Before you read, I plan on compression testing it, I'm waiting to meet up with a friend so I can borrow his compression test kit.

I have a 6 port bridge that I had build by a local rotary enthusiast/builder, I have RA Classic apex seals, new apex seal springs, Atkins solid corner seals, fd corner seal springs, used side seals and used side seal springs (he said he doesn't even replace the side seals in his own engines) and used housings (with roughly 90k miles on them and looked amazing from what I could tell and he agreed)

Issue: I've had many issues and have spent many hours and have gained many gray hairs trying to get it to start and stay running, it's a fresh rebuild but the longest I've been able to keep it running is 30 seconds, (I originally assumed it was a software issue due to the fact I also installed ms3-pro in the car). When cranking it will bounce between 248-252 rpm, when I pour oil down the intake it will crank at 250+ and sometimes when it wants to turn over I can watch the rpms pass 300, when the car starts it doesn't sound like its missing, but it will slowly lose rpm (regardless how much I fight it with the throttle) until it stalls out. I've come to the conclusion it's low on compression because the moment the oil shoots out the exhaust it stalls out (then proceeds to crank like there isn't any oil left in the chambers). At once point we've even pulled it with a car and got it to start up (took going 20 in 1st year for it to finally fire up just for it to stall out...)

Anyone have this issue?
If so how did you overcome this headache?

 

Are you using a preloaded stock map? Or one you started out with yourself?

Rebuilt engines having low compression is common until they get broke in, but i agree it sounds like when you dump oil in its bumping the compression up enough to start it then burns it off

 

I'm using a mix between someone's bridgeport map, (he gave it to me thru rx7 club and is used on a running car) and aaroncakes base map, running the bridged VE and ignition table, everything else is aaroncake

 

Any recommendations on how to break it in an easier way? I'm growing very tired of this never ending process I'm attempting

 

Low compression would make it hard to start but should be ok to keep running... That sounds more like not enough fuel try bumping it up. Also double check whatever you are using for crank signal, don't know the specifics of that ECU.

 

AFRs read between 12 and 13, so I don't think fuel is an issue, and I've had several people look over everything and no one can find any tune/wiring errors...

 

Check compression?

Also could be dying out after post start enrichment stops adding fuel

 

If you are burning oil will affect the afr. Like post above said sounds like running on start fuel and not enough in running portion.

 

We originally thought it was a fuek issue but we upped the ASE and it had the same symptoms like nothing was changed...

 

If you suspect the compression is low, why haven't you checked it yet?

 

Read original post... First statement...

 

Thats stupid. Compression testers are only 20 bucks at oreilly. Go buy one.

 

Picking one up tomorrow, what should numbers read (typical numbers for a fresh rebuild with used housings)

 

80-85 depending on crank speed

 

And what are decent broken in numbers? This is my first real rotary build (last engine was a 12a and it blew after a year due to it being abused for years from the previous owners)

 

anything over 110 is outstanding IMO.

 

check your fuel supply and return lines are not hooked up backwards....

 

I dont think it would even start if they were backwards.

Also, after 30 seconds, try to keep it running with starter fluid. If it stays running, you know you have a fuel problem.

 

Well it will start off the oil and starter fluid. Def a fuel issue first place to check is fuel supply ..right? Do you have a fuel pressure gauge before fuel rails ..hopefully something simple but check basic stuff first after a rebuild its easy to hook something back words or not at all .. Also check your injectors are hooked to proper electrical connectors . The key to trouble shooting is going through and eliminating all the basic stuff first ..but you'll get it rotarys are fun like that ..more time dumping money into them and working on them then actually driving them..

 

sorry for the late response, my app wont allow me to open this thread for some reason?

heres some more history on the processes weve gone through...

we've confirmed timing matches up with the CAS, so timing isn't an issue

checked spark, (spark is brilliantly strong, even when the plugs are soaked in fuel it can spark over the raw fuel without any issue) Yukon Coils over all!

took off the fuel line to see if we were getting fuel, we weren't (brand new walbro 255 took a **** on me, literally had 3-4 mins of run time on it... no clue why but it wouldn't pump) Replaced it with a fuel pump I had laying around from another project (from some late 80s or early 90s EFI ford with a big block) and it flows plenty to run this car according to the specs (brand new pump).

After the fuel pump issue was addressed we decided to test the injectors, we pulled the UIM off and to see if injectors C and D were pulsing, C was a dead injector, replaced it with a used one my friend had laying around and fixed that issue, pulled the primary fuel rail off to see if injectors A and B were pulsing, both were pulsing fine so now all 4 injectors pulse.

The only other issues that could be fuel related is the FPR, or the tune isn't giving enough fuel, (Im going to check for fuel pressure to see if I can find any issues and while Im at it I plan on checking compression as well) we are in the middle of a snow storm so I wont be able to go tinker with it for a few days due to us expecting 8-12 inches of snow in a day here in southern Indiana

 

So I'm over in the MegasSquirt section trying to help you, but then I learn in this thread (a completely different thread somewhere else) that you had a bad injector and a bad fuel pump?

Please keep your information in one thread.