flooding out FC3S4 N/A

Shadow24v · 02-13-2009, 07:47 AM

Im working with the guy selling me an 86 FC3S4 to get it running before i have him paid off. initially this is what he said:

Quote:

It ran pretty good, had good power, ran a little rich, idled good but would try to die out after revving it, it's a bit rich I think. I did a compression check, twice, came up w/ 80-90 psi on all rotor faces (FSM says 85 minimum, my TII runs on 50-60 psi). It doesn't run at the moment because the CAS (crank angle sensor) is bad and I haven't went and got one to replace it. We got it in at the junkyard not running, and we've got it running several times, then it won't run again. Probably partially due to the bad CAS, partially due to whatever is causing the smoke.

I secured a used CAS and he swapped them but

Quote:

I got the CAS today, stuck it in, it fired a bit but wouldn't quite catch. It seems to just be flooding out almost instantly, I dunno if an injector or two is stuck open or what. Stupid car lol

He's got a T-II FC for his own and is a competent mechanic. I just picked up some known good injectors to send to him, but does anyone have any additional thoughts on what might be causing it to flood that fast?

Ender · 02-13-2009, 09:58 AM

Low compression is a likely culprit. If gas blows past the seals much it'll wash out the oil needed to seal the chambers, and then it'll just crank and crank because it can't build compression. This is a very common problem with low compression rotaries. A temporary fix sometimes works, you can install a fuel cut switch so it doesn't just POUR fuel into the chambers on startup. You probably will have to rebuild a motor with that low of compression before soon though. I would keep that in mind. My TII came to me with probably 80psi compression and had the same trouble starting and I used a fuel cut switch to help it start. I was probably lucky to get ~8,000 miles out of it before it let go. I knew it was coming though and I had stocked up on all the parts I needed for a rebuild, so when it died I was prepared to build myself a new, better motor.

Shadow24v · 02-13-2009, 10:31 AM

i thought 80-90 psi compression was good....(HIS T-II has the 50-60psi, not the N/A he's selling me)

does the FC have a flood threshold for the throttle? floor it on crank and it cuts fuel?

any way to temporarily re-oil the seals? put a bit of oil in through the intake or spark plug holes and crank it over?

Max777 · 02-13-2009, 11:54 AM

Quote:

Originally Posted by Shadow24v

i thought 80-90 psi compression was good....(HIS T-II has the 50-60psi, not the N/A he's selling me)

does the FC have a flood threshold for the throttle? floor it on crank and it cuts fuel?

any way to temporarily re-oil the seals? put a bit of oil in through the intake or spark plug holes and crank it over?

you know, that might have just been the gauge.

I tested my car with two gauges that both got 90psi, and then with this other one that only displayed 50psi, and I was like WTF?

So it might just be the gauge.

My5ABaby · 02-13-2009, 06:46 PM

Quote:

Originally Posted by Shadow24v

i thought 80-90 psi compression was good....(HIS T-II has the 50-60psi, not the N/A he's selling me)

does the FC have a flood threshold for the throttle? floor it on crank and it cuts fuel?

any way to temporarily re-oil the seals? put a bit of oil in through the intake or spark plug holes and crank it over?

The S5 cuts fuel if you put the pedal all the way down, but the S4 does not.

http://www.rotaryresurrection.com/2n...nflooding.html

Whizbang · 02-13-2009, 11:13 AM

injector problems CAN be the cause of the issue. I had a string of rx-7s come through once that all had serious running issues from constant flooding, stalling and bucking. They all turned out to have bad injectors.

vex · 02-13-2009, 12:55 PM

90 is rebuild time. My NA rotors pump out 110-115 on both faces with pulses up to 60PSI on any single compression.

Shadow24v · 02-13-2009, 01:02 PM

well, i can't afford a rebuild ATM, (student, i.e. broke as hell) provided the engine is in good shape, can a rebuild be just the apex, side seals and a small list of other parts? the master rebuild kit on Atkins was like $900...

Im hoping that its the injectors and she'll run with better ones. im guessing an oil change is in order after all the flooding.

Max777 · 02-13-2009, 01:09 PM

I know I will need to rebuild the engine, but a 100k one is better than a 140k one, so for now it will do. (old one had a coolant seal pop in 3 places on the front iron)

Flooder · 02-13-2009, 01:58 PM

50-60 psi is really low, even for a TII. And you can't compare compression numbers between an NA and a TII. TII's come with lower compression rotors and NA's are higher compression. So if you had an NA and a TII that both got 80psi, the NA is probably a lot weaker than the TII.

