I've created a new post because I have two problems in the same general area (of the car) that may be linked to one another. I've searched "car won't start" on the forums and wasn't seeing anything worth looking into any further.

The car is a 1990 RX-7 GXL, N/A. I recently bought a new battery and battery terminals.

Problem #1
- When I first start my car on a beginning of a new day, I turn the ignition to ON. The voltage reads the middle mark, ≥ 12v.
- I start the engine and it then reads the mark above the middle, ≤ 14v. I let my car reach normal operating temp for obvious reasons (if this helps, the coolant needs to be bled).
- I shut off the engine, but if I were to try and start it again (whether it be right away, 30 mins later, or a hour), it won't start (definitely not due to flooding).

It will read ≥ 12v as usual, but if I crank the engine for < 5 secs, it won't turn over. It will actually drop to ≤ 10v while I'm cranking it, thus not starting.

Problem #2
When the car does start, it will kick into high idle at 3000 RPM but drastically drop to the point where it looks like the engine is going to die down. I have to keep the clutch depressed for a bit, in order for the RPM to stay at that 3000 and continue running. Then it will drop to 2000, 1500, etc. Once the car "settles" and can run on idle, the RPM will rise once more from 1000, 1500, etc. I didn't pay close attention to this part, but it will usually rise and plateau at 2000 - 3000.

For the high idle I've seen the fix on it in the FAQs, but the issue I'm trying to address there is why the engine is about to suddenly die down after starting, unless I keep the clutch depressed.

To be honest, I didn't just let it do it's thing and see if it would have died down on me after starting. When the RPM was dropping the sound starting to faint, and it looked like the engine becoming "slow". I pressed the clutch and it seemed to keep it running and hit normal idle.


..So that being said, can these two issues be possibly linked to each other? For problem #1, I've already got the parts for the battery. What should I be checking next? Alternator, wiring, spark plug, etc? If so, is there any sequential order that I should follow it in? If it helps even more, I can record a video for a more visual aid.

 

1) If the voltage reads ~14v with the engine running, your alternator is fine. If the starter will spin the engine every time, you also do not have a battery or battery cable issue unless it cranks slower than normal. Battery voltage will drop during cranking due to the huge current draw the starter motor has. That's normal.

If I read this correctly, you have to let the engine crank for 5+ seconds before it starts?

2) 3K RPM is normal initially as part of the accelerated warm-up system. It should settle to 1500 RPM soon after, and then gradually go down to 7-800 RPM as the coolant temp rises. The thermowax plunger on the throttle body allows a cam to move, which adjusts the throttle plate position.

Given the erratic high/low idle speed and potential stalling, I would say a vacuum leak or metered air leak is the most likely cause. Depending on the size, the ECU can attempt to fight it by adjusting the mixture and adding/reducing air via the BAC valve. If it smooths out once the engine warms, it may settle at a higher RPM due to increased airflow from the leak point.

 

Problem 1 sounds like the starter solenoid is failing thus the starter should be rebuilt or replaced
Problem 2 sounds normal my 3rd gen does the same with a PFC it looks like it's gonna die but will catch itself without touching the throttle and bounce around the rpm before settling to a nice purr

 

I meant that after I shut the engine off and try to start it up again, I'll let it crank for no more than 5 seconds, but it won't turn over. It only seems to run once a day.

It sucks because what if I needed to buy groceries. I leave for a few minutes and then when I head back to the parking lot, it won't start. It's like it needs a few hours (or even a day) to "charge up".


I've never seen my 7 idle at 7-800 RPM. While it's reaching normal operating temp, it fluctuates. Then when it reaches normal operating temperature, it'll idle at 2500-3000.


...I'll check for these issues tomorrow and keep posted. I'll see if that's really what I'm seeing.

 

I'll check it out tomorrow just to be sure!

 

A bad starter/starter solenoid would give intermittent cranking. ie it spins sometimes, but not others. The problem described does not appear to fit that criteria.

In that case, it's common hot-start problems. With age the engine loses a little compression. Couple that with Mazda's overly rich start map under warm-hot conditions, and you get problems with flooding. The fix is a programmble ECU with start map control, but the common cheap work-around is a fuel cut switch to cut power to the fuel pump. If it floods, you turn the pump off and crank the engine. Turn the pump back on when it sounds like it's catching. If you have an S5, you actually have a built in fuel cut switch. Press the throttle all the way to the floor and the ECU will cut all fuel delivery. Crank the engine to clear excess fuel, then ease up on the throttle and it should start.

 

Is this the trick that involves removing the EGI fuse?

 

Flooring the gas pedal on start up cuts fuel on an S5.
An S4 will just get full throttle.
Removing the fuse cuts all fuel,Until you put the fuse back in.

 

Yes, on an S4 you have to remove the EGI fuse to get the same effect. Not as easy to use.

