My rx is idling at 1500 and backfires when I drive it has 4k on rebuild with street port how do I adjust timing ?

 

Use the advanced search feature and you will find many posts including pics on how the timing is set. 40 seconds of searching unearthed the following thread.

https://www.rx7club.com/2nd-generati...timing-742026/

And what happened with looking to see if the fast idle cam screw was there or not? I mean if people are going to spend time in trying to help you then you need to keep us up to date or people will not bother.

 

welcome to the board.

... and (respectfully) please stop making NEW threads to cover the same issue. whatever questions you have surrounding this fast idle problem you're having, please use the thread that i left open on the subject. if you have a new issue, then you can make a new thread.

thank you.

 

Okay and when I adjusted the fast idle screw I got the idle down to 1k idling good then as soon as I hit the gas to rev it it went back up idling rougher than before so I put it back in the position it was thanks for the replys

 

When zee engine is cold the idle rests at about 1500 rpm until the engine slowly heats up and the idle slowly drops til it reaches 750 rpm. The thing is the metal rod which rests against the upside down screw should extend as the car warms up. When this happens the rod pushes down on the screw which then closes the throttle plate which lowers the idle. So, the rod needs to extend as the car warms up and if it doesn't then the system is not working properly. You can't just adjust the screw to lower the idle and expect the idle to be corrected just like that.

On a turbo the BAC has an idle adjust screw to fine tune it. And the initial set coupler needs to be grounded when doing this. The idle should always be set w/the engine as hot as it can possibly get and not close to it. So, were talking about a twenty minute drive at least to do this. And w/the engine fully hot and the key to on the Green/Red wire of the TPS should read 1 volt. To set the TPS to 1 volt using the TPS adjustment (not BAC screw) the idle speed needs to be under 1100 rpm (and initial coupler grounded.

 

My bac is removed and blocked off I will check my tps voltage tomorrow when I adjust the screw there is no change in idle but I did try another tps and it was the same exact thing

 

The BAC is a very important item as it is supposed to keep the idle steady at 750 rpm when the engine is under load such as the heater/fan/AC is on or the lights etc. Also, the coolant hose from the water pump would pass through the BAC to the thermovalve (remember the fast idle cam mechanism).

 

Okay also ac and powered steeing are deleted. So I should look into getting a bac?

 

Yes.

 

I just found out my leading coils are not getting any spark from the coil it has power to the plug so the car is running on trailing coil what can this be a bad ecu?

 

The coil gets it ground from being bolted to the fender so the contact point between the fender and coil bracket might need to cleaned up. The coil/igniter might also be bad. The plugs and or wires might be bad as well.

The plug has a Green/Yellow wire. Unplug this plug and measure the voltage of the G/Y wire w/key to on as the main pulley is rotated. The rotation of the alternator pulley will rotate the main pulley. The voltage alternates between two values with one being o volts and the other 5 volts. This triggers the coil to fire. If you have this trigger then there is no problem with the ECU. The two voltage values alternate from one value that shows up on the voltage meter for a period of time and then all of a sudden the value changes to the other value for the briefest of time only to revert back to the original value.

 

Okay I will check out the voltage to the wire in the morning so when I crank the engine it should send pulses of 5v ?

 

Rotate the engine by hand.

 

I am rotating and there is 11.78 on b/y wire the g/y is showing 0.01 in using a multi netter set to 20 v

 

You have to rotate the main pulley a fair amount as in at least one full revolution and you also need to pay close attention to the G/Y wire voltage as it will change in value for a split second if that.

 

What should the green wire read when rotating?

 

I'm pretty sure this was covered in post #11.

 

So I cut the wire it was reading 5v I re did wiring and no voltage I think the plastic connector is bad I will be swaping it tomorrow and let you know it runs on one rotor with the trailing coils firing. I can't wait to have her up and running correctly. I appreciate the help I'm new to rotarys a pain but I love them.

 

I can't find a short in the wire and it's no sending no power what can it be ?

 

And you're testing the Green/Yellow w/key to on as the main pulley is rotated? Also, are you doing the test by yourself?

 

I tested by myself I turned it with the multimeter hooked up even tried taking fuel pump fues out and I had the multimeter laying on the front windshield and cranked it and nothing

 

Is the plug to the coil housing the G/Y wire plugged or unplugged when testing as it is easier to do w/it unplugged. Also, you could pull the CAS an spin it w/key to on and regardless of how slow you spin it for it to rotate one full revolution you would get four 0 to 5 volt pulses.

 

Unplugged and it showed no pulses could timing be off?

 

That might be possible I guess or the CAS is not connected properly although you state that the trailing works so that is a head scratcher. Maybe you could unplug the CAS and replug it in.

The G/Y wire runs to pin 1V of the ECU so you might want to make sure it is snug in the plug housing. And when you rotate the main pulley are you using the alternator pulley to do so, and if so, are you sure the main pulley is rotating or is it possible that the belt is slipping and therefor the pulley is not rotating.

 

Which fuse did you pull as in what is its specific name. If you pulled the wrong fuse it would prevent the G/Y wire from doing what it is supposed to.