So back on topic, the motor probably has lower compression than he's telling you. If the injectors you sent him weren't professionally serviced then they will still probably leak and cause more flooding. The injectors and low compression are what cause flooding.

Shadow24v · 02-13-2009, 02:14 PM

any particular reason you think the compression numbers are lower than he says? (hes a long-time member of a forum im on and a standup guy by general consensus) FWIW the injectors i sent came out of a running N/A so...*shrug*

on the subject of rebuilds, is there a quick and dirty rebuild to get the compression up to where it should be? im not liking the $900 pricetag for a master kit... aside from seals etc, can you do just the seals and such and have a refreshed motor?

vex · 02-13-2009, 02:37 PM

Quote:

Originally Posted by Shadow24v

any particular reason you think the compression numbers are lower than he says? (hes a long-time member of a forum im on and a standup guy by general consensus) FWIW the injectors i sent came out of a running N/A so...*shrug*

on the subject of rebuilds, is there a quick and dirty rebuild to get the compression up to where it should be? im not liking the $900 pricetag for a master kit... aside from seals etc, can you do just the seals and such and have a refreshed motor?

The only way to save money on a rebuild would be to see which seals are still in spec (IE Apex seals). If your Apex seals are still in spec you can probably find a kit that doesn't have them included which can save you some money. Also, find out if your oil rings are in good condition as well as your side seals, then you might not have to get those seals either (though it is a good idea). After that you will just need a gasket and seal kit for taking it apart. Honestly if you're getting low compression and you're flooding out it very well could be leaky injectors in which case your compression numbers are lower than what they should be. If the injectors are not faulty and are in good condition you're still low on the compression side which can mean a few things. Your apex seals are out of spec, your side seals are toast, etc. It just all depends.

DJMOJO · 04-10-2009, 09:37 AM

no not really. if you tear down the motor to rebuild just a few seals you will be wasting a ton of time for nothing, if you tare that thing apart make sure you do it proper and have a master kit waiting for it. you'll be doing yourself a huge disservice otherwise

vex · 04-10-2009, 10:56 AM

Quote:

Originally Posted by DJMOJO

no not really. if you tear down the motor to rebuild just a few seals you will be wasting a ton of time for nothing, if you tare that thing apart make sure you do it proper and have a master kit waiting for it. you'll be doing yourself a huge disservice otherwise

Why on earth would you need a master kit? Especially before what you know is in spec and what isn't?

Why replace the rotor bearings if they're still in spec?
Why replace the stationary gear bearings if they're still in spec?
Why replace the Apex seals if they're still in spec (assuming the engine has 2 piece seals)?
Why replace the side seals if they're still in spec?
Why replace the corner seals if they're still in spec?
Why replace the oil control rings if they're still in spec (I'm referring to the hard rings and not the soft seals which are replaced during a rebuild)?
etc
etc
etc

You shouldn't ever buy a rebuild kit before you know what's in spec and what isn't. You can save so much more money than just buying a master rebuild kit. Sure you can buy a master rebuild kit and be done with it and know that you're going to have an engine that should theoretically last over 100k, or you can replace what's been worn out of spec and get an engine that should theoretically last over 100k.

Shadow24v · 02-13-2009, 02:42 PM

ok, ill see what happens with the new injectors. ive had experience with gunked injectors on my Duster, so i know how much of a PITA a stuck open injector is.

Atkins had a rotor kit or something like that which was apex, side seals and some other parts. is there another supplier for rebuild parts other than atkins?

02-13-2009, 11:13 AM	#6
Whizbang Respecognize! Join Date: Jul 2008 Location: Δx = ħ/2Δp iTrader: (5) Posts: 3,190 Rep Power: 20	injector problems CAN be the cause of the issue. I had a string of rx-7s come through once that all had serious running issues from constant flooding, stalling and bucking. They all turned out to have bad injectors. __________________ For current updates and event coverage check out Follow on Twitter! @WhizbangRally Whizbang Rally's Webpage \| Facebook

02-13-2009, 12:55 PM	#7
vex RCC Loves Me Not You Join Date: Jul 2008 Location: Influx. iTrader: (6) Posts: 2,113 Rep Power: 19	90 is rebuild time. My NA rotors pump out 110-115 on both faces with pulses up to 60PSI on any single compression. __________________ The Official FC Radiator Thread My Project Thread: Cerberus CCVT Virginia Rotary Group

02-13-2009, 01:09 PM	#9
Max777 Pirate Join Date: Mar 2008 Location: Central IL iTrader: (5) Posts: 1,323 Rep Power: 18	I know I will need to rebuild the engine, but a 100k one is better than a 140k one, so for now it will do. (old one had a coolant seal pop in 3 places on the front iron) __________________ Rotaries:They are NOT that complicated!

