Lord Bro

Hey all. Just got my 93 Base in Florida and drove it back to Chicago a couple weekends ago.
Earlier in the week I had to jump start the car and move it, and later when I went to start the car (with a charged battery) so I could go grab stuff for an oil change it would crank and crank but not start.
I've got a gt35r w/pfc, so not stock.

After doing some reading to see what type of new owner mistake I had made that resulted in this, it looked like I had just flooded the engine. I attempted to deflood by just pulling the appropriate fuses and cranking the car with the throttle all the way down for a while, but to no avail.

I pulled the plugs and replaced them with new ones, checked for fuel pressure, and checked for spark, but still no luck. Today I pulled the new plugs and cleaned them up again, and cranked the car with fuses pulled to blow anything out of the plug holes. I made a few rags dirty and some gas blew out of the plug holes, reinforcing my belief that this is a flooding issue. Once I could crank and have nothing come out of the plug holes I lubricated with some idemitsu (no not atf) and let everything sit for a while after cranking once to help build compression when I tried to start again.
I put everything back together and waited for my battery to recharge, and tried to start again, but still it cranks and cranks but will not start.

Did I miss anything? I'd love to not have to take the car to a shop immediately, especially if I'm just missing something simple. Is a tow start the answer, or will that not work if what I have tried didn't work? It's been below freezing here, so I'm sure that doesn't help anything.

RotaryEvolution

iTrader: (30)

sounds like you covered all your bases, might be time to do the dirty and compression test the engine, even if it does merely sound coincidental.

Lord Bro

50 psi across the board unfortunately. At least the 2 times I drove the car were fun.

I'd be taking too big of a hit trying to sell the car immediately with a dead engine, so I'll go the rebuild route and see how I feel about life this spring.

RotaryEvolution

iTrader: (30)

sorry to hear.

heynoman

iTrader: (5)

Could have been worst could have been summer .......Tis the season. Winter is horrible out here and not like you were gonna be able to do much driving anyhow at least not without getting stuck all over the place... It does suck though Good luck with your build

Lord Bro

Thanks guys.
Once I have a better idea of what specifically caused this I'll come back and update. I wouldn't want other new guys to come looking and assume that they are in need of a rebuild just because I had some bad luck. For now I'll just say I suspect a fuel delivery issue that could have occurred under almost any conditions, but would be catastrophic under boost.

ZE Power MX6

iTrader: (157)

What tester are you using? How did the car run the last time you drove it? I'm just surprised you were able to drove it back from FL, and have a blown engine after moving it a couple times.

Lord Bro

tl;dr It drove just fine last time it ran. Trust me I am as surprised and upset as anyone since I was so careful to not mistreat anything. How could I have started in the cold one day, and have no compression the next?


As far as I could tell the car ran great last time I drove it; full story:
the power mods for some background:
PowerFC tuned by Steve Kan in December of 2012. Made 350-400 whp at 15psi.
~17K on motor, ~130K on chassis.
Emissions are blocked off, as is omp. Runs premix.

GT35R turbo
TurboXS SMIC
Pettit Racing duct
Greddy type-s BOV
Greddy Profec-b boost controller
Tial 44mm external wastegate
RX7store.net 3" downpipe and turbo manifold
Racing Beat Dual Tip catback exhaust and presilencer
Aeromotive FPR w/ fuel rails configured in parallel
Summit 30 micron fuel filter
Bosch 850cc primary, 1680cc fuel injectors w/resistors
Supra TT Fuel pump
ACV, AST, and EGR blocked off
Throttle body simplified
GM 3 Bar map sensor
Simplified single turbo wiring harness w/ emissions delete
PC680 battery with custom aluminum tray
Magnecor (mazdatrix) 8mm ignition wires
HKS TwinPower ignition amplifier
4 x NGK BURQ9 spark plugs
Koyo N flow radiator
JDM 5-speed transmission

I picked up the car in Florida and drove it back to Chicago over a couple of days, stopping in Nashville for the night to stay with family and rest. Since I had no plates on the car and was travelling with only the title (taped in the rear window in a plastic bag) and bill of sale I took it easy on the drive back so as not to attract attention. The only police encounter I had was the first time I stopped for gas, and he just wanted to compliment me on how clean the car was. I would say I drove 12 hours the first day, and 7-8 the 2nd. There were some nasty accidents on my way back into Chicago, so it took a bit longer than it could have.

