Venkmen

Car is an '04 Stock except K&N drop in filter. Currently has 71k miles on it. Plugs, coils, wires and battery were all changed at approximately 65k miles (4 months ago). Oil is changed regularly at 3k miles and I check the level every second fill up and top off as needed with non-synthetic. Was planning on giving the sea foam treatment in the next week or so, but the following happened and now I want to get this straight before I continue.

Car was bought used a year ago and all recalls have been completed per the dealer. Over the past month or two I have noticed a slight loss of power and my gas mileage has been tapering off slightly. If I go up any kind of hill I have to drop to 2nd gear and give it WOT or the car will die and even then it chugs. On level ground it still performs well (loss of power since I bought it though). Two weeks ago a CEL came on for code P0037. O2 sensor in the cat is bad. Everything I read on here says that the car should run fine without it so I was going to wait to fix it.

Well Friday coming home from work I had just gotten off the Interstate and hit some traffic. When I pushed in the clutch and press the brake to slow down, BOOM. Car died and battery light came on. Got the car over to the side of the road, tried to start and nothing. The car was turning over just fine it just wouldn't fire. I sat for a couple of minutes trying to decide whether to call my girlfriend to pick me up or a tow truck and then I tried to start again. Turned over fine again but this time I could hear the engine trying to fire....just barely. Let the starter cool down for a few and then tried again. Same thing but a stronger sound coming from the engine. After about 7-10 minutes of this cycle the car fired up and I was on the way.

I got to my destination to pick up a friend for some 4th festivities, never stopped the engine and then headed home. Leaving their house which is on a slight incline the car was trying to die. I gave it WOT in 1st gear and climbed the slight hill and once on flat ground started running normal. Hit traffic again, pulling up to a stoplight, push in clutch, hit brakes to stop and BOOM....dead again. I performed the same sequence as before and the car fired up after approximate 7-10 minutes. Drove to Auto Zone to check if any other codes had popped and it was still the same...only P0037.

The car has sat since then due to family plans over the weekend. Any ideas on causes? I have been suspecting a clogged cat for a while due to the power loss and I have a suspicious that the car has seen some high water. When I changed the plugs, coils and wires the two bottom plugs had substantial rust on them, especially the rear bottom plug.

I have tested the battery and alternator to rule them out. They both tested fine. Car has been idling in the driveway for approximately 30 minutes and has not died. When I go WOT on it the engine revs smoothly, but when it is coming back down to idle it seems to chug a bit at the bottom end. RPM's fall to 500 to 750 and then they pick up and level out again between 750 and 1000.

Am I thinking correctly with the cat or could I be looking at a fuel delivery problem or worse?

Any input is appreciated!

Juansito

iTrader: (5)

i think your right about the clogged cat. I think your covered under warranty if it is the cat not too sure though.

Venkmen

I will find out soon enough. I am going to be dropping the oil either today or tomorrow and will pull the cat while I am under there.

monchie

Keep us updated. I think mine's having the same problem like yours. I may need a tune-up or something.

tonik

It could be your fuel pump...Same issue here...Am on a 2nd week now of Walbro fuel pump and so far the car never stalled..Try searching Fuel pump.

alnielsen

iTrader: (4)

If it is your fuel pump overheating, you can test for this by putting fresh gas in the tank. If the problem goes away with the cool fuel (no pun intended), then it's the fuel pump.

StealthTL

iTrader: (1)

More likely pump than cat - the symptoms are definately not cat related.

A cat impedes exhaust flow, so when you try to go fast it 'clogs up' and you go slower and slower, but has very little effect at idle and would never stop a car trying to start.

A fuel pump will do exactly like you described, just give up for a while, then restart later, setting no CEL codes.

I took tthe car to the dealer a few times, and they found nothing - if it doesn't record a code they are blind, so I took the tech and his laptop for a quick highway run and the car was going slower and slower, then just died in the road - all the time the tech is saying "no, nothing wrong, the computer says everything is normal....." Finally I told him we were blocking traffic and could he help me push it off the road!

Then he got me a new fuel pump.

monchie

At least replacing a fuel pump is cheaper than having to replace the coils, plugs, and wires

MazdaManiac

iTrader: (3)

Actually, no. It is not.

acherry370

i have the same issue except today my car over heated it stalled like u say yours did yesterday and the day before but after today when it over heated and the coolant was boiling i added more coolant and now it acts like i just put in a new motor

Grace_Excel

iTrader: (5)

I like your approach

markman242

I doubt its the pump, poor fuel pressure would give you a horrible startup due to the command for rich fuel at cold startup. Take it to the dealer and get a compression check done on your engine especially being a 2004.

SpIcEz

Actually you are wrong.

The failures with the RX8 pumps is they have problems when warm. So you would have no symptoms at cold startup.

I had to change mine last year.
MANY here have had to change their fuel pump and some have done it twice already.
Thankfully, I diidnt buy another OEM one, I went with a walbro right away.

Rodlucci

Sounds like a trip to a dealer for a compression test would be of value. Your symptoms are very similar to mine. My engine was replace 125 miles ago.

monchie

So smart ***...it's cheaper to replace a fuel pump than replacing the plugs, wires, and coils.

Brettus

iTrader: (2)

/\ thought someone such as yourself would have swapped in a new pump well before the old one had a chance to fail ......

SpIcEz

I was unlucky because the plastic wring holding the fuel pump assembly was somehow seized, don't ask me how (maybe winter grime...).

Even Mazda wasn't able to remove it with their 4 pronged tool.

I had to order a new ring and cut out the original to replace my fuel pump.

Fricken plastic ring is made in Germany and cost 90$ is Canada...

MazdaManiac

iTrader: (3)

No, dumbass, it isn't.

The fuel pump is ~$270
The coils are $120 a set, the plugs are ~$70 and the wires are ~$35.

How is that math thing working out for you?

SpIcEz

In all honesty, and with less rudeness, BHR and many others offer the Walbro fuel pump for 100$ and it drops right in... as you well know !

Now as to which is the best option for diagnostics purposes, that would depend on the symptoms, of course.

Razz1

Can't go up any sort of hill is a CAT

MazdaManiac

iTrader: (3)

Not even part of the original question and rudeness meets rudeness, observe the content of the dialogue before you comment on the delivery.

SpIcEz

About the original question, What do you mean? You where comparing OEM prices, when there are aftermarket alternatives, did I miss something?

About reading the dialogue, I it did. I had you quoted so must have taken it personally, in honesty I meant it in general.