last time my tank was above 3/8 level and the yellow low fuel light is on most of the time. Ad also using E60 fuel for the last several years to boot.
Every time we have these discussions it always comes down to what somebody else told you.
well, I can't proof that pump is overheating cuz I dont think there is a way for me to point my thermal gun at a in-tank fuel pump while it's running inside a sealed tank
but, one thing I'm sure is that the pump suck ***, there are a few rx8 here having strange shut off issue, it's not ignition, the car will just shut off on it's own when it's low on fuel. fill the tank up, problem is gone, anything less than 1/2 , chance of car shutting off on it's own is about 50%, anything at or below 1/4, 90%
so yeah, S1 pump sucks.
and it's a well known fact that fuel cools in tank fuel pump, when you are low, fuel pump heats up.
TeamRX8, I always go with my own personal experiences first, and yes I talk with others who have had the same issue and have solved their problems. No guessing, no speculation, just actual experiences and actual solutions. You can deny the problem with these pumps, but for many of us who have experienced the problem firsthand and have found solutions, we know what we are talking about, even if you don't believe it. I now have a new Series 2 pump in my 2008 40th AE RX8.
Time to move on TeamRX8 when it comes to this discussion. Like the movie line says , "Let it Go"
Last edited by gwilliams6; 07-14-2015 at 11:54 AM.
but, one thing I'm sure is that the pump suck ***, there are a few rx8 here having strange shut off issue, it's not ignition, the car will just shut off on it's own when it's low on fuel. fill the tank up, problem is gone, anything less than 1/2 , chance of car shutting off on it's own is about 50%, anything at or below 1/4, 90%
so yeah, S1 pump sucks.
and it's a well known fact that fuel cools in tank fuel pump, when you are low, fuel pump heats up.
Having same problem at 92,000. New pump will be here tomorrow for weekend install!
07-04-2015, 01:50 PM