It was 80-90 F in FL, and was down into the 40s in TN by the time I arrived there on the first day. Being new to the whole rx7 game I tried to be relatively careful on the way back. On cold starts I let the car warm up for a minute or two while I watched coolant temps, and then babied it and stayed completely out of boost until I hit 75-80 C on the Commander readout. Even then I didn't really have a ton of opportunities to drive quickly, as I was staying under the radar. When I stopped for gas I would pop the hood for a bit of ventilation and let the engine run for a minute before shutting everything off. Over the entire trip back I went WOT only a few times, and the car had been warm for quite a while each time.

The night after I got back to Chicago (so on Monday after work), I drove out to DeKalb to show off my new toy. This was Nov 9th, so those in Chicago know that it was in the 30s (F), and it dropped down into the 20s that night. Before I left I went and got gas and then left the car running while I checked my tire pressures, so it was nice and warm by the time I left. On my drive out I had no opportunity to get into boost due to crappy Chicago city traffic. Later in the evening when I arrived I did have the opportunity to give a friend a ride in the already warmed up car, but I was disappointingly not able to have too much fun as the road was too cold at night for me to have enough grip at the rear to really give it the beans.

Tuesday morning when I left the car didn't start, but it was very obvious the battery was the culprit as it cranked slow and I could see I was only at 10V or so on the Commander readout. We jumped the car with my friend's truck CORRECTLY, and it started up just fine once we had let the battery charge up a bit and disconnected everything. I also had no trouble on my drive back into the city, but similar to before never really got the chance to have any fun during that drive. When I got back I parked, let everything cool down a bit, and then went inside. A couple of days later I did have to move the car into my reserved parking area, and due to the tiny battery+cold weather I needed a jump again to do so.

It was the NEXT time I went to start the car my problems began. I was planning on doing an oil change since I had been on a long trip, but when I went out to start the car (which was now on a battery tender) it cranked and cranked but didn't start. It didn't stumble, pop, backfire, explode, burn to the ground, or make any sounds at all which I would associate with gasoline being ignited by a spark. Nothing.
I did a bunch of reading here on the forums and it really sounded like I had just flooded the engine after having started the car, moved it a short distance, and then shut down again. I tried everything I could think of and had read about (post #1), but had no luck. Not wanting to just let the car sit in some unknown state while I was away for the Thanksgiving weekend I took it to a rotary shop on the 24th and told them my sob story. I was pretty hopeful that I would come back into town on the 29th and have a running car, but got a couple pieces of bad news that evening:
(1) The fuel pump wasn't working correctly. When you turned the key far enough for the fuel pump to build pressure you could see the pressure build up on the FPR and then drop a bit. When cranking you could see the pressure fall drastically. Swapping in a different pump for testing eliminated this behavior, sooooo dead fuel pump.
(2) No compression. I was sent a couple of videos where I could see that compression was at about 50psi all around as seen on the compression tester gauge. I have no idea what tester it is, but it's the one the shop uses on it's other cars so I'm inclined to believe the readout is correct.

I can't believe my bad luck, and I have no idea when this happened. I too have no idea why it seemed fine right up until I couldn't start, but a compression test doesn't lie, right?

ZE Power MX6

iTrader: (157)

I would do a bit more troubleshooting, maybe post up the compression video.

RotaryEvolution

iTrader: (30)

the numbers are likely lower due to the flooding, but if the compression test was done properly even a flooded engine should not have 50psi and will result in a no start condition.

it is possible the engine was moderate on compression to start with and running the engine without allowing it to warm up is a recipe to flood it.

now what would cause such a thing? generally it is in the tuning, if the engine was built with any "indestructable seal" variant they tend to really not like a stock-sh AFR or moderate tune, the tune on such an engine should be made conservative with slightly richer moreso than slightly leaner mixtures. gouging and seal warpage is a result.


a compression test prior to purchasing a rotary car is always a good idea, if it came back in the sub 85psi range then it is very possible that it continued to drop on your cross country drive to critically low levels, even though it would start ok prior. only a very slight lack of power from a dead stop would be any hint of a problem, once a rotary engine is running, compression plays a small role in its duty.

you could try having the shop get the engine running(if this is a rotary shop they should have no problem getting it to start) and do a decarb on it, but that is about a $300 gamble that the numbers will come up a bit.


next issue, ditch the mini battery even if you have to relocate the battery. slow cranking is really tough on a rotary car.

the last thing i would do is contact the seller and explain the situation to them and hopefully at least get some of the repair costs covered.

