pp13bnos

iTrader: (1)

I want to start out by saying that I want to thank everyone who's helped me with my car so far. The most important people have been Ralph Friend (Xcessive.), Rob Golden and a local friend/RPNW member, Dom. Anyways, this last year I began installing a single turbo on my 3rd gen. Progress was slow, but eventually the car came together. The turbo kit consisted of a SR stage II turbo, XS cast manifold, HKS 50mm wastegate with ~10psi spring, Greedy Type R Bov, and a 3" DP. Other supporting mods are a 3" mid pipe, and apexi N1 dual tip, 850cc primarys, 1300cc secondarys, Groundzero fuel pump, relocated Aeromotive -10 inlet/oulet, 10 micron fuel filter, Power FC, Profec B boost controler, Spyfish intercooler (M2 medium style.) big freakin' air filter, removed double throttle, relocated air tempature sensor, Crane HI-6 amp, 9s in leading and trailing, Jacobs ignition wiring.

Once everything was installed, I had Ralph Friend tune the car on his mustang dyno. It put down around 340rwhp@14ish psi, and nearly 400rwhp@16psi. After the dyno session, i drove the car aound, and it drove fine. There was no igntion break up, missing, etc. After paying Ralph, I got back in the car and drove upto North Portland to pickup a Yamaguchi Book on the Rx-8 from a local seller. On the way their, I noticed that the car suddenly was falling on its face under boost. The car would litterly die under boost above 4,500rpms or so. I quickly called Ralph, and told him what was happening. (I did check the map sensor first) We set up anouther dyno appointment the week after. In the mean time, I put a new set of plugs in the car, and pretty much made shure everything was hooked up correctly in the engine bay. At no time did I even touch the commander, or the tuning. The next week we put the car back on the dyno, and measured fuel pressure and its relation to the boost level, via the mustang dyno. Ralph overlapped the fuel psi, and boost psi on his computer, and the two where right ontop of one anouther. The fuel pump, and regulator where doing their job perfectly. According to the wideband at around 4-4,500rpms it would start to go supper rich. By 4,500rpms (According to the dyno) I was reading richer than 10-1 a/f ratio. Very odd, because Ralph tuned the car for a 11.0-11.3-1 a/f ratio with very conservitive timing. Ralph decided perhaps it was in the software of my computer and initialized my P-FC. He uploaded a different map off of anouther car he had recently tuned, but with the same results. At this point we begain to think perhaps it was either spark, or fuel injector problems. Having nothing else we could try, I whent home. Something we did figure out is, that it is RPM and load based....wich makes me think that it was igntion.....

At home I decided to pull the plug wires, ohm them and inspect them. They where nearly new, but I decided I'd check anyways. They checked out a-ok. After that I borrowed a set of coils, and set o CASs from a friend of mine. (Dom of RPNW) I installed them one at a time but there was no change in the cars behavior. I tried unhooking the HI-6 to see if it was the problem...but with no sucsess. I installed my ignitor in Doms car to see if it was still working. His car ran great with my ignitor. At this point I whent through my car and cleaned all the grounds in the engine bay and power FC. Still no change in my cars attitude. Next, I removed the coil wiring harness, and engine wiring harness to remove all the unneeded emmisions related connectors and wiring. While it was out, I checked to see if there was any breaks, broken wires, burnt wires etc. All came back good. I retaped the harness, and installed it back into the car. Still no change in driving the car. I'd like to also state that according to the power FC, that the air temp, tps, water temp, etc. and all the other needed solenoids where all working correctly, with no funny readings the entire time I've been testing my car. After the install and test of the wiring harness, I swapped out my 1300cc secondarys for the stock 850cc...thinking perhaps they where the main problem. No luck. car still ran like a p.o.s. (I did change the power FC setting to a 850cc map Ralph gave me.) Next, I put in a new map sensor with no luck. Next on the list was to remove the fuel pump voltage regulator thingy located under the break booster. (Its now located in a box under my work bench.) Along the way the powersteering was removed as with the AC. So far I don't miss either one, other than when traveling less than 3mph. I've check many times for vacuum leaks but am yet to find one. I've also tried running other fuel than the 100octane I dyno'd with. No change. From time to time, when doing all this work, I'd pull the plugs and take a look at them. While not being fouled out, the car was'nt running lean either.

