hondahater

iTrader: (2)

well actually what I was thinking was cool was this

"So now answer this question: Yesterday I decided to set up the KNOCK sensor on the SAFC. Followed the instructions to the letter. So someone tell me what I am to look for when I'm driving uphill, full throttle in third and forth gear? I mean say I have the SAFC right there up on the dash with only the KNOCK showing on the display. When/if the engiNE knocks, what will the display show?"

I would like to know how to do that! do you have the safc blue screen with buttons or the newer black screen with a ****??? Thanks.

WAYNE88N/A

Rex- actually, there has to be two grounds, because there are two distinct shields in the circuit, and it doesn't form an electrical loop. The circuit breaks at the front-to-engine harness connector, under the trailing coil pack area, the shield doesn't "hop" the connector...

Yes, Honda Dude, I knew what you were getting all excited about

phinsn98

iTrader: (2)

Wayne,

Yeah I would say I've been doing a lot of research and tried things that have made sense to no avail. I have to say that I'm lucky in one sense my buddy has a lot of the parts that we've tried so as far as expense is concerned there really hasn't been. It's just been time and frustration. I'll be pissed if it turns out to be the FPR. We've kept saying that it is going to be something really stupid and easy. It's just a matter of pinning it down. As far as the when it occurs it's exactly like yours. As far as when I get it I can't pin it down. Sometimes I don't feel it and sometimes it's worse then others. It varies. The odd thing is that the fuel pressure is normal. I'm not sure how to figure it out since it's intermittent. The car has started to detonate at big load in fourth. I had to turn the boost down. I've never had a problem with detonation in seven years with this car. I'm wondering if the FPR not working properly could cause this. (I would think so)

WAYNE88N/A

Well, phinsn, if I remember correctly, your problem started soon after the FPR change, correct? Logical troubleshooting should have put the component replaced at the top of the list, if problems soon follow. Was it an OEM replacement, or aftermarket? Good thing you have "spare" parts with which to troubleshoot, I don't have that luxury. Then again, I've been troubleshooting electrical systems for half my life now for a career, so I fully expect to find the bad parts without "throwing parts" at the problem. The fuel pump I changed shows how confusing it can get at times, but at that point it was down to the pump & FPR, and anybody that's been doing this for awhile would have guessed the pump first- more complex part/ more moving parts, versus the FPR, basically a spring and poppet. I did realize after the fact that I could have blocked the fuel supply had I had a fuel pressure gauge, and nailed the FPR that way. But what the hell, the pump was 17 years old anyway, lol...

When you say the fuel pressure is normal, are you getting actual readings off of a pressure gauge? As far as the detonation, that of course would be the result of insufficient fuel, and I thought you said you were running rich?

I'm fairly certain at this point it is the FPR- she started to behave again after I cleaned and "beat it up" a little, and I touched nothing else on the car that day...

HAILERS

****I would like to know how to do that! do you have the safc blue screen with buttons or the newer black screen with a ****??? Thanks.****

The Super AFCII, round **** thing. I also have a Super AFC with the buttons. That one does not have a Knock feature.

After driving around I have discovered how it works. It reads zero. Then you hit a good bump in the road. Now it reads 1. Hit another bump....2.....it counts bumps in the road. Either that or I need to rid myself of these Tokico hard **** shocks so it can count KNOCK. I believe there is a fsm method of striking a hammer close to the knock sensor and checking the timing to see if it retards. I might try that. TAke the hood off, have someone drive the car, and sit on the fender and strike the housing with the sensor. humor

WAYNE88N/A

So what you're saying is you have a computer that tells you when you hit bumps? I can tell you from experience that my car tells me when I hit bumps without any of those fancy gadgets

I could probably post the instructions, a little "how to make your car tell you when there's a bump" type thing, just in case you have no nerve endings in your *** or something...Heck, I could even start a business, selling "modified" FPRs that would do the job well enough...

WAYNE88N/A

Well hell, gotta drag it back from the dead. Was hoping this would be the final update, but...

Finally got the new FPR in, and she seems to run smoother now overall, but she's still having trouble on the bumps. It's about as bad now as it was when she first started this crap two months ago...

Next thing to do is go with Hailer's theory about the O2 sensor, because the output from that little guy is slightly more erratic now than it was with the old FPR. The sensor is only about 2 years old, but maybe the Bosches just can't handle the rotary's heat like the OEM units. So Hailers, let's hope you're actually right this time, because if it ain't the sensor, I'm looking at the ECU, harness, or injectors. All of the input sensors looked good a while back, so they're out of the picture for now...

