Throttle Body Behavior
 

Howdy folks,

So need some assistance, working on an '04 with ~80k miles. Car was started twice today for some short moves now it won't start at all. Original thought was flooding. Waited a few hours tried to start it still no go. Pulled the plugs to find out they where completely shot, so we replaced them but the car still won't start.

In the process of doing all this we noticed a very high pitched squeal coming from the throttle body. Going though the trouble shooting guide in the FSM, the throttle body passes inspection, however I still question it.

What is the normal behavior of the throttle body under start up? When we put the key in the ignition the throttle plate doesn't move, when we turn the engine over the throttle plate still doesn't move. It would seem to me that the plate would need to open in order for the engine to take in air to start.

Anyone have any ideas or suggestions? James did I leave out anything?

nope that about covers it someone please help

charles,

the car is trying to turn over just not starting, its getting spark and you can feel the motor try to start. the battery is good and the started is good. is there anything else you guys would recommend testing and/or replacing.

thanks again everyone

Starter isn't spinning fast enough?

Charles you flatter me, I wish I had a shop, I'm just an avid rx7 owner trying to help out my rx8 brethren. I have quicky discovered that the 8 and 7 are quite different. I'll be heading over to James' house with my compression tester after work and I'll post the results. Thanks for all the help!

just had starter tested, motor is fine, but the solenoid is done. new one will be here in the morning hopefully this will correct the issue if not compression test is next

So when the solenoid is done the car wont start? Cuz im having a problem right now i have thread made on here my car didnt want to start but we and after a few hours it started but shaking severely i changed the spark plugs and then turned it back on and the shaking is still happening

Sounds like it is/was flooded.

The shaking is probably one plug not firing, sounds like you need to get the engine hot and see if it behaves. See if the shaking stops after a good fast drive to clear things out.....

S

the throttle body will make a bunch of noise sometimes even when the engine is not running. it will also stay partially open when engine and ignition is off. a buzzing or squealling is also normal. the pcm actuates it to either rezero the position sensors or a programmed opening to prohibit sticking.

You just couldn't help yourself could you!

if the solenoid is limiting the power that the starter motor is receiving than yes. If the starter isn't spinning fast enough the engine can't develop enough compression to start.

Did you mark and reconnect the plug wires correctly...and mnake sure the plug wire boot was **really** pushed until it clicks?

replaced the starter this morning still having the same problem, car is trying to turn over but nothing. any ideas of where to go next???

well, just finished the compression test, its 60 in the rear and 70 up front. looks like i'm going to need a rebuild. does anyone have any ideas where to get the best $$$ for a kit??? please let me know, and again thank you all for your advice!!!!

Please give us some more info... How many miles? What service and parts has the car had? M/T or A/T? Have you been having any other problems. What mods have you got? Where are you? Do you have a Rotary compression tester?

with a traditional compression checker @ 208 rpm's

There are three sides to a rotor....traditional will give you the highest side of three sides. The engine warranty is 8year or 100K. Are you over that? With a speed of 205rpm it sounds like a old style starter 2004 or 2005 and a weak battery.

going by the chart in the FSM at 200rpm the compression should be 102psi. James is going to jump it and see if the starter RPM increases to see if we can rule out weak battery

no speed increase on the starter even with the jump. He is getting it towed to Mazda to have them check it out.

the car has 82k on it. parts, i've replaced the battery about 5 months ago, replaced the starter yesterday. its a m/t i have never had any problems with the car until monday when it decided to die on me. as far as mods go, it has an aftermarket exhaust and intake, but all stock besides that. the car is in south carolina. rotary compression tester i do not have. we did a standard compression test and it was 60 in read 70 in the front.

Just an update for everyone, James took the car to mazda, turns out the car needed new wires, new plugs (again) and an ECU upgrade. Thanks everyone for all the help!

So it was flooded. I would replace the coils for good measure so you know that you are starting relatively fresh as far as ignition goes.

I had the same issue and ..
 

As far as the high pitched squeal coming from the throttle body. I had the exact same problem cept every now and then the squeal would go away and at that point my car would start! So I took the throttle body off when the car wouldn't start. Drilled out all the rivets in the throttle body. Took out a small electric motor and hooked it to 12 volts. It usually gets 5 volts. After having hooked it to 12 volts I realized the motor was getting stuck on the small 5 volts. It's bearings inside were bad and the motor was freezing up! I oiled the bearings in the motor and voila it worked after bolting it all back together. I put bolts and washers where the rivets once were. It squezled however and only lasted a day. But it got me home and no I didn't need a compression test like everyone else likes to recommend. When the throttle body first started going bad my car had troubles starting from time to time and got progressively worse. Til eventually it started dieing coming to stops and had very poor acceleration from a dead stop. My car is an 04 rx8 with123000 miles

symptoms of bad throttle body
 

I had the same exact problem. I wrote a whole thread in response to you earlier but placed it under some other thread. I have an 04 rx8 with 123'000 miles. Mine did the same thing. When I heard the high pitched screeching sound coming from my throttle body my 8 wouldn't start.occasionally the noise went away and then it would start. My car would die coming to start and occasionally had problems starting. I verified the noise was coming from my throttle body by simply disconnecting it and the noise went away. As the problem got worse my car had troubles accelerating from a stop and then later became harder and harder to get started. The throttle body would be hotter then the engine. There's a small motor in the throttle body it was worn out. Everyone recommended getting a compression test.I recommend you get a new/used throttle body. If you want more confirmation your throttle body is bad. Take the throttle body off the car. It's riveted together. Drill the rivets out. Take the throttle body apart pull the lil motor out. Try spinning it with your hand. Sometimes it'll get stuck. The bearings inside it went bad. Oil the rods in each end getting oil into the lil motor reassemble the throttle body using small bolts, nuts and washers . Turn your car on hear it run. Replace throttle body immediately add this wont last. Your welcome. Also anther easy to tell if it's bad is the throttle body will become extremely hot just leaving the key in the in position without even starting the car. If you listen to the high pitched squealing electronic noise and after cycling the key on then listening for the sound to not be there then Try starting! I turned the key on heard the noise.turned it off and on till I didn't hear it and only then would my car turn on.

What would be going on with the tb if the high pitch squeal is inconsistent, more specifically has interrupts between the squeal?