At this point, Ralph and Myself are running out of ideas, and the car is starting to become a major pain. I just dont understand what could be causing such a overly rich conditon that started very suddenly. I realy like the car, but am starting to get tired of allways trying to figure out whats wrong with it. I'm starting to think of putting it up on jack stands for a couple months or maybe a year, then, take a step back and forget about it for awhile. Then come back to it, with a new focus and a new direction maybe. I don't know guys.....I don't mind spending the money on getting this car running right....but I don't want to throw $$ swapping out parts blindly.

Does anyone have an idea of what could be the problem, or a suggestion? Any help would be very helpfull. Thanks

RX7Wishing

wow, you get an A+ for troubleshooting and documentation, just be reading this very detailed post i was compelled (sp?) to drive to your house and give you a hug. lol.

Anyhow. is there anyway you could swap your PFC with someone elses to see if it cures the problem. do you still have the stock ECU? if so, with the 850s in try putting in your stock ECU and see if that cures the problem.. Damn, if you lived near me i would come over and we could try my ecu. good luck.

JaNusSolSumnus

Would the stock ECU even function properly with the single turbo and loss of all emissions equipement? I didnt think it would, I'd say it would make the condition worse trying to compensate for the differant A/F demands. Not to mention the upgraded ignition and fuel system.

~Kris

SPOautos

What did your power do from the good runs to the bad runs given the same boost level.

I've watched a lot of dyno runs before and your problem sounds exactly like a small boost leak, usually from the bov leaking. I've seen it happen quite a few times where it seems like you have to pull tons of fuel to get it where it needs to be and the bov was just leaking. They would keep the same pressure level it would just be less cfm....hence the super rich condition

Have you tried putting your hand in front of the bov while on the dyno? If not you should do that.

I've also seen the same thing happen from slight IC pipe coupling cracks, they are hard to find cause you usually cant see them till under boost when the crack expands. Typically you just have to pull the all off the car and inspect them. I've also seen it happen from a loose clamp that allows the coupling to expand and leak when under boost.

I know your prob thinking....there's no way it could be a boost leak but trust me I've seen it happen a lot and the symptoms are exactly like your describing.

STEPHEN

RX794

I had this same problem like 4 years ago with a Pettit ECU, and it turned out to be that I had a boost leak from an intercooler end tank open up on me under pressure when boost was coming in, which coincedentally was at 4500rpms, I know it's WAY of a long shot, but check that.

allrotor93

iTrader: (126)

i had a similar problem and it was the ignitor.

KibagamiR2

Check your clutch pedal switch if it is broken. If so, it can cause an overly rich condition. Just something to check...

-Kib

RecKleSs

Another problem could be the turbo itself, which you said, "I noticed that the car suddenly was falling on its face under boost. The car would litterly die under boost above 4,500rpms or so." KKK stage II is known for having some problems even when they are new. Also, another FD with the KKK II made 405rwhp @ 14 psi, however, it had a ported motor. Anyway, good luck and don't give up.

RX7Wishing

there are plenty of people without the air pump/egr blocked on stock ECU's. and obviously you didnt read my post clear, because i stated if he still had his 850's in the he could test witht he stock ecu.. And the stock ecu would function fine witha single turbo kit. Not safe. but it would work and let him know if his PFC was the issue.

LT1-7

CJ, was that you a while back that posted about your injectors being stuck open? If so, I would take those inj. out and have them checked out. 4500rpms is where your problem is and that's about when the secondaries kick in.

Also, what does your commander say is your peak boost? Check to see if it's totally off. If it is, the pfc might be in 3bar map sensor mode. Don't ask how but James' pfc suddenly got switched to 3bar map out of the blue. Took us a few hours to figure out why it was running so rich.

Get your car up so we can meet at woodburn!!

JaNusSolSumnus

I noticed you covered the injectors but he still has the high-output fuel pump, I dont know if that would effect anything given the stock ECU, thats the only reason why I mentioned it.. because I didnt know for sure.

~Kris

jspecracer7

He's NOT RUNNING A STOCK ECU.

jspecracer7

Could you elaborate a little bit on this please. That's the first time I've ever heard this one...

JaNusSolSumnus

Well, someone is being stingy with their hoo-hoo...

I know that, he's running a PFC, as suggested by another member though, he was talking about sticking the stock ECU back in and seeing what it would do.

~Kris

RX7Wishing

a stock ecu should still work with his mods.. is my point.. jeeeebus!!!

JaNusSolSumnus

I wasnt trying to offend, consider it a lack of information on my side... hence why I asked about what would/wouldn't work with the stock ECU. I didnt know if the fuel pump and turbo would effect the ECU's ability to function, now I do, my apologies.

