Mickh

okay well when I fill up the gauge doesn't go up it goes up abit and then starts decreasing and it's really annoying because no matter how much I fill up it won't go up a lot also it hasn't been on full in a while now

StealthTL

iTrader: (1)

The sensor used in the tank can get contaminated by a certain amine used in gasoline treating.

Bought any cheapo gas lately?

Symptoms can be cleared up with a dose of isopropyl alcohol into the fuel.

It's available as IPA, Iso-Heet or 'fuel line antifreeze for fuel injected vehicles'.

IPA dissolves into the gas and causes no bad effects, about 10/12 ounces in a tank of fuel should do the trick.

Worth a try?

Mickh

nah Iv been using premium 98 octane I'll give it a go see how works thanks I just hope that works out for me

Alexandru Ciureanu

I guess i have a fuel related problem as well...

This is what happened:

I filled up from some no name gas station (arround 33 litters) and added 150 ml of Motul 710 2t in the tank.
After driving for 5-7 mins. the rpm dropped to 3000 rpm and refused to go above (i have a ecu rev limiter for cold engine set at 3000 rpm and a lowered fan temp initiation).
The car would only go above 3000 rpm only if let to idle for a while and than driven at high rpm. I also noticed that it manages to pump more heat in tha cabin when the issue goes away.
The issue was easier to overcome after i refilled with some known good gas (aprox 30 liters) and no premix, but the issue still present.
I should mention that the outside temp. was about - 5 C.
It did not loose any power at any moment.



Even more weird, I disconnected the + from the battery as I thought this should reset something in the ECU and the decat engine light went away and DID NOT COME BACK after 150 km. No engine check light now!

Do you think it is possible that the gas was that bad that the engine would not manage to heat up? I drove like this for 250 km. Do you think i could have damaged smth in the engine? What else coud be?

Loki

iTrader: (1)

Fuel doesn't cause your engine to produce no heat. More likely your thermostat is stuck open and it overcools at speed, or the threshold for your 3000rpm limiter is set way too high.

Also, disconnect the negative cable from the battery before you disconnect the positive. Not doing so risks you electrocuting yourself.

Alexandru Ciureanu

Thank you!!

Makes a lot of sense! 2 days before filling up I drove in the snow drifting for 2 hours at -12 C. maybe it overworked the thermostat. I haven't driven the car in between the two. I will get an obd reader and experiment with it to check on the coolant temp.should indicate if it is really cooling down.

What would be a good thermostat to replace it? Is the Mishimoto a good choice?

Alexandru Ciureanu

is there a chance of engine damage? I use 15w40 mineral.

oh.... is there a chance to have a faulty fuel pump? someone suggested that it is not generating enough pressure. and it builds pressure at idle, but i have to point that i drove for 10 mins at 6500 rpm and it had no issue.

Loki

iTrader: (1)

"overworked the thermostat" is not a thing. But yes, get an OBD reader, it'll clarify things. It also sounds to me like your rev limiter, whatever that is, is too aggressive. If the trigger temperature for it is just a few degrees below normal operating temp, you'll be tripping over it all the time.

You say you didn't lose power, so I don't think it's your fuel pump. Fuel pump problems don't usually have a nice clean breaking point at x rpm.

Alexandru Ciureanu

Thanks again!

i plugged a obd reader and got the temps:
[ 2 C outside temp]

- 84 around town = slow driving
- 87 long idle
- 73 at 90 kph and 2850 rpm

it really looks that the thermostat is stuck open. I also have a lowered fan trigger temp. What do you think about installing a mishimoto thermostat (76 C opening temp)?

Loki

iTrader: (1)

I have the mishimoto one. There is no advantage to it. There are also no disadvantages that I can see (and I drive in canadian winters). Since the lower temperature seems to be tripping your rev limiter, if you add a 76C thermostat you'll be tripping over that all the time. So might be better to stay with a Mazda one.

KUWIROCKS

Hey all. I recently purchased a 2005 RX8 and notice when first driving it for the day, the car seems to stutter/get jumpy around 35-40 mph when driving at a constant speed. I especially notice this when I going up the hills. When the car is all warmed up after driving for 15 or so minutes, the problem isn't noticable except on hills. Is it safe to assume this is simply a fuel pump issue?

Shpe1482

Hi

I can’t pull off on 1500 rpm, car stutters like it’s not getting fuel. Once I pull off over 2000 it works good. Also sometimes if I’m in traffic or stop idle drops and it cuts off, Anyone know what it is? Compression tested 100 in the front and 95 in the back. Thanks

TeamRX8

iTrader: (25)

There’s no guessing this. You have to at the very least temporarily install a pressure gauge that you can read while driving the car. Either there is good pressure or there isn’t. No opinion on a internet forum can determine that.

It sounds more like an ignition issue to me, but honestly it could potentially be a dozen or more different things

Shpe1482

Hi, all I did yesterday was change spark plugs, coil packs and coil wires it only started after I did that. Maybe a bad coil wire or plugs . How do I test the file pump ? What do I need to get ?

Josh Wright

Im having same issue car jerks and like its choking when i accelerate. When i get around quaryer tank of gas or when its above 80* f or after driving car around 20 min or so is when it starts to jerk badly when accelerating as if its not getting gas or power and i just put new battery and new plugs wires and coils in less than 5k miles ago so not sure if coil or plug has gone bad already or if its cat or fuel pump but guessing its fuel pump since cat doesnt glow red whats confusing me is why when i put octane booster in car or when its cool outside the issue doesnt happen near as often. Please help and if its needing fuel pump how difficult is it to replace yourself for average person?

Kimura

In that case it's not the fuel pump. You need to verify your work and the parts you installed.

juspe

Hello guys!

I got P1688 (OMP problem) in 2004 RX-8.

can it be deleted and permanently erased whole thing with some software? To manipulate ECU so it doesnt matter.

I have checked OMP etc and I oil my car with 2-stroke to gastank.

So I just want to get the code away.

And... my car is also in limp mode, ofcourse.

Please help - software and advices needed.