02-13-2009, 01:58 PM	#10
Flooder Rotary Fanatic Join Date: Feb 2008 Location: Tucson, Arizona iTrader: (0) Posts: 321 Rep Power: 17	50-60 psi is really low, even for a TII. And you can't compare compression numbers between an NA and a TII. TII's come with lower compression rotors and NA's are higher compression. So if you had an NA and a TII that both got 80psi, the NA is probably a lot weaker than the TII. So back on topic, the motor probably has lower compression than he's telling you. If the injectors you sent him weren't professionally serviced then they will still probably leak and cause more flooding. The injectors and low compression are what cause flooding. __________________ AZRX7.COM Red 1991 A-package(SOLD) Red 1990 GXL(SOLD) White 1989 GTUs(DEAD) Red 1988 Turbo II(DD) Black 1988 Turbo II(SOLD) Rebuilt and street ported motor, Garrett T04E Turbo, 3" Turbo Inlet Duct/AEM Dry Flow Filter, Your Mom's MBC, Blitz FMIC, 890cc and 1000cc injectors, Tomei FPR, Walbro, Rtek 2.1 ECU, Taurus E-Fan, Turbonetics BOV, 3" Motoria/Corksport Turbo Back Exhaust, Emissions Removed, Greddy Boost Gauge, Megan Racing Water Temp Gauge, 5one5 Triple Gauge Pod, AEM Uego, GP Sports Body Kit, Fiber Images CF Hood, S5 Seats, S5 Tails, S5 Alt, Dual Alt Pulley, D2 Coilovers, NRG Quick Release, Shook Motorsports Radiator, HID's, AN/Steel Braided Oil Cooler Lines, SUPER JDM TYTE DRIFT BUTTON www.DensetsuMotorsports.com www.AZRX7.Com www.FloodersAdventure.com

04-10-2009, 09:37 AM	#13
DJMOJO The only DJ in RCC Join Date: Apr 2009 Location: Tucson AZ iTrader: (0) Posts: 20 Rep Power: 0	no not really. if you tear down the motor to rebuild just a few seals you will be wasting a ton of time for nothing, if you tare that thing apart make sure you do it proper and have a master kit waiting for it. you'll be doing yourself a huge disservice otherwise __________________

02-13-2009, 10:31 AM	#3
Shadow24v Rotary Fan in Training Join Date: Feb 2009 iTrader: (0) Posts: 69 Rep Power: 16	i thought 80-90 psi compression was good....(HIS T-II has the 50-60psi, not the N/A he's selling me) does the FC have a flood threshold for the throttle? floor it on crank and it cuts fuel? any way to temporarily re-oil the seals? put a bit of oil in through the intake or spark plug holes and crank it over?

02-13-2009, 01:02 PM	#8
Shadow24v Rotary Fan in Training Join Date: Feb 2009 iTrader: (0) Posts: 69 Rep Power: 16	well, i can't afford a rebuild ATM, (student, i.e. broke as hell) provided the engine is in good shape, can a rebuild be just the apex, side seals and a small list of other parts? the master rebuild kit on Atkins was like $900... Im hoping that its the injectors and she'll run with better ones. im guessing an oil change is in order after all the flooding.

02-13-2009, 02:14 PM	#11
Shadow24v Rotary Fan in Training Join Date: Feb 2009 iTrader: (0) Posts: 69 Rep Power: 16	any particular reason you think the compression numbers are lower than he says? (hes a long-time member of a forum im on and a standup guy by general consensus) FWIW the injectors i sent came out of a running N/A so...shrug on the subject of rebuilds, is there a quick and dirty rebuild to get the compression up to where it should be? im not liking the $900 pricetag for a master kit... aside from seals etc, can you do just the seals and such and have a refreshed motor?

02-13-2009, 02:42 PM	#15
Shadow24v Rotary Fan in Training Join Date: Feb 2009 iTrader: (0) Posts: 69 Rep Power: 16	ok, ill see what happens with the new injectors. ive had experience with gunked injectors on my Duster, so i know how much of a PITA a stuck open injector is. Atkins had a rotor kit or something like that which was apex, side seals and some other parts. is there another supplier for rebuild parts other than atkins?