White_FC

Hmm. Sorry I havn't read this WHOLE thread.

But try just diconnecting your O2 sensor..

Because I certainly didn't have any sort of mis-fire when I had mine disconnected.(header without spot for one)

WAYNE88N/A

It's not really a misfire, WhiteFC, it's more like the fuel rail pressures go down for maybe 1/2 second, resulting in a slight loss of power. She's not bucking, or really hesitating, in the common meaning of the word... And the freakin O2 sensor shows it, while it's happening, it definetly shows the engine leaning out for a bit, then she'll "richen" back up and run normally again. The entire fuel system that controls the pressure has been changed now...And that reminds me, lol, I did disconnect the O2 sensor, I forgot all about that (and she ran the same). Shows how long I've been troubleshooting this biatch, I'm forgetting what all I've checked, lol...

Damn, now I don't know if I want to change the O2 sensor or not...It certainly appears to be doing what it's supposed to be doing, during all facets of driving, even the bumps, lol...

The maddening thing is, she ran great for 3 or 4 days after I cleaned & beat on the FPR. I mean, what would any sane person think at that point? FPR, right? Not that I'm even close to sane...

I'm gonna spend a couple of days reading out the primaries, to see if I can get a twitch out of those guys, thoughI think I've already done that too, lol...

I think the whole thing is just the Man upstairs letting me know I'm not as smart as I think I am, lol...And He's getting a kick out of it

hondahater

iTrader: (2)

man that sucks *** the expensive fpr didn't work! I'm trying to think of anything it could be but if you've changed everything then the only thing left would be ecu or something in the fuel line???

WAYNE88N/A

I know, man, I celebrated too soon, lol...

White_FC

So your SURE the fuel pressure is falling when this happens?

Really sounds like a loose connection somewhere dude.

Checked out the connections at the pump? The AFM switch? all the relay contacts? the entire wiring harness?


Ie, it coule be anything..

WAYNE88N/A

I'm not sure about anything at this point, lol...

Either the pressure is dropping, and the O2 sensor is showing it correctly (the theory I've been working under so far)...

Or, the pressures are fine, and the O2 sensor (or SOMETHING in the fuel scheduling electrical scheme of things) are "hiccupping" their input signals on the bumps (the theory I'm going to now, lol). Problem is, everything looks good at the ECU while driving (AFM, TPS, water thermo, temp senders, etc)

Looked at the pump connections when I changed the pump. Saw no physical abnormalities, though that's a good idea, I should read out the pump voltage while driving too

I've even wondered whether it might be the circuit opening relay contacts seperating a bit on the bumps...Need to jumper it to troubleshoot that. That's a good idea, too...

Quit scaring me with this "entire wiring harness" scenario, lol...

HAILERS

Welllllllll, try this. Disconnect the 02 sensor from the ECU. I'll let you keep on monitoring the 02 sensor output with your meter though. Now go drive it around for a couple of days. Ask yourself "Is it bettter". Be sure to write back. P.S. I never ever thought it was the FPR. I still think it's a 02 sensor input problem.

By the way. Take a meter, preferably a digital meter. Put one lead on the 02 housing and the other on the intake manifold. Put the meter on ohms. Turn the meter to ON. How good is the reading? Dispite the bolts that hold the exaust pipe on to the exaust manifold, I've seen high resistance on this combination in the past. Mostly on a turbo though. I know not exactly why. Maybe a ground strap to the exaust as is seen on the original config? Just a thought.

WAYNE88N/A

Well that was a damn good idea, Hailers...So I promptly went out to the car and checked the O2 sensor to chassis ground. 0 freakin ohms, man, surprised even me. Figured it would have at least SOME resistance...

BTW, people that know how to read meters don't require digital ones

I've ran the meter lead back to the fuel pump connector at the strut. For some reason I can't get the "circuit opening relay contacts bouncing" theory out of my head, so I'm checking out the voltage from that sucker on the way home tonight...

HAILERS

Waaaaaay back at the beginning of this thread I mentioned the 02 sensor and my past experience on long drives. I knew it was the 02 sensor because I had at that time one of those code devices with the two LEDs running to my dash. The light would blink when the hesitation happened. Speed the engine up for a mile or so and it would go away and not come back for some time. So what I'm saying is, is that if you have one of those code breaking LED light assy's in your car, and not seeing the 02 code when the hesitation happens..............then forget anything I said about 02 sensor being the problem.

