Probably what I'll do.

 

Man, that sure sounds like what my car did when I was in limp mode. If I reved the engine up with very little throttle, it sounded ok. But as soon as you put any load on the engine, or gave it more than a little throttle, it would pop and stumble. According to the factory service manual, when in limp mode, the computer sets a constant amount of fuel injected on the secondaries. So it basically cuts off your fuel.

The main reason I was leaning towards a clogged cat was because you said you couldn't hear the turbos spool and the turbo region was abnormally hot. And your lack of trouble codes. When I was in limp mode, I could hear my turbos spin up a little, and I got maybe 1 or 2 lbs of boost, but there was not enough fuel so I couldn't get past that.

 

And the main reason(s) I'm leaning toward damaged twins in transist is:

Cat wasn't clogged before
Zero Trouble Codes
Can't build boost
Adnormally hot in turbo region (and heats up QUICK)
Feels like limp mode when boost gets to 0psi (bogged with fuel)
Injectors clean/bal/calibrated
Can't hear twins spool
Twins were fine before

There might be more but that's all I can think of.

 

I'd love to hear from any of the other 200 views this thread attracted also...I just can't think of what else to troubeshoot, and I'm starting to think the worst...twins are damaged and I'm screwed, because I can't prove they were fine before...besides a amature video I shot the day before I started the project...but didn't get on it hard enough for the second turbo to come on-line. I also have a bunch of pictures of the box UPS dropped out of a plane onto my door step with the front turbo in complete view (from the outside) and of the, "FRAGILE: Contents of this box left our facility (Pettit) in perfect condition...blah blah blah" sign on the box.

If someone could give me insight on how to approach that situtation, that'd be great too.

TIA

 

Spoke with Cam yesterday and convinced me I didn't need a HF Cat, and my cat was fine unless something crawled in there and died...So my exhaust is back on, and he gave me a check to assure me that the twins were spooling (pulled what use to be the CRV and rev; I could feel air coming out) So I think I was just freaking out like a woman yesterday when I was thinking the worst.

So, I noticed that when the WOT code was thrown (60% throttle) on the PMC commander, is when I was having the hesistation/fuel cut. Thought maybe the PFS PMC was in limp since I have no error codes...pulled the computer to run tests...same thing. I have a video of tach reving in neutral (if anyone would like to host it) and I CAN rev passed 4k until light throttle, but anything 60% or greater it revs to 4k drops, revs to 4k and drops...like a rev limiter -> Limp Mode, eh?

So Now my question is what is putting my car in Limp Mode with NO CODES...after the check flight I tried pulling codes again -> Nothing. Secondaries??? I placed a screwdriver on the top of the front injector and the other end to my ear, I can hear noise, but as far as telling if it was firing...your guess is as good as mine (and you didn't have a screwdriver to your ear and you weren't at my house).

Wouldn't a code get thrown if they were malfunctioning? Or is the code thrown only if they're not plugged in?

We are so close, some techniques to trouble shooting would be great. And if some limp mode experts could chime in!!!

Conclusion:
cat not clogged
turbo spooling (can't get enough exhaust flow to build boost)
not a problem with PFS PMC
not getting bogged down with fuel
No codes & what to appears to be limp mode

TIA

 

I had a stuck secondary injector once. The car would stumble and fall on its face if I tried to go over 4000 RPM or went into any boost. A bad electrical connection to a secondary injector would have the same effect. That sounds very much like what your car is doing, so I would look at the secondary injectors. Apply power to them and see if they make the same click when you do. If one sounds dead, that's your problem.

-Max

 

Thanks Max, good tip. Would a bad connection throw a code?

 

Glad to see you're making some progress

Check in your FSM and see if there are any trouble codes for the injectors themselves. Each injector has two terminals, I assume a power and a ground, so I would tend to think that the computer wouldn't know if there was a bad connection. You just got them cleaned/balanced, right?

 

Thanks, and yes they were (by RC Engineering; to add if anyone is thinking of this service, mention this forum and get 10% off)

 

Same as checking other codes, I assume jump FSM and GND, watch for CEL...

I haven't seen that in the manual yet. Do you where I can read about limp mode, also. Did a lot of reading last night and couldn't find limp mode. It was late and maybe I'm an idiot

 

I'll look tonight about limp mode. The FSM doesn't say much about it... it doesn't call it limp mode either. All I remember reading was that if there was an OMP malfunction the computer would limit the secondary injector volume or something like that. I'll look it up tonight and get back to you.

