have an issue, big issue. I have a 1993 rx7 w/ a haltech e6x. Streetport, stock primaries, 1600 secondaries, aeromotive 1000 pump, ls1 coils, & so on. The problem is the car has a real hard time starting, right now it wont start at all. Injector duty cylce jumps around from 3-6% on occassion playing with the throttle, the duty will go significantly higher. All the coils are firing OK, the fuel system has plenty of fuel returning back to the tank, pressure on start is approx. 45 PSI. The engine turns freely, almost acts like it's flooded. Voltage is between 12 - 12.5, while cranking is around 9 - 10 Volts. Once in while I can get it started, when it runs it runs real strong, the car made 465 RWHP at 16 PSI @ Danzio Performance. It runs real good & then all of a sudden, at a stop sign it'll die & wont start back up. I ran a compression check, it was fine. The coils have juice while cranking. There is fuel running while cranking. I took out the injectors, all 4 of them & check for leakage, they were fine. I cleaned them up & reinstalled them. I replaced all the spark plugs, that wasn't it. I'm stumped, please help with ideas. Please forward to anyone that you think might know what else to try.

Thanks in advance

 

you said it wont start... Is it not starting at all after the initial drop at the stop sign? Or will it not STAY running after you crank it?

 

Yeah we finally got it started, ran a little rough. I had to keep the RPM's up so it would'nt die. I got it in the driveway & let it idle down, it died. It has'nt started good since. We had running for a little bit, but it was real rough & died.

 

sounds blown

 

I have a hard time believing it's blown. The guy that tuned it, said in order to check the compression leave the top plug in & put the guage in the bottom hole. If the compression is between 60 - 90 PSI it isn't blown. The front hole averaged 65PSI & the rear hole averaged 75PSI. I also read somewhere that if there was a blown seal present there would be at least 20 PSI difference between the front & rear housing.

 

Keep in mind I'm a newb and don't know **** from Hylomar, but let's think it through. In order to have ignitiion you need: (1) spark (which you have): (2) fuel (which you appear to have): (3) compression (which you appear to have).

So what's left to check for? How about oxygen? Got anything between the intake and manifold that might be malfunctioning? and one last wild shot, how about exhaust? Seems like a clogged cat could cause some of the symptoms you are reporting.

There's one last element to check, but you are on your own here: maybe your ecu?

Now, I'll go back to my newb nest and continue studying my service manual.

 

check your grounds

 

Twitch 1 is actually a friend of mine helping me out. I just got registered on this site. We had the intake off, everything looked fine. The cat has been removed, before the tune. We tried grounding the block to the chassis separate, also. No dice. If it was the ECU, does anyone have a spare E6X laying around?

 

Would you happen to know what page in the FSM that shows where the main grounds are at
Thanks for all the info guys

 

OK, As we mentioned before, the motor has been streetported. In the beginning I had the following heat range plugs; Directly back from from tuner I had 8's leading, 9's trailing. The problem was a slight upper RPM miss that consistantly got worse. I swapped out those plugs with HKS 525's & 55's (10 leading, 11.5 trailing). The car ran good for a while (maybe ten miles), no miss in the upper RPM. But then I developed my starting issue. Today I swapped out the HKS plugs for stock plugs (7 leading, 9 trailing). My upper RPM miss is back, but the car started right away & did'nt die on me. I drove around a couple of miles after warm up, got on it before boost ran good, after boost miss at 6000 RPM's. Pulled it back into my garage, now it has a hard time starting again. I noticed some oil on the plugs, maybe there is too much oil in the fuel causing the plugs to foul (I mix my oil & fuel manually [1 ounce per gallon]). Maybe the 7's are good for leading, but I need 10 or 11.5's in trailing. I've never heard of anyone having this issue. AT LEAST I KNOW THE MOTOR ISN'T BLOWN!

 

Just in case anyone sees this thread-THE MOTOR WAS BLOWN! One of the seals was blown causing all these freaky problems. Dave down @ speedmachineperformance helped me out. The rebuild was expensive, but worth it. He did a few more tricks that will hopefully keep the seals in it this time. So far so good. The car is pretty quick . So if you are in doubt, it is probably a seal or two. But hey, at least I learned quite a bit more about rotaries in the process .
Thanks for the help!

 

lol, the last two posts are pretty funny.

AT LEAST I KNOW THE MOTOR ISN'T BLOWN!

THE MOTOR WAS BLOWN!

 

dave gibson does awesome work

 

Ain't those # too low for compression? I though everything under 75 psi is ? I could be wrong but just wondering.

 

The mazda specs are 75psi and lower require a rebuild.