Hey Guys,

I'm new to this rotary world. I'm a 20 year old college student who purchased a 93 Mazda Rx7 about a year ago. It has always been my dream car and I knew it was going to be a headache to learn the ropes but I was willing to give it a shot as I have always wanted this car. Anyways about a week ago I started to have issues with the car not turning on. It is cranking, but it will not actually catch on. I rebuilt the engine last year almost immediately after I bought it (was not running). And since then have had a ton of little issues that have been ironed out for the most part. Right now, well before this issue, the car was running but I did not take it out because my turbos are leaky. I plan to fix them soon, but I have always wanted to do a single turbo conversion so i'm just saving up the money for that. Anyways I would still occasionally turn on the car rev it a little and let it idle. After about 30-45 min I would then turn it off. Anyways one day, a little before the thanksgiving the car never turned on. After a couple of tries, it did manage to turn on but quickly turned off on me. I left it the rest of the day and came back the next day. The car turned on the next morning, I stayed in it for about 5 minutes to make sure it would not turn off and as soon as I thought I was in the clear, I enter my garage and the car abruptly turned off. Since then it has not started again, it cranks but wont start. I was told I possibly flooded the car because I would turn off the engine without letting it properly heat up. Thus I did a de-flooding procedure the weekend after thanksgiving. My steps consisted of:
1. Unplugged the 30A EGI fuse
2. Removed my spark plugs
- I was told if the engine was flooded I would see a little bit of fuel drip out as soon as I took them out and I would also be able to smell the fuel, neither were present
- I got new spark plugs (surface gap NGK) when the engine was rebuilt (it now has probably around 500 miles)
- The spark plugs were somewhat damp, but more importantly the surface was black, I assume from carbon build up. I then proceeded to clean them with carb cleaner, and lightly sanded it down with a relatively soft sand paper
- Then with the clutch and throttle fully depressed I cranked the engine for about 10-20 seconds. I did this 5 times.
- I then plugged everything back again and.. no luck it would not turn on. I was told it might take a couple of tries so I did this process one more time and it once again did not work at this point I was fairly convinced the engine was not flooded. Could just be that I did not do the procedure correctly

So now that I told u guys my de-flooding procedure, I'm back at square one trying to figure out the issue. Another possibility is the ECU. The car still has its stock ECU. Keep in mind that the car is almost completely stock with a few exceptions, and the previous owners put a little more than 80,000 miles on it. I also took the car to a rotary mechanic near my house about 3-4 months ago because the car was not accelerating properly. It would hesitate and feel like it would pull you back. The problem turned out to be that the fuel pressure was lower than it was supposed to be. The mechanics put new wires leading towards the fuel pump that fixed the problem.

Anyways sorry for this suuuper long post, but this issue is really bothering me. I have final exams coming up and would like to get an idea on what I have to check before I start studying hardcore for them. Any help would greatly be appreciated guys

 

I had similar issues when I first completed my rebuild. Start by putting in a new set of plugs.

Sometimes they just foul up and stop working, even if you try and clean them up.

 

My thought exactly - you never did run it hard enough to burn carbon, etc., off the plugs. So fouling is very likely.

Sometimes you can clean up fouled plugs, sometimes not. Better as Axton says to get a new set.

 

Great, I'll order a new set soon. Hopefully thats it and not something with my fuel pump or ECU. My father thinks the car is not sending fuel, but the fuel pump is new, and the mechanics literally just fixed my fuel pressure levels last time I took it. Is there a way to know if my ECU is working properly? Thanks for the help

 

The Factory ECU seems to be pretty robust.

Not completely sure what the failure signs would be, but I would assume you wouldn't hear any solenoids activating at key on and wouldn't get any fuel in the engine (or flooding for that matter) as it controls the injectors.

I'd recommend if you can afford to, get 2 sets of plugs so you have a spare set sitting on the shelf when needed.

 

I had a similar situation. I order new plugs but while waiting for them to get in I soaked my old plugs in gasoline and cleaned them up. I cleaned them just enough to get the car running again but it ran much better with the new plugs. When I wanted to make sure fuel was getting to the rail I popped off the fuel line and put it in a water bottle then primed the pump. It's a pretty basic test but it helped me fix my fuel pump grounds

 

Is the check engine light on? have you checked for codes?

 

Check the compression

 

Yea the Check Engine light is on. my mechanic said it was because of the EGR valve, but it is absolutely possible that the ECU has gone wrong since then . I'm not sure how to check the codes but I'll figure it out and check em soon. Even if ECU is not the problem I would just like that peace of mind.

 

Yea thats what I'm going to end up doing. Even if my spark plugs are functional right now I'm going to need to change them eventually in the future. Hopefully that does the trick.

 

do a search on checking codes, it's not too hard. You just have to watch the check engine light blink. The main thing you want to look for is if anything is unplugged or shorted that could affect engine operation, and the check engine codes will tell you that.

 

Also, once flooded, the fuel may have cleared the surface oil and so compression may not build up in the motor. if this is so, you can try to pour automatic transmission oil (just little bit, not too much) through the spark holes, clear/new spark plugs and try again.

 

It may be a dumb question but are you 100% certain you have gas and did not run out? The fuel level gauges on these guys are getting worse and worse the older they get (the contacts on the level float sensor need cleaning). Alot of FD owners I know have had fuel shortage issues at some point or another and thought it was a much more complicated issue than it really ended up being.

 

Well the issue started when I was low on gas. I tried to turn it on one day and noticed that my gauges read almost empty. When the car was not turning on I thought that was the problem. So I added gas until the gauges read half full, but still had no luck.

 

I would take a close look at the coil. You need three things for combustion, fuel, heat (spark), and air. As coils heat up, they can fail. If you have an old timing light, you can use this to check for a spark., or pull a plug wire off and hold it close to the plug, or a ground, and listen or look for a spark. ( keep fuel away from this spark). I experienced this on an old chevy that would run when cold, but later backfire & stop running. When I touched the coil after it quit, the coil almost burned my hand. After R&R the coil and the chevy started right up. Also check for power on the + side of the coil.