RX7Club.com - Mazda RX7 Forum - Won't Rev Above 3600, Won't Idle. Help.

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Won't Rev Above 3600, Won't Idle. Help.

Ok so the car started for the first time tonight.. started smoking bad but that went away... now it won't go above 3600rpm's and it won't idle... the tach just dies and the motor shuts down... alomost like it shuts itself off. n e ideas?? i want this thing running right so i can drive it.. :bigthumb:

mike

ok i had this problem

First compression on engine???

Second... u have a MASSIVE vac leak... and i know your saying nope i have found em all(same happned here) u do have one find it....(took me 3 months to find mine)

Also a loose ground try that and post results

will do.. looks like thats what i'll be doin tomorrow..

thanx man

well i'm not finding n e vacuum leaks.. n e ideas where one could be??

Vac leaks don't just come from cracked or old vac hoses. Check and silicone the connecting points. Check the grommets. Also, did you check the following:

-AFM
-Clean BAC
-Thermowax
-Intake manifold seals
-Throttle plates and cable
-TPS

I'm still looking for leaks myself. My idle is fluctuating between 1300-1600rpm. I checked all hoses and cleaned the BAC, and adjusted TPS (which I think might be going since the resistance was at 6.32kohms at WOT). I will check the AFM tonight and see if that is the culprit.

use a vacuum guage to tell if there is a leak first off. Second make sure your AFm is plugged in as well as the sensor on the back of the waterpump.

ok i will check all those.. if you can give me a little more onto what you just told me are that would help.. LOL remember this is my first rotary..

also a few more symptoms.. it sounds like it has missfire where it sputters when i hold it constant... goes away when i give it throttle...till i level of again.. on a down rev it will give me a little backfire everytime as soon as i let off the throttle i got it above the 3600 mark it just hesitates there for a second... but still below around 2500 the tach just drops to zero and the motor shutsdown.. giving it throttle doesn't even faze it... it won't come back it just dies.. and it struugles to restart but it will always restart.. i'm lost here..

TIA..
Mike

non of the plugs in the pics matter for your situation. the clear 6hole plug near each front strut tower is for the aas electronic suspension which your car obviously does not have, so don't worry about that. the yellow 2 hole plug near the pass strut tower is used to turn the fuel pump on with a jumper wire between the 2 terminals. the clear 3 hole plug looks to be a check connector for a mazda dealership tester, so that's not the problem either. and the black single wire plug is for an electric fan which your car doesn't have so that's not it either. and the 2 green plugs near the leading coil are for mazda diagnostic devices so don't worry about that. it kinda sounds like the problem is in the air flow meter. it can do tricky things to the engine when unplugged or faulty. even with the air flow meter unplugged the engine should start and idle but when you try to give it gas it will sputter and backfire and die. don't waste time on anything else until you make sure the air flow meter is working properly. try to find another known good one and swap it in to see if that cures the problem. then maybe try the ecu. ecu's don't normally go bad unless someone has done something stupid like hooking up the battery backwards.

and even if the air flow meter does make it better and it still won't rev above 3600 rpm it could be the injector resistor pack located under the airbox on the pass side fender well (it's a small silver box). but your car will only have one of these if it's a 87.5 and earlier.

your welcome man, hope it helps.