Ive been trying to chase down why my car won't stay running.it starts hard when cold, then will run for 15-20 minutes, then stall. If I give it gas it'll rev up, then choke out and stall. No codes. It was suggested I check injector wiring. So after removing all of the upper intake manifold, I made 2 discoveries. One of my hard plastic omp lines is broken. Secondly (and I don't know if this is normal) my fuel injectors are really loose. They can just spin and turn freely in the ports. It is also wet with fuel around them. The omp line I'm not too worried about because I am running pre mix, but is it creating a vacuum leak? Are the injectors supposed to be tightened down?

 

Uh, buddy, you sort of need those OMP lines in place.

 

It's only one broken line, the rest are in tact. I'm also running premix. What will happen? Is that why I'm stalling?

 

Premix will help but not if the damage is already done from the lack of oil cooling and lubricating the side seals. Leaking fuel injectors are a good way to burn your car to the ground an anything around it.

 

The OMP needs the pressure to overcome engine compression. One line out means that your pressure is way low and you're not feeding much if any oil to the engine. Is it hard to start cold?

Premix even at 1 oz/gal (track only) is likely not enough - although I'll defer to those experts to how much the OMP is metering.

from Racing Beat's site:
Metering Oil Pump Rates
The metering oil pump found on all 1989-95 RX-7s is an electronic unit that cannot be externally adjusted to change oil flow delivery; however, if you require additional oil flow, you can completely remove this electronic unit and fabricate a cover plate with an adjustment screw mounted in it to allow manual adjustment of the oil flow. This cover plate replaces the electronic control.

The metering rates for stock engines vary, so consult an appropriate shop manual for your car’s specifications. In normally aspirated racing vehicles we use either a setting of 5cc/5minutes (total flow - 2,000 RPM, warm engine, arm in the "full throttle" position) on the metering oil pump or premix 3.5 oz of good quality synthetic oil (preferably 2-stroke motorcycle "oil injection" oil) to 5 gallons of fuel. The requirement for turbo engines in racing is high enough that use of a metering oil pump is impractical. Therefore, we premix up to 22 oz of oil to 5 gallons of fuel in a 600 HP 2-rotor. If you are not pressing your engine this hard, you can use proportionally less oil.

 

What's the best way to trace the fuel leak? Just turn ignition on and see where it's coming from?

 

Holy **** man, don't be like the miata guy who burned down his house.

 

Engine is hard to start cold, takes a couples minutes of cranking. Then it will idle for 20 mins and stall. Haven't driven the car, it dies when given gas. The motor is a fresh rebuild, just put in this august, have been trying to figure out issues since. I have 1.5 ounces of idemitsu per 1 gallon of gas in it now. You think my whole issue might be that one omp line? Hopefully haven't toasted the new seals already..

 

Lol, I meant without spark hooked up, to get the fuel to prime..

 

Dude. I think the engine's done. You NEED the OMP unless you happen to have a SOHN kit replacing it or you have manual oiling going to the engine in some other way. So... You've got fuel leaking everywhere, which means that even less of the premixing lubricant you're putting into the engine is getting in there.

 

Minimal fuel leaking, it's not dripping or making a puddle. I don't smell gas unless I'm right in the engine bay. It is wet, but not soaked. But I hear what your saying. So you think it's a lost cause? It still will run, does not over heat, it sounds very smooth while running (until gas is applied), there is no crunching or knocking or mayhem whatsoever. Just stalls.

 

Are the fuel injectors correctly placed? Since you just had the engine out, it's possible they got mixed up which would create unpredictable symptoms. Being wet with fuel around them is also not a great sign, and since fuel doesn't flow up, look for a leak above the injector hole. Is the fuel rail installed tight?

Also being a fresh rebuilt, if it hasn't been driven at all it's probably not broken in yet, which means it will have low compression, which will improve as it breaks-in.

Obviously the OMP line needs to be replaced though.

 

Upon further investigation, it's not fuel that leaked, it is oil from the broken omp line. I ordered and will be installing a new omp vacuum block and lines (spider thingy). This may have been my whole issue, the vacuum leak and compression lost from improper lubrication may be the culprit.