Hey need some help with my 88 RX-7 SE. 143k miles, original engine

I had a fuel leak at my PD, so i did the banjo bolt replacement. While i had the engine apart, I removed the rats nest, all emissions, and the OMP. Replaced the oil injectors with bolts of the same size.

I put it all backtogether, mixed some premix for the gas tank, and tried starting it yesterday. It started right up first try for about a second then died.

Tried to start it again, and the engine sounded different, like it had no compression or was flooded. so i removed the spark plugs, turned it over, and it was making some weird uneven noises. Put some oil in the spark plug holes, reinstalled spark plugs, and tried starting again.

It roared to life again for a second but died. Engine still sounds like no compression or flooded when turning over. Did a compression test and it was barely registering on the gauge on both rotors, all faces.

I am 98% sure i didnt drop anything into the intake. Anybody know what may have happened?? The car ran fine before??

 

Flooding causes low compression, right? Could i have hooked up the fuel pressure regulator vaccuum line wrong? Rigth now its going to the nipple under the BAC

 

im pretty sure you need a aftermarket ecu...at least for the fd you do. What ecu are you running?

 

The FPR is going to be at atmospheric pressure during starting. There isn't going to be enough vacuum created by a cranking over engine to do squat. It isn't a FPR problem.

Are you SURE the afm is connected electricaly? A RX will start with the afm disconnected but will not continue to run. The fuel mixture on starting is dependent on a Fuel Map in the ECU. Once started though, the afm gives the ECU the fuel mixture to keep it running.

The Start Fuel Map is out of the picture the moment you let the key go from start to on.

 

well i just did the hardcore unflooding procedure, removed all 4 plugs, turned over w/o EGI comp fuse for 20+ seconds with throttle to the floor, put a little 2 stroke oil in the plug holes and tried to start her with no luck. Compression sounded better, and she caught a few turns but never started. AFM is still connected like before.

after taking the plugs out again, they were wet with oil and fuel, so i know its getting fuel, definately getting spark, so i guess compression is missing?

I just dont understand how it could have lost all compression. It drove fine before the rats nest removal. I guess ill try to unflood a few more times before pulling the engine

 

Got it to start for 5 seconds yesterday, at WOT at about 2k rpm. Im thinking major vacuum leak or lost compression

 

Major vacuum leak is quite possible. Have you left any of the passages under the dynamic chamber open (driver's side, near the assorted bypass solenoids)?

With the plugs pulled, turning it over, do you at least get even pulses? If it's flooded, you're not going to get good compression (and it sounds like it's pretty well flooded).

You can also try using the fuel pump relay under the dash as a fuel cut switch (if you don't have one) - pull the relay and crank it, it'll often fire for a bit with the fuel in the chambers/runners, and dry stuff out. If you're quick, you can click the relay back in while it's running off the existing fuel, and have it run.

Oh! When you did the rat's nest removal, what did you do for fuel lines? The symptoms you're describing (starts, runs for a second or two, dies) can also be caused by having the fuel lines reversed. I don't remember which goes where, but if you disconnected the fuel lines and replaced them, you could have them backwards.

-=Russ=-

 

The fuel lines go from fuel filter -> PD banjo bolt -> lower fuel rail -> upper fuel rail -> FPR -> fuel return line.

The only vacuum lines i kept are:
FPR to nipple under BAC
Primary injector air bleed to middle of the 3 nipples on the non-firewall side of the UIM

The one time it ran for 5 seconds, i had the fpr vacuum line open to air. I just realized I forgot to cap the nipple i originally had it on. That would explain the crappy running- will try again today after work

thanks for teh tips

 

Finally got it started, it must have just been flooded to hell

Thanks for the help!