A coolant system pressure test is in order me thinks.
The issue with this car could be turbo related. Not that turbos on these are easier or cheaper than an engine...
If it was mine, I'd probably go single turbo and simplify. Not to make more power, but to make it more reliable. And, it could be put back to stock.
Mighty Car Mods is restoring an FD right now and they've shown some really cool parts that replace the old plastic bits, along with a single turbo setup
Yes, a coolant system pressure test would be helpful, but it does look like there is some type of leak externally, so it may initially find an external coolant leak. For example, there's a connection when I think hot coolant comes out of the motor and goes to the heater core. That connection looks like a combination of a metal line, plastic fitting, and rubber hose, and looked suspect of actively leaking.
honestly, with the engine turning over by hand easily and making compression sounds and not having coolant in the really wrong places, I am tempted to start doing things like flushing all the old gas and coolant and potentially seeing if it would start.
and for that, I'll need a fresh battery. Size 35 is what this calls for I think, and Costco had them for $125 with 3 year warranty (which feels like a screaming deal in batteries right now). Online they had AGMs for like $180, and I would have bought one of those, but alas they didn't carry those in the store I went to.
here's some shots of just how clean this car is, while I clean out the battery tray.
little bit of battery acid residue, but I was able to vacuum it right up and there doesn't seem to be any rust damage at all here under the battery tray.
Right now, I don't even know how much fuel is in it. So, I'll probably try hooking up the battery and powering up the car to see if I can get a fuel tank reading. Then I might work on pumping out the old fuel and then changing the fuel filter.
honestly, at only 5 years old and probably nice premium fuel, the stuff that's in there might be "ok", and in a challenge car I wouldn't bother, but in this case I think doing it right is worth it.
docwyte said:Mighty Car Mods is restoring an FD right now and they've shown some really cool parts that replace the old plastic bits, along with a single turbo setup
How did I not know this? Where is the algorithm when you need it?
Very cool build. Ive always wanted a rx7 but I have no knowledge of rotary engines. So I look forward to following your build. Thanks for sharing.
Dude, get new fluids in there a battery and try to start it. Either the motor is toast or it isnt. If its toast then you arent going to be more disappointed since you came into this with that in mind. Love the car!
Ok we're back on this case!
first thing I got a new battery and performed my first mod:
the little battery maintenance dongle.
then it was time to add some MMO to the chambers and see what happens.
I pulled the "circuit opening" (fuel pump control) relay and the main efi relay to make sure there was no fuel and no spark, and I cranked the engine for a bit to see if I got oil pressure. I did, so it was time to plug the relays back in...
woohoo!
now, I got lots of smoke probably because of the MMO, but critically, I didn't smell any hints of coolant. Which is another good sign.
i also took this photo while it was idling and I don't see any bubbles, which is really starting to point to a working seal between the combustion chambers and the cooling system. 
Fortunately, as it idled it started to get less smoky. Unfortunately, as it idled it also started to get really rough and uneven, and now it doesn't want to start and idle at all, boo.
i did go ahead and pump out all the old gas, and then I refilled 3 gallons of fresh new with some seafoam for extra lubrication for now. I did this by removing the return line at the tank and letting the fuel pump push all the fuel out. Then I ran it some more after I put the new gas back in, so theoretically the lines are flushed with fresh gas too.
while I was doing that, I saw that a bolt was missing from one of the protective undercovers.
then I noticed that it was just missing, it had been broken off. Ok, so I'll drill it out. Wait a minute... someone already started...
to be fair, I know exactly how whoever did this felt when this happened. And therefore I don't fault them for calling "this will have to be good enough for now". Haha. I did end up fixing it, but not before making it worse by breaking off the tip of a screw extractor in the hole. GRRRR! Finally just used a small carbide burr in a dremel to make a hole and then rethreaded with a tap. There's an hour or so lost but it's fixed at least.
Because I'm now diagnosing a no-start, I had my beautiful wife help me do a "unofficial" compression check.
so now where I'm at is I'd like to get the engine running well enough to either say it's good and I'm ready to fix smaller issues, or, it's truly skunked and needs to be replaced as a whole. to do that, I think my next step is checking fuel pressure. I'm thinking the engine ran ok with the mmo functioning as extra fuel in the chambers, and therefore as it burned off the injectors weren't able to keep up. So fuel pressure is next.
current "small" issues I'm aware of but not fixing immediately until I can prove the engine is fundamentally good:
I'd grab and squeeze all the oil pump lines, the ones on my FC all imploded the moment I touched them... and this car is now older than that car was at the time.
¯\_(ツ)_/¯ said:I'd grab and squeeze all the oil pump lines, the ones on my FC all imploded the moment I touched them... and this car is now older than that car was at the time.
Good idea. Like the oil cooler lines or the oil metering pump lines? I guess both isn't a bad idea, but I think the omp lines are hard lines.
In reply to Robbie (Forum Supporter) :
The oil metering pump lines- on the FC they were some sort of plastic, maybe they improved that by 1993.
After meeting you at the challenge, I can say I couldn't ask for a nicer guy to get so lucky and pick up such an awesome car. But also I'm jealous, So jealous, Berk You.
More Tools Than Sense said:After meeting you at the challenge, I can say I couldn't ask for a nicer guy to get so lucky and pick up such an awesome car. But also I'm jealous, So jealous, Berk You.
Ha! Well, thank you!
Great to see this being worked on!