Zero ohms? Goody for you. By the way...how are my smart *** remarks coming along???? Think they'll ban me from the forum?

anobii

Gosh I cant believe I found a thread with the perfect content on the first try.....I must be getting better at searching -yay-.

wayne, I am having almost, if not exactly, the same problem....only mines more severe.

Here's my variation. While cruising, at any speed and any rpm, in any gear, when the engine reaches what i like to call it's minimal load point... (where the accelerator is held in one posistion, and the engine is loaded just enough to keep the car moving at a constant speed on level road- where the A/F gauge usually bounces in the stoich range- I guess this is closed loop?)....Instead of reading stoich, it goes lean, like scary lean and skips and bucks ever so slightly. The thing here is, if slightest infantecimal amount of pressure is applied or unapplied to the accelerator, boom, A/F goes to it's normal rich posistion, hesitation is gone and power is gained, But it will come back when the pedal is held in the same spot when cruising. Basically our problems are the same they just happen under differant circumstances. It's like it's loosing fuel pressure or ecu signal to the injectors.

I just recently replaced all of the gaskets on the intake/exhaust/turbo, as well 100% of all the vacume lines with silicon. I had the injectors cleaned and flowtested, tested the FPR while it was off, and totally reloomed and inspected the wiring harness. There is zero emissions left, aside from the BAC, and I put a FMIC on it. I had this problem (among others) before I did all of this, and this is the only problem that remains. I've checked all of the stuff you and others have mentioned, to no avail. The only two things that stick in my mind that I am unsure of is: 1. the vacume source for the FPR, and 2. I remember that one of the solenoids on the vac rac controlled or switched vacume to the FPR, if you still have all of your emissions, maybe this solenoid or the wires going to it is/are malfunctioning, and mines no longer there. I read that this had no effect, and was okay to remove, but it is very possable that I was misinformed.

If you can put a "T" in the vac source to the FPR and run it to a vacume gauge inside the car, and moniter the vacume when the hesitation occurs, it might tell on the solenoid.

There's your long shot If I come up with anything in my efforts, i'll definately post it here.

BTW is your car an S4 or S5? mine is an S5.

-E

RETed

Yours sounds like a TPS problem...


-Ted

WAYNE88N/A

I've been meaning to update this thread for a couple of days now, and since it's popped back up, now is as good a time as any, lol...

First of all, Anobi, it's not hard at all to read your TPS from the ECU while driving. If you see the meter "hiccup" while you're hesitating, you nailed her. In fact, it's not hard to read anything at the ECU, and I'm on the second round of going through everything again, just in case I missed something the first time, lol...

Yep, almost exact same symptoms. Almost always at cruise, O2 sensor slowly goes lean (while still in closed loop, which is kind of weird watching the meter bounce back & forth, yet continually get lower). Other times it'll just drop to 0, then any little bump will start the crap again. Almost never happens on a smooth road, even at 125 mph+. And when the engine is hot, she'll do it going down my bumpy-*** driveway in low 1st gear.

At this point I can tell you what it's NOT: So far all of the sensor inputs to the ECU look good, never got a single twitch out of the TPS or AFM, which were my prime suspects in the beginning. Turned the AFM back to a 90* orientation (which is where I had it after the cone filter install)- no change. It's not the fuel pump, FPR (although on average she's been running better with the new FPR), or the pump power circuit. It's not the rad temp switch. It doesn't appear to be the injectors, there are no hiccups there, either. Grounds are perfect...

I'm going to replace the O2 sensor today, even though the unit on the car is only 7 months old, and it looks like it's working. I hope Hailers is right for once, lol, because I'm fixing to start rewiring the damn car...

I've rerouted the vac around the pressure reg control solenoid, thinking it might be clogged or broke internally, which would be affecting the vac pressures at the FPR. I'll test that one out driving to get the O2 sensor I ordered. I'm also going to look at the variable resistor inputs, and the atmospheric pressure sensor inputs at the ECU, I think I skipped those the first round of checks because they didn't seem likely suspects...

Mods- we need to retitle this thread to include the words "hesitations at cruise" so any future searches may pull it up...

anobii

I had a thought, is there anyway to disable the closed loop? I'm assuming it has something to do with the transmission switches, at the very least it would alow me to drive drive the car without fear of causing damage, unless it has nothing to do with closed loop and is just a coincidence it happens when while it is in closed loop. Might be another thing to trouble shoot.