 

I can't see it being a flooding issue though. I tried it once when that issue I stated first happened. No luck. I did it about 6x's. Anything more would be pretty overboard if you ask me; especially if I have to do it out in public.

I'll check again, just to be sure! Although I'm empty on gas and the lid won't open, gotta get that fixed first

 

I think you better open up your wallet and toss some gas in your car first!

 

No master with my 7 or anything but I know what you mean on cranking and not starting, I believe it's all in how u turn off the car. If ever you turn off the car while its warming up, be ready to crank it for a while or pull fuses or spark plugs. (Or in your case, since it's idling at 2500 to 3000) it's almost like the same thing with the accelerated warm up system I just make sure I give my car a minute warm down after a drive and I haven't had that problem since. Also, does you hear a "click" when you turn the ignition? If you dont i believe it signals a bad solenoid switch Hope this helps even a little bit

 

i agree with hairball

 

I never turn off the car while it's warming up. After it's warmed up, I usually give it a good drive around the block, then it's parked back on my driveway.

I'm not too sure. I'll check on it ASAP. Light snow is coming back, damn it, I can't do anything in our current weather.

 

No clicking. The engine cranks just fine (still won't start a second running) and I heard no click.

I'll be replacing the spark plugs and swapping out for a better alternator this week, hopefully. If all else fails, well, at least I installed new parts and narrowed my problem down more to other reasons.

 

How about two seconds at most of starter spray in the intake duct w/the fuel pump disabled and see if the car starts. If it does you know you have spark and can narrow down the problem to being fuel related perhaps.

 

I agree, no need to blow so much money on a new alternator and plugs.

Besides, from what you were saying earlier, your voltages seem normal.

And the fact that it doesn't turn on the 2nd time strongly leads me to believe it is an issue with flooding.

When you turn off the car, what is the RPM?

EDIT: And the click will be heard if you just turn the ignition to ON without cranking, but most likely if it is cranking, i don't think its the solenoid either.

 

If the starter spins every time, it is not a battery, battery cable, alternator, starter or starter solenoid problem.

If the engine cranks but does not start, the problem can only be air, fuel or spark related.

 

I heard the clicking noise, so that narrows it down more. If it is flooding, I might need to replace the spark plugs, because I did the EGI trick and it doesn't work.

At least the issue is getting more narrowed down to one answer

 

That'll be the next task I'll try tomorrow!

So just to be sure... I remove the EGI, crank the car with the clutch depressed, but... As for the starter fluid. Is it a two man job? Do I need someone to be spraying it while I crank at the same time?

 

Spay and then start. Requires just one set of hands.

 

Thanks! I haven't used it before, so I wouldn't have known.

 

Just a quick question... Where is the intake duct on the S5? I looked in the manual and I saw nothing similar to what was in my engine bay. Nothing is after marketed either.

 

Here's something new... She wouldn't seem to start up with the clutch alone, so I did clutch+accel and it managed to start. Again, the RPM was about to drastically drop as I was releasing the clutch (literally, it was going to shut down), so I kept tapping the accel until it managed to idle.

I shut her down after I let it reach normal operating temp. I couldn't idle too longer after that (coolant needed to be bled). I took a washroom break and once I got back to start her up a second time, she wouldn't start.

I did the EGI trick 6x's, no luck. I even did 2 seconds of quick start fluid with the EGI removed and it still would not turn over.

Idk what it is.... It cranks, I hear the click when I turn it to ON, the battery reads 12v just before I crank.


Added: If this helps, yesterday and last Saturday(?), it would not start either. It would crank, then you'd hear the engine about to run for a second, then POOP! The car just died. I also noticed smoke coming from the exhaust. Not your typically factory looking puffy type of smoke, that really vivid white type when you smoke. As for exhaust popping, I'm not too sure. If anything, yes, since I saw the smoke.

 

It is all still guessing until you test a few things. Next time it wont start you should pull a spark plug after the first attempt at cranking and see if it wet with fuel. Also I would go to an auto store and get an inline spark tester, very inexpensive less than $25, and confirm spark. If neither of those are the culprit I would move on to checking fuel pressure and compression test. There are a few things that could be.

1. Flooding due to ECU tuning, bad IAT sensor, bad CLT sensor etc.
2. Poor compression
3. No spark. Under hood temps can heat soak electronics such as the coil or igniter however I would find this less likely because you would most often have the car die while driving as well.
4. Fuel pump. Often a fuel pump can have a bad spot in the electric motor which causes it to not start turning if stopped, however will continue running once it has already started. Again this is a problem often seen once the pump is warm. I saw you stated the car was low on gas, a low fuel tank level is bad for fuel pumps because in most systems the fuel in the tank surrounding the pump acts as coolant.

I hope something here helps. No matter what the cause if you are going to be working on the car yourself I would invest in an inexpensive fuel pressure gauge, compression tester, and an inline spark tester. All can be had for around $100 total and can save you quite a bit of money vs guessing.