Hey guys, so I have an 87 FC3S single turbo currently in Japan with plans to import and as far as mods it's running a from mount intercoller with a twin plate clutch" super noisy"! And straight pipe exhaust and I just put a brand new set or spark plugs on her a new fuel filter and cleaned the maf sensor. Full cage , gauges and seats, RHD, strut bars front and back and under the car in the back as well. Sooooo..... The problem I'm having is after ot starts it runs fine for a while and slow as me to build boost with no problems! After I drive for a bit and the pressure seems to bleed off or something but I can only apply small gas inputs and continue driving , still drives but anything over a quarter throttle the car literally just cuts out , power is there but it's like the engine just stops and I'm coasting and then I let off throttle and it's back with small iinputs! Any ideas? Open for anything I've done minor searches for boost leaks and leaks in general but nothing! And it runs fun after starts for a bit if I rev it up in rpm's( which I'm thinking is because I build pressure early and that's what allows it to run wth full throttle for a bit but not sure ) and it works fine? Any ideas ????

 

Welcome to my world.. sadly I am having the same freaking issue. I changed all vaccum lines and waste gate lines, and checked the waste gate for any obstruction/stuck open or ping damage. So far I haven't found the fix for it.
My next step is take the ignition harness and inspect for broken wire, then fuel system. I might check my pfc wiring as well.

 

So, you have boost passing 3psi? Can you Rev pass 3500 rpm? Was it tuned ?

 

No j have throttle but no boost after I drive for a bit , it'll build rpm but no boost cause the engine cuts

 

I kkow, I know.. any leaks? Stuff getting heat up and breaking down?

 

I'm lookin right now through my wires and chasing but as far as vaccumm lines go and hoses they aren't leaking

 

Any crack in the mani fold? What about waste gate? I took mines apart and cleaned them and put 9 psi springs in them, ut was a pain to get to them. I will test the car tomorrow and see if keeps doing the same thing.

 

Haven't messed with the waste gate but I have a feeling it needs to be messed with and or replaced but let me know if that's it

 

You need to shoot continuity to your OMP if you still have it. If you are still running the stock computer your car will run fine for like 9 min then go into limp mode. Hence the falling on its face past 30% throttle. If the stepper motor on it is toast then your computer will usually go with it. So i would also crack open the ECU and look for some burn marks.

 

his car is an 87 and runs a Mechanical OMP and has nothing to do with the ECU and therefore will not go into LIMP Mode.

 

Well doesn't hurt to see if I have it this thing has a bunch of mods lol where owould the Omp be ?

 

I put my waste gates back on and cranked the car. It idle nice with out the puff at the start up. Now I am messing with the bov before test drive. It was a pain getting those suckered back in from under the car though.

 

Can you share the plombing, waste gates, is it connected with "T"?, boost controler type and boost source? You could get away with cleaning the wastegates.

 

The OMP is not a part that is usually altered. It is the Oil Metering Pump that injects engine oil intothe engine to lubricate the apex seals. The post regarding it burning out and damaging the ECU is only with respect to model years 89 and onward, which used a computer controlled electric pump. Before 89, the OMP was purely mechanical, and rarely fails. If it has failed, it does not cause the symptoms you are experiencing.

I would not suspect your OMP as the cause of your problems.

EDIT: My first statement is technically incorrect. The pump is often removed. However, if you do not have an OMP in place you should be pre-mixing your fuel. It is on the front of the engine, near the air pump. If your car is consuming oil, as all rotaries should, your oiling system is probably fine.

 

Yah I seem to believe I found the source of the problem and it's my ecu harness the guy prior to me had a SAFC but he hand spliced the wires to the ecu harness and it looks super rough ! So that's all I was able to find that was a rats nest I removed it but there's no telling if my ecu harness is already shot from it. I swapped ecu's to test and it did the same things so the ecu is fine