Lord Bro

(1) (2) The videos are in the worst possible quality given they were texted to me, but you can see the needle is under the 60psi mark every time.

The only time I ran the engine and didn't allow it to warm up was when I reparked the car the last time before it wouldn't start.

I would say a compression test before the purchase of any performance car is a good idea. I did ask about the compression when I bought the car, and the previous owner said it was up around 100 on each rotor.

I'm not against ditching the small battery, especially what with the colder weather up here. After I needed a jump the first time I ordered a battery tender and a lithium battery in case I needed a jump again, so there has only been a small amount of slow cranking, and excellent cranking amps the entire time I tried getting it started again.

Basically what I'm hearing here is that if the (yes rotary) shop could get it started and blast the carbon off everything I may get some compression back, but probably only enough to know exactly how deep a pile I'm in. I've got good cranking amps, spark, fuel pressure, and fuel delivery.

I've been avoiding contacting the previous owner as this car was his baby, but sounds like it may be time.

Edit: Surprise! Called the shop to ask about the dead fuel pump. Turns out it was the stock unit. I have no doubt the previous owner bought it like this, so he didn't know.

RotaryEvolution

iTrader: (30)

what?

a stock pump is only good for about 300whp, the 35R that is on the car is good for 400-450whp at 15psi and a mere 350-400whp at 10psi.

something is not adding up there or they are mistaken about what pump it is. the supra TT pump looks like the OEM pump but can keep up with the 35R on low-moderate boost, but the supra TT pump does not like the stock FD wiring/amperage supply. i have a feeling they just didn't look at the pump hard enough(dimensional and physical appearance is exactly the same as the FD fuel pump)... the stocker would pop the engine with the 35R barely starting to spool up.

a deflood and decarb may at least buy you a little more time to enjoy the car before it going back in under the knife.

it being someone's baby is of no consequence when you are the one shelling out several thousand dollars only weeks after buying the car, you should be more concerned about your feelings than the person's who you paid for a running car that no longer runs. if i sold someone a car that needed an engine just after getting it home, i should feel bad about it.

gweedo

I would try bump starting it get it running. Then do a compression test before rebuild. At this point you don't have much to lose I'm thinking the rotors are washed down from fuel.

Lord Bro

Thanks to everyone for all the help and suggestions. I did decide to go the rebuild route, and wanted to update with what has been discovered: apex seals look ok or at least not broken on initial visual inspection, but the side seals are shot.

If anyone else new finds this thread, I'd like to stress that I tend to be unlucky in these things. From my reading at least, a new owner with symptoms of a flooded engine... usually just has a flooded engine
The old owner is a stand up guy, and when I contacted him to let him know what had happened he offered to help me out with the repair costs.
Not everyone is as fortunate in this type of situation though, so my biggest suggestion to anyone else looking to buy their first rotary car is to find someone who knows what they are about to come take a look at the car with you. I mean, RotaryEvolution is in Florida; I could have offered to pay for gas + beer for him to be an extra set of eyes for me.

I'll be starting a build thread to catalog everything I'm doing to get the car back on the road and tuned, plus my other plans. This isn't how I wanted to go about learning everything about these cars, but man it's going to be a good crash course. I'll learn a lot.

Balefire

Even veterans make mistakes. With my old rx8, our local rx8 club had cards that I would give the dealer and pasted in my rx8 for maintenance detailing how important it was not to turn off the car early.

anyway, 2 years into ownership of my old rx8 I flooded it moving my car in my driveway in the winter while moving during a party. that costed me a lot of pain and time to fix. also costed me my catalytic converters which mazda graciously fixed for free.

hope your car runs again soon!