 

Yeah I'm an idoit, I thought you were saying FSM was something like TEN...and I had to jump it to GND and check for codes...BAHAHAHA!

I got'cha...

I guess I need to do what Max said...here we go again off with the UIM.

Edit* I don't think one could be dead...maybe bad connection?

 

Ok I totally neglected my baby over the weekend, but I did happen to disconnect the front secondary fuel injector and pull a 71 code..."malfunction of front secondary" So I'm sure the connections are made.

Now, I did remember that when I was pulling the LIM the manual, said to pull the clamp off the fuel line from the primaries to the secondary fuel rail (front side of car) and pull the line off the nipple...that clamp looked pretty permanent (crimped on). So I pulled the bolt out (the one with the hole in it, that attaches the fuel line to the rail). So upon reassembly there was no spec on how to install that bolt...I just tightened it and tried to make sure the hole lined up with the hole in the ring (don't know if that even mattered)

Also, I didn't pull the fuel rail off when the car was apart, and when my injectors came back, I oiled the O-rings and simply dropped them back in.

I believe that's where my problem is...secondaries are not getting the fuel they need. Car is fine under light load and idle, but can't rev past 4k under 60% throttle. Any advice on how to troubleshoot secondary fuel system...pressure? installing that bolt? testing injectors? (I put a screwdriver on the top and listened while reving...couldn't tell)

I'm pretty sure I'll have to pull the UIM off again and probably the fuel rail...but maybe someone has a better idea.

You guys have been a big help (keeping the hope alive also), thanks

 

If the moon controls the tides...

 

Just bringing it back...hopefully some people responding in the Teenage knocking thread would like to help someone that has a legimate problem...

Anyone that has pulled the LIM off, please give some insight on the bolt (secondary fuel rail) I mentioned (up two posts) I couldn't find spec instructions in the workshop manual.

 

Just to keep this annoying tilted thread hanging around to let everyone know I not having fun boosting around in my FD...

Talked to one of the only mechanic shops (I've heard good things about) in ATL that does (NP) work on rotaries, and it seems I've installed that bolt I was talking about correctly...so now my problem is???

Dear Mods,
Close this thread, please...so I can stop talking to myself.

Thanks,

Carson

 

help this guy out!!!!!

 

Damn, I wish I could help, but I'm all out of ideas.

 

Appreciate the help guys, the more I troubleshoot the more I learn about the car; so at least it's not a total loss.

Latest thought "Fuel Pump Relay (Speed)", it's the one closest to the front of the car. Thought maybe there was a problem with it, so I pulled it and wired it the battery (terminals A & B) and I hear the click and terminals C & D show 0 ohms. This means that when the ECU tells the relay to operate it "should" and then the fuel pump "should" be running on the battery voltage (high speed) instead of the fuel pump resister (I couldn't tell from the picture where it was so if someone could point it out it will make the lesson more complete) which is low speed. I started the car warmed it up at idle without the Fuel Pump Relay (speed) connected, and then jumped terminals C & D in the relay box (as if the relay had been tripped), to run the F/P on high speed all the time. Thing is, I didn't hear a change in idle at all...I don't know if there is suppose to be a change but I would think that if the F/P was on high, the idle speed would get bogged or the exhaust would pop excessively or something???

Just for SAG (***** and giggles), for those who don't know...

In conclusion, when the primary injectors are operating the F/P is being powered by the F/P resistor which gives the speed LOW. At high speeds or heavy load, the F/P relay (speed) is tripped and shorts out the F/P resistor and powers the F/P with the battery voltage which in turn gives the speed HIGH. This is the only time the secondary fuel injectors are in operation.

I need to investigate the matter more... how can I test to see if the secondary fuel rail is getting fuel...or is it getting fuel the whole time, since its connected to the primary fuel rail? I guess I'll find out when I pull that bolt out and spill fuel all over the place again. Off hand does anyone know what that green connector on the sec. Fuel rail is for (the two red ones are the injectors but then there is a green one)? I don't have my manual at work with me...I bet that a good thing, though.

Air Bleed Sockets, could someone tell me about them. Like I said previously I didn't pull the fuel rails, I just dropped the injectors back in...could something get screwed up with them by doing that?

Maybe a good friendly rotor community thing to so would be (if someone could) go out to your car pull the Fuel Pump Relay (Speed), and warm it up...just joking.