~Kris

KibagamiR2

Well the clutch switch can cause, at least on my FD it did, a lower idle and a rich condition if that switch is broken. I realize he is talking about problems while moving and under boost and the switch really *shouldn't* affect the car while moving. However after he seems to have tried so many things, I thought it would not hurt to check that switch since it should be easy to verify if it is ok or not. It would be something else he can rule out of his now long list of things he has checked. Anyway here is a long search list of threads related to the clutch switch and the symptoms:
https://www.rx7club.com/search.php?s...der=descending

-Kib

pp13bnos

iTrader: (1)

Thanks for the thought of driving over. After typing this all up I called Ralph again, and this is what he mentioned. Try swapping out my power FC with somone elses. This is going to be my next step.

Actually when on they dyno Ralph did adjust my BOV by the hand over the mouth of it trick. I actaully even asked him what he was doing. Then he explained it to me.

But as far as a vacuum/boost leak I'll double check and triple check it this weekend for shure. I'll pull off all the block off plates and get some new gaskets and stuff.

As far as power levels, I don't even think we compared the two runs. They where only partial runs to make shure we where'nt loosing fuel pressure or anything like that. I should have checked but did'nt even think about it.

John, I did have a 1300cc stick wide open. This was caused by the stuff that RC uses to clean them out. What happens is, if the injector sits for a long period after being cleaned, the solution will cause the injector to stick. At this moment, I'm running 850cc in the primarys, and 850cc in the secondarys....just to take the 1300cc out of the equation.

My commander is around 2psi lower than my boost gauge. But this has allways been the case. Ralph says he commonly sees this with the autometer boost gauge I'm running. Also, this is one of the first things Ralph asked me about when we did our tuning session the second time. So, the P-FC is setup for a stock map sensor.

KibagamiR2, at this point, I'll try anything. I'll check it out after the P-FC swap.

Allrotor, I'll see if I can borow one from a friend and see if it helps. But this will probably happen after the p-fc swap.

Thanks everyone for the advice so far. CJ

rotarypower101

iTrader: (1)

Hey CJ if you cant find a PFC to swap in, I can borrow you mine just PM me if that is the wrought you are going to go. though I hardly think it is the problem but it would be nice to take one more variable out of the EQ

pp13bnos

iTrader: (1)

That would be great! Or we could hook up sometime and we could swap my ecu into your car and see how it reacts. Are you running a single on your car too? CJ

SBi_Owner

This is a shot in the dark but........
Have you thought of going with different plugs, maybe a lower heat rating? It sounds like it mey be detonating due to heat and high boost pressure. Like I said, it is a shot in the dark.

pp13bnos

iTrader: (1)

Just a little update. I don't understand this....but it seems the more I drive the car, the more it clears up. At this moment, it starts missing around 5,500~6,000rpms or so. I'm going to drive it when ever its dry enough to work all this week, and will keep everyone updated. Thanks, CJ

teeter

a good way to check for boost leaks is to go to the hardware store and pick up a 4 inch rubber coupler...and a 4 inch pvc plug...and a air compressor fitting.

drill/screw the air compressor fitting in the plug. clamp one end of the plug to the rubber coupler...and clamp the other to the turbo intake. Hook up air compressor and run it up to say 25 psi and listen for leaks. Fix leaks...repeat...etc...

i haven't heard of people making these on these forums..but for guys who have MAF sensors...these boost checkers are essential.

on a second note...if your injectors are sticking open...maybe some fuel injector cleaner would help?

john

pp13bnos

iTrader: (1)

I don't think the motor would hold pressure. It would leak around apex seals, corner seals, side seals, and escape through the exhaust ports and stuff. CJ

pp13bnos

iTrader: (1)

I'm hoping someone can point me in the right direction here....

When driving my car yesterday, i was checking out the sensor check mode on the commander. Every once in awhile the "water" one would light up. (Indictaing something is'nt quite right with the sensor.) Could a malfunctioning water tempature sensor cause problems such as this?

The reason why I ask is....I know the dash guage water temp. sensor is located by the oil psi sensor (On the back steel.) and I beleive the ecu one is located on the back of the filler neck (Green plug)....but here is the weird part. The tempature on the commander reads fine. Anywhere from 83C~92C. No hickups or anything like it. Does the ecu get its water temp reading from a different source? Like the little plug in located just beneath the Green plug?

I'm probably going to buy a wideband pretty soon. So I can keep an eye on the a/f ratio. A buddy just gave me a free (Old. ) laptop, and the final step will be a datalogit. That way, I can realy see whats going on.

Thanks guys for the input. CJ