Hi Guys. My FD will not start, checked all the usual stuff (vacume pipes, plugs, spark & fuel) then noticed when I am cranking the engine the air pump is not engaging. Should it engage from start up? If it should and mine is not doing so could this contribute to non start?

Cheers

 

No, has nothing to do with start, more with idle, but it might point to the fact that some fuses / relays are blown, the airpump relays are in that front row of relays by the latch to the hood... if you can't see them on a stock 7 take off the air shroud from the IC inlet to the Airbox....

 

Check compression, I think most fd owners shy away from this out of fear. If you have spark and fuel you only need one other thing to start. If you dont know how to conduct a compression check, go to RotaryResurrection.com. Even if compression is good that is one thing you can rule out.

 

I would defer to someone else with specific knowledge of this, but I believe the clutch to the air pump (just as with the AC compressor) does not engage during start-up. It does not engage until the enging is actually running. Takes a load off the starter.

To your real question, there is something else wrong preventing start-up. You may want to give a little more information. For example, how was the car operating leading up to the non-start situation, how many miles are on the motor, are there any special mods we should know about, have you checked the condition of the injectors (leaky injectors cause poor compression), etc.

 

Hi Guys, thanks for replies so far. I jumped the air pump relay and cranked the car and it engaged the air pump ok so that seems fine. Have checked all the vacume lines that I could see/get at on was faulty so have replaced it but have seen one looks as if it is missing from one of the pipes in the 'rat's nest' so will have to take off the throttle body to inspect.

In answer to how the car was running prior to this problem it was runing fine no problems what so ever apart from ticking over a bit high (about 1250RPM. Problem started when it cut out a couple of times when at junctions but restarted ok then cut out and would'nt restart, then managed to get it restarted but knew it would stall if I let the revs die. Managed to drive it a short distance home and as soon as I let the revs drop it stalled and has not started since. Had it to Mazda dealer who checked it and no faults showing (they wanted about $320 to put 2 new spark plugs in it to SEE if it would start - I said NO and towed the car home) A friend has a car repair business and carried out compression check and goiung by what I read on 'RotaryResurrection.com' compression seems fine. Car cranks and sometimes almost fires up - no further forward as yet!!!

 

It may be low compression. You said you checked it, but unless you have a rotary engine compression tester you can toss out your previous readings.
A quick way to tell if your compression is low is to drain a cap full of ATF down each of the two intake nipples on the upper manifold (one is for the ABV, and the other is capped unless you have a boost gauge plumbed). This will give you momentary compression and the car will start if all else is good.
Your cutting out is a bad sign of something wrong. It may be compression, it may be very worn out spark plugs, or it could be bad coils. Who knows, but one thing is for sure, you are going to be pulling your hair out if you have to do this your self. I hope your friend is skillful.

 

Some of the metal pipes under the intake manifold are not used so don't freak out and spend all the time pulling all that stuff out. You can use a regular compression tester just take out the bleed valve and just keep an eye out on the needle, it will work. I had a faulty fuel pump cause a similar problem. I'd say start with all the easy stuff first. Make sure your getting fuel, spark, new plugs, do as what spooledUP7 says and try the ATF. Think about all the easy stuff first. I have always fixed a problem starting with the basics. If this all fails, good luck, cause then your digging in to Rotary fun. Also, use this site, do lots of searches. Because of this site I have been able to fix every problem I've had so far. Kent.

 

Thanks guys, will give it a go & keep you posted.

 

Hi, sorry to be thick but what is ATF (I take it it is a light oil; is this a brand name) ? It may go by some other name over here !

 

Automatic Transmission Fluid (ATF)