The TPS on my car has been adjusted to 1 volt and once to 1 ohm, even though ist's not supposed to be done either way. But i don't have the vac rac anymore so there is no solenoids to activate the led's. Anyway I checked the narrow and the wide with an analog multimeter through the full sweep several times, no jumps or dead spots, just as smooth as can be.

-E

WAYNE88N/A

You can disable closed loop by disconnecting the O2 sensor plug. I tried this a while back, and it didn't help me out any. Which is why I ignored Hailers for so long about changing the O2 sensor

All right, Hailers, the O2 sensor is changed. Didn't solve a damn thing, except make my wallet $37 lighter, lol...I told you it was doing what it was supposed to be doing

It's not a clogged pressure reg solenoid valve. It's not a clogged purge valve. It's not the variable resistor. Checked all that stuff today...

I think I'm on to something, though...The EGR blockoff plate is leaking a bit, found it by spraying contact cleaner around it during idle. Spooged some more RTV around the edges, but you can imagine how hard it is to get to with the UIM still on. I'm thinking that the exhaust gases are periodically blowing by underneath the plate into the intake (when she warms up), from passage to passage. That would explain a lot of things, like the running lean (as seen on the O2 sensor with a meter).

Now on to a true engine guru question- instead of pulling the UIM (which I don't want to mess with, because she's been leak-free since the rebuild & new gaskets), is there any way to block off an easily accessed passage to prevent the EGR gases from being sucked into the intake passages? In other words, where do the EGR passages go from the origin points that sit under the EGR valve? Do they hit the intake runners in the center housing (my guess)? Do they go out to the ACV at all?

WhiteFC- you're good at tearing things up- why don't you tear your engine down so you can get me an answer, lol...

White_FC

Well funny about that, I happened to have rebuilt my engine twice now (thanks to a dumb **** problem with the first time.. )

IIRC, The passges _from_ the exhaust basically come up through the center iron after passing through the ACV(pretty sure on this one) then gets distributed into the intake runners via the EGR valve.


If you have a leak at the EGR, that could cause a hesitation for sure, leaking vacume will do that to you...

WAYNE88N/A

Yeh, that's about the way I remember it too, it's only been 5 months since the rebuild, but old age and too much fun in high school pretty well have the memory cells wiped out, lol...

Yeah, the ACV has the little exhaust check valve thingy, right? Is that coming FROM the rotor housings' exhaust port passages? I always thought that was going TO the rotor housings, for the port air injection from the ACV. In that case, it wouldn't work to block the check valve off...

I wasn't sure if the ACV had anything to do at all with the EGR passages or not...

In any case, if I can't do it there at the ACV, next weekend I'll tear the UIM off and reinstall the EGR valve that I removed during the rebuild, after blocking the passages on it- it's much thicker than the block-off plate I have on there, so won't flex as much...Plus I still have a new gasket for it from the rebuild kit

That's my new theory- the aluminum block-off plate I have on there now doesn't have the same thermal expansion characteristics as the iron housing, so it's warping between the attach hardware, causing the exhaust passage to flow into the intake passages unimpeded. And it took about 6K miles for the red RTV to break down enough for it to start doing this...Don't know why it waits for a bump to do it, though, lol

anobii

You mentioned the purge valve (the vacume pot right behind the oil filler neck?) Would this cause a problem if it was no longer there, and the nipple on the center iron capped? I didnt even really think about it when I did it, I just assumed it went to the same place the oil filler tube went. I know, assumtion will get you in trouble.

Your beyond what I can do, my S5 t2 didn't come with an EGR valve. The FPR on n/a's must be easier to get to than on turbos. I have to take the UIM off just to see mine.

Logic tells me that my problem is electrical just by the way it only does it when it goes into closed loop, and how small the amount of pressure has to be applied to the throttle to clear it up. I'm off tomarrow and will have most of the day to mess with it, i'll let you know if I find anything.

-E

WAYNE88N/A

The purge valve is part of your evaporative emission system, and vents "crankcase" vapors back into the intake. It opens the passages and allows this anytime you're over 2,000 rpm, which means it's almost always open. I checked mine because it was something I hadn't checked yet, and I have damn near checked every electrical component on the car, so I'm looking at the vac system now (which is how I found the EGR block-off plate leak)...

IIRC, most guys that remove that valve need a catch can for the vapors/liquid that need to be purged while running. A search might pull up some more info for ya...

And no, the EGR location is just as much a PITA to get to on an NA, lol (sans the TMIC)...

Yours almost sounds like what Hailers was talking about when he had a similar problem, which turned out to be the O2 sensor. Easy fix there