Please anyone answer any of the questions you can pull from my ramblings...if you don't I'm sure I'll answer them all in the next troubleshooting session or two.

TIA

*edit* puncuation (sp?)

 

I think if your car is running, your secondary fuel rail most be getting fuel, since the return line comes off of the fuel pressure regulator, which is located after the secondary rail, and then it goes back to the tank. I believe you said that you were getting fuel out of the return line? Are you sure you have the fuel lines hooked up correctly (you didn't switch the feed and return lines?).

The green plug on the secondary rail is the fuel thermosensor.

I believe the air bleed sockets help atomize the fuel before it enters the combustion chamber. I don't think you could have screwed those up if you never removed them.

When you bypassed your fuel pump relay, did the car still not have any power after 4k rpm?

 

I didn't state that I was getting fuel out of the return line...didn't check, must be though since the car runs (could be wrong). I don't think it was possible to switch the feed and return lines...one bolts to the front side of the rail and the other clamps on the firewall side, right?

Thanks for clearing up the green plug and air bleed sockets.

After I bypassed the relay I still can't rev passed 4k...holding 60% throttle it revs to 4k and drops a bit and revs to 4k, etc. So as far as power is concerned I don't know.

Question of the year:

What can put my car in some sort of limp mode with NO codes being thrown???


Next thing I'm going to do is put the FPR SV back on (which I broke upon removal)...it's the only thing I can think of affecting the fuel system, but don't know why it would put me in limp mode?

Anyone have a FPR SV or secondary air injection (switching SV) they'd like to sell/donate? (didn't one guy get a twin turbo donated???, the T-shirt air filter guy???)

 

You broke your FPR SV? Do you know how it works? I'm not really sure myself... from my understanding, as you build boost, the FPR increases the system fuel pressure to compensate.

About switching the fuel lines, there are three rubber lines that plug in just below the throttle body. One of them (goes to the 'catch tank', whatever that it) is too small to screw up, but the other two, the feed and return lines, are the same diameter and could be put on backwards. But if you didn't disconnect your fuel lines there, then you have nothing to worry about.

 

My understanding...

FPR SV, aids in hot starts. increases fuel pressure on a hot start (and 90 sec. after) to avoid vapor lock.
(some chime in if I'm wrong)

Yes for every psi of boost the FPR "allows for" or regulates another psi of fuel pressure. 10psi of boost = 50psi of fuel pressure. My FPR is hooked directly to the LIM to see boost.

I haven't seen any problems with hot starts however, I haven't had the chance to run the car hard.

It's just the only other fuel related thing that has changed. So I'll change it back.

 

Man O man,

Finally another person with the same problem as me!! Im having the same problem with my FD EXCEPT: In neutral, i can rev the **** out of it just fine, but when i give it about 60% throttle, it stumbles and backfires..it will accell, but slow, and i smell fuel real bad. Ive checked for leaks, and I dont see any. in driving, as soon as the needle hits 0, the fun begins. it falls right on its face..but, i can get boost if i play with the throttle..it feels like something is sticking, or something. It will not hit boost under 3K rpm. But over 3K, i can ,manipulate the throttle, and edgine the needle back an forth between zero and -1, -2, I can finally hit boost, and it pulls hard. sometimes smoking tires at the top of the gear. i can shift, floor it, and it accless, and hesitates for a split second at 0, and hits boost again, but I always smell fuel when it stumbles..maybe a FPR problem? sticking? i havent tried bypassing the fuel pump relay cuz i smell gas. I dont get any codes at all, but when i unplugged the tps, I still didnt get any codes. I dont know if I can pull codes off of a japanese FD like the US cars do. But, ill be following this thread. Also, my cruising rpms flux up and down a lil bit, like its missing every couple of seconds. i get on the gas, it goes away. maybe a tps problem? ive checked the resistance, and it checks out. i also get alot of popping in the exhuast, accompanied with a dip in the rpms. unless i turn on the lights, or the AC, and it goes away. I have a DP, and a catless exhaust...I'll follow the thread and see what we can come up with.

 

onefastrx7turbo - I take it you are running Non-seq. Since you responded in this thread. But then you say no boost under 3k (well not much if any)...Non-seq won't see boost under 3k unless you've got some upgraded twins.

smelling fuel doesn't sound safe...hope you have a fire extingusher.

maybe FPR or FPD