ok guys i just bought a 88 mazda vert non turbo ok guys i replaced the starter the alternator and now im having problems when i first start it i can rev it up but after it warms i press the gas and it goes from 1000 to 2000 rpms no higher i have new spark plugs i have not installed yet any more suggestion guys>?\

 

does the throttle move all the way under the hood when you press the gas???

 

yes but last night i ran it and no problems but it does back fire more thanks for the suggestion

 

well today at work i changed my plugs i dont know if it still back fires yet but it seems to idle a little to high round 1100 to 1200 rpms right now if anyone could help please feel free to do so thanks

 

is it an automatic and are you reving it in neutral?

 

its a 5 speed

 

another problem after the other now when im driving it(no gear in paticular) it seems to jerk a lot like something is slipping or goin out

 

Does the rpms bounce when you try to rev it past 2000?

You have an 88 so that engine will run without the TPS, Pressure sensor, water thermo sensor and a few others. Basically You need the injectors and AFM for the engine to run. May not idle correctly or have lots of power but it will run.

Everything else controls Air fuel delivery basically. If there is a sensor giving a wacky reading to the ECU and the ECU is applying a fuel cut at 2000 rpm, then you can try disconnecting a few items. My engine had fuel cut at 2000 rpm once and it was because of the TPS. I had to jump the initial set connector which is a 2 prong green connector near the leading coil (near the battery). What this does exactly.... I dont know. I just know that your supposed to jump it when reseting any adjustments. This may help?

I also had a fuel cut at 3000 rpm due to a vacuum leak at the PCV near the oil filler neck. Very strange this one was. The PCV broke causing it. replaced it, engine ran fine. I have not diagnosed this further but im guessing in vacuum leaks at the TB nipples could cause weird situations such as fuel cut?

Check the throttle body and make sure the throttle plates are opening completly. If the primary opens all the way and not the secondary then your engine should still rev up near and past 5000 rpm with loss of power after 2300 rpm.

Check your AFM and make sure the flap is moving freely. Also check it with an ohm meter to make sure its within spec. Factory Service Manual is here
http://www.teamfc3s.org/main/factory...ual/1986_1988/

The jerking could be associated with the fuel cut if that is your problem.

 

The high idle could be a vacuum leak.

Did it idle high before when you got the car?

 

i just got it last week its not a vaccum leak im sure of that maybe the throttle plates though when i get home imma check them out thanks you

 

well guys could it be my clutch thats what my friend seems to think

 

i used a honda trick today using that sea foam cleaner through my vacuum lines and cleaned out my throttle body too but i only got a chance to do one vacuum line but tom i will do all of them damn the engine was clogged up now she runs a lot smoother

 

Alright I hate to bring up old threads but I searched and this sounds exactly like what my car is doing. When I drive my car somewhere and it warms up I will stop driving and get back in (like after a 30 minute shopping trip) the problem crops up. Usually I can just putter around a bit and it fixes itself but its made my car really unreliable.

Pretty much car gets warm and then will start but when in neutral (5 speed) or any gear with the clutch in I can floor the gas and it just revs to 2000 RPM then sounds like power is cut and drops to 1200 then back up to 2000. I have replaced the fuel filter, air filter, catalytic convertor, and have spark plugs if thats the problem. The throttle is moving when I push the gas in.

I have a 91 RX-7 non turbo. Any suggestions? Thanks.

 

Try revving it AT the throttle body.

 

Tried that... Same problem. Any other ideas?

 

A few years ago now that I remember, I had a similar problem. I forget what caused it. But after disconnecting the battery for about an hour and reconnecting it. The problem was gone. Why this occured our how disconnecting the battery fixed the problem is beyond me. I have a 88 though.

 

You think that unhooking the battery resets some of the settings to default? I will try it this weekend and let you guys know how it goes.

 

I think that will remove the stored codes in the ECU. On an S5, that could take it out of limp mode. But... that's just speculation because I don't know much about S5's (S4 > S5 so why learn ).

 

I am not sure if the ECU settings are what is causing it since it only does it when its warm. Only one way to find out. I will let you guys know.