You said the "smoke" didn't smell like coolant - did you refill it with coolant or with plain water? You found leaks so it was probably empty from sitting so long?
I really hope this turns out to be something relatively minor, but at this stage I haven't got a clue what that might be.
Following with great interest.
Have you done the fuel pressure check yet?
Do you have a spare CAS? (I'm not actually sure 3rd gens have them). If so, checking for spark and fuel injector firing is easy.
You just plug the spare CAS in to where the one is on the car. Then with the key in the on position, turn the gear on the bottom of the CAS. You can hear the fuel injectors clicking if the room is quiet enough.
You can also just take one of the spark plug leads off and put a spare spark plug in the end, ground it and watch the spark while turning the Cas gear.
Basically, a fairly simple way of checking spark and injectors without disassembling anything.
OMP lines are still plastic on the FD.
Good luck with the resurrection. Lots of good archived knowledge in the FAQ thread: https://www.rx7club.com/3rd-generation-specific-1993-2002-16/faq-3rd-gen-other-useful-links-68640/
IMHO, the FD is the sexiest car of all of the "Fast & the Furious 1" generation of tuner cars. Just such classic, classy lines.
Following along happily.
so_slow said:Great to see this being worked on!
You said the "smoke" didn't smell like coolant - did you refill it with coolant or with plain water? You found leaks so it was probably empty from sitting so long?
I really hope this turns out to be something relatively minor, but at this stage I haven't got a clue what that might be.
Following with great interest.
So it's a great question and I don't have a full answer yet. I was most worried about coolant leaking into the combustion chamber at first. And while yes, there are certainly external coolant leaks (water pump weep hole and the plastic fitting under the oil filter that goes to the heater core, maybe others too), I was hoping to rule out any internal leaks before trying to fix those.
i have not added any coolant or water yet. The coolant reservoir seems mostly empty. But the engine and radiator still I think are mostly full. I should think a little bit about how the system works and perhaps verify by removing the upper radiator hose at the radiator or something, but there is definitely still some coolant in the engine and radiator. And at least at this point it doesn't seem to be finding its way into the combustion chambers, but you are right a more thorough test will come after filling the cooling system to the correct volume.
wvumtnbkr said:Have you done the fuel pressure check yet?
Do you have a spare CAS? (I'm not actually sure 3rd gens have them). If so, checking for spark and fuel injector firing is easy.
You just plug the spare CAS in to where the one is on the car. Then with the key in the on position, turn the gear on the bottom of the CAS. You can hear the fuel injectors clicking if the room is quiet enough.
You can also just take one of the spark plug leads off and put a spare spark plug in the end, ground it and watch the spark while turning the Cas gear.
Basically, a fairly simple way of checking spark and injectors without disassembling anything.
I'm pretty sure there are 2 sensors, but they are triggered by a toothed wheel on the front pulley. So not easy to spin without spinning the motor.
Fuel pressure test today hopefully. I DID happen to notice that there was a big whooshing noise when I removed the fuel tank cap shortly after some cranking, after I removed the old fuel and refilled with 3 gallons of fresh fuel. I'm not sure if it was excess pressure or vacuum in the tank, but either would indicate a potential problem with the purge system.
In for FD madness, and also sorry I didn't hear about it first!
- The guy that was walking around with a rotor print on his T-Shirt.
And the fuel pressure is!
high?
dang. This means either the pressure regulator is messed up, or that there is a restriction somewhere in the return system. Good news is after I turned the pump off, the pressure sat constant for a good long while, which means I probably don't have leaking injectors at least.
since I did recently mess around with the return line at the tank (to drain the tank), I think I should probably start there...
Pressure seems correct to me. It's at least close.
I'm wondering if it is a bit flooded. Try starting it with the fuel pump off and see if I starts. This would also potentially indicate low compression.
I am deeply jealous! (Call me if you ever want to sell!)
When you started it, did you shut it off before it got up to temperature? If so, you may have flooded it, and the car will remain flooded for months. Rotaries do that.
The excess fuel injected at cold start needs to burn off. If it doesn't, it washes the cylinder walls, which reduces the seal assisted by oil on the cylinder walls. This reduces compression.
The answer is to pull start the car. You will need to pull it a long way, but it should fire.
Ive never owned an FD, but I have owned rotaries, and your description sounds exactly like a flooded rotary.
So with the fuel pump (circuit opening) relay removed, it did cough and sputter as the fuel pressure dwindled, which is more than it was doing before.
I hear you guys about flooding but I'm still not entirely convinced that I don't have an overpressure issue in the fuel system here. Fsm says 36-38 psi on a non running engine 32-34 while idling. 46 psi gets you a lot more fuel than 38. I could also try and watch the gauge while cranking to see if it goes down with vacuum.
Robbie (Forum Supporter) said:So with the fuel pump (circuit opening) relay removed, it did cough and sputter as the fuel pressure dwindled, which is more than it was doing before.
I hear you guys about flooding but I'm still not entirely convinced that I don't have an overpressure issue in the fuel system here. Fsm says 36-38 psi on a non running engine 32-34 while idling. 46 psi gets you a lot more fuel than 38. I could also try and watch the gauge while cranking to see if it goes down with vacuum.
That is WAY lower pressure than the 2nd gens ran. I was thinking they race like 45 to 50psi.
If it's flooded, killing the fuel pump and cranking it with the throttle wide open for 30sec or so should tell you- it may not actually start but you should begin getting more coughs and sputters as it clears out.
You'll need to log in to post.
