dzverko

Ok, i have searched and searched and done multiple different tests on the car but,it still stumbles and tries to die when the car warms up....
The symptoms:
-Every time i turn th key on to start it,the fans come on (no matter if cold or hot)
-When cold,car takes arond 10 minutes to start,at first doesent even sound like it is going to start,after a couple of tried it backfires a few times starts and dies,try a couple of more times and it starts but i have to rev it to keep it runnning,afer a while i idles by itself...
-Car idles fine and all gauges show normal readings (oil pressure,coolant temp,vacuum)
-When I start driving the car (not boosting),i would get the car to stumble an ty to litteraly die on me (not 3000 RPM stumble),i would let go of the gas pedal and get on it again and it would be fine for a few seconds
-When the car tries to stumble and i give it a little more gas it will start sounding like a backfire from the intake?
-I would also get a check engine light to come on and shut right off when the car stumbles but with no code stored in the car (i know pins TEN and GND)

What i have done so far:
-changed spark plugs and wires (Magnacore 8.5 mm and all 9's plugs)
-flushed cooling system and bled at least 3 times
-checked all vacuum hoses at least 10 times
-checked precontrol and wastegate actuators for vacuum leaks and if they are mounted correclty
-checked grounds for proper installation
-no leaks under the car
-checked MAP sensor vacuum line as well
-Tried disconnecting the O2 sensor
-Tried reseting the ECU
-Tried running car with some water for a stuck seal (rear from one of my searches)
-even looked for disconnected connectors somewhere in the engine bay (with no luck)

Mods:
-HKS downpipe
-HKS cat back
-Reman engine with around 30K
-Swapped turbos (stock seq.)
-All reliability mods


Am i missing something? Has anyone ever had the same problems (i've read of similar problems but not the same ones)? What other tests should i do? Can someone suggest anything at this point. I am very stubborn and i feel like my RX-7 has got the best of me at this point (RX-7 => <= Me). Not to mention that all this happened all of the sudden one morning when i tried starting it!
If i am missing any info that you would like to know,let me know and i will post it!

PandazRx-7

iTrader: (18)

Hmmm...might be the water thermoSENSOR and/or thermoSWITCH malfunctioning. Could be sending the wrong single to the ecu, which in turn is running the car rich, etc. Could explain why the fans are on when cold as well the backfiring and hard starts...

They're behind the WP housing to the left of Alt. Change both switches, they're right next to each other.

Youngsity1986

check the smog pump pulley

dzverko

I forgot to mention that the Air pump has been removed...

dzverko

PandazRx-7 :
That is a good guess about the waterthermo sensor but wouldnt that set the check engine light (might now i dont know)... anyway tho i will try....Also how hard is it to replace and where can i find some procedures to do the job...Its worth a shot and i hope that they are not that expensive anyway...Appreciate your help!!!

dzverko

Well i just spoke to my local Mazda dealer and they said they could have them by next week Wednesday if i order them today...Is there a way to just bypass these 2 sensors so i can varify that the sensors are the problem or is the only way to know by just replacing them?

gracer7-rx7

iTrader: (16)

you can and should buy OEM parts from Malloy Mazda. He has them in stock and shipped to your door with great service. Ray Crowe is the parts manager 888.533.3400.

no idea on your problem, but I would suggest downloading the Factory Service Manual (FSM) from the stickied FAQ thread in this forum. That will tell you how to test these sensors before throwing away money replacing stuff unnecessarily.

fyi - removing the air pump and running the stock cat is generally not recommended.

PandazRx-7

iTrader: (18)

Well, I couldn't get a stored code from the ECU when I had a similar problem years back...as a matter of fact it would come and go and tease me when the problem happened.

I would hate to see you just change things out and spend money without knowing 100% if this is the problem...But if you're at the stage I was at, I'm sure you don't care at this point and want to just try it. I recall the switch was about $30-$40...definitly talk to Ray at Malloy if you want to order it...

From what I remember, you need to only take the Alternator off and the small coolant hose to the left of it to gain access. Make sure you have a regular wrench cause a socket won't be able to fit over the switch.

Oh and Gracer is right, your stock cat needs the airpump, could be that it's toast by now and it's choking your motor...

Btw, if you had a PFC, you might have been able to check on the sensor from the commander...