Red Dead Racer?

[spiffyguido]

One more thing I remembered.

In the 3rd gen manual it listed a procedure for testing the EACV that includes ohming out the EACV itself. I looked in the 4th gen manual and couldn't find a similar step in the trouble flow-chart.

For the 3rd gen, one way to test for a defective EACV is to measure the resistance across the EACV's two electrical prongs. If the resistance is outside the range 8-15 ohms then the coil in the EACV is broken and the unit must be replaced. After scouring the 4th gen manual for a similar spec I came up empty handed. If you have a multimeter handy, it wouldn't hurt to measure the resistance across the EACV and see if you get a reading. I doubt Honda changed the design of the EACV much between 91 and 95. They've been present on every Honda engine since the early 80s and all seem to look about the same.

[RedRacer]

Embarrassed to admit that I had to ask that question.......but there are so many conflicting articles and stories where the IAC and EACV are referred to as the same. I know the IAC, infamous culprit of rise and fall idle) but have not really dealt with the EAC.

I'm going to pull it off this afternoon and clean it up. Tempted to just stick the cardboard in there anyway. Fingers crossed. I really hope this resolves the problem either way; cleaning or cardboarding it.

I just need to know this is the problem and not something bigger and more hidden. When my Prelude isn't running, I feel so disconnected and depressed.

I'm not going with the TPS yet. In my experience I've not seen many, if any of those fail unless they're actually damaged. BUT -- getting water inside might be a different animal.

What do you think about hooking a bottle of SeaFoam up to the PCV hose and running it through the vacuum system. Bad idea or good idea with that stuff? Never used it other than in the fuel tank.

I was thinking about the voltage issue as well to see if it's actually failed or not. Will check on that too.

[spiffyguido]

I wouldn't let seafoam go near anything outside of your combustion cycle. It's designed to free up carbon deposits and is a solvent. Who knows what it might free up if you set it free in your vacuum system with your sensors. Not something I would do.

I hope giving the EACV a cleaning will help the problem. Its one of the sensors that can fail without necessarily triggering an ECU code.

Fingers crossed.

[RedRacer]

Removed and cleaned the valve. Sprayed a little WD-40 inside, hooked it back up, didn't lose any coolant, didn't bother with bleeding. Cranked it up and drove out, bogged before I got to the end of the drive. Took it down the street and it was the same symptom, only worse. Almost didn't get it back home. Once it was up and running it was like a rocket of course.

Got back in the garage, bled the coolant just in case, pulled the valve off the plenum and put a piece of cereal box in between to cover the two ports. Screwed the valve back on and took it out. Same thing.

I give up.

I might tow it to the mech on Monday. I might just let it sit.

Money is tight right now and my patience is even tighter. Pretty sure it's something to do with the water in one of the valves or sensors. Just not knowledgeable enough about it to track it down. And I don't want to just start throwing parts at it.

I don't think it's an internal issue. I really don't. I do know engines and I've never seen one act like this due to a bent rod, etc. Cylinder misfires, vibrations, bad compression and all that, sure.

The engine pulls strong as hell once it gets past whatever is hindering it at the beginning. So I just don't think this is engine damage.

[spiffyguido]

Dang. I was hoping that would help.

The EACV might be damaged. Mine was completely hatched when I replaced it.

I agree that the issue isn't mechanical. You've just got some gremlins to work out.

[RedRacer]

Update : OK - so, seeing Red in the garage gathering dust and not being driven or looked at was killing me, of course.

Today I fired her up and rolled her out of the garage and let her run idle for about ten minutes. Before doing this I pulled the connection for the EGR valve. Drove out of the drive and got the same sputtering, backfiring, and lurching. Just put my foot into it and got high revs and was able to get it moving. Got down the street and up and around the hill without any real problems. Power loss was there but nominal. Finally the check engine light kicked on because I had disconnected the EGR valve. Once that light came on, the engine issues all but cleared up. AWESOME!

I drove around, AC on, 99 degree temps out, stop and go traffic, no issues. A couple of slight hesitations and stutters at lower steady speed rpms, but nothing that concerned me. Had a couple of stalls at red lights when rolling up to a stop. Started back up no problem. AND this is with the idle screw at maximum idle setting. At that setting I'm barely getting an idle of about 750 to 800 rpm. Should be much higher with the screw set all the way out.

Turned the car off and ran an errand. Came out about 20 mins later. Cranked it up, same sputter stutter spit backfire but was able to drive with keeping the rpms up. Drove in stop and go traffic and had to run the rpms up to keep it moving, but as soon as the CEL came on, everything cleared up. Ran almost like normal.

All was going well. I'm stoked because I'm seeing an obvious correction due to my disabling the EGR valve and allowing the car to shut down the EGR system and throw the CEL. ..... then, after sitting in a drive through line at Chick Fil A for about 20 mins to get a side-salad and a grilled chicken finger, it started stuttering and lurching out of the lot, with the CEL on. DAMN IT! I was so mad. Totally blew my theory... so I thought I was back to square one again ..... BUT - it cleared up once I got on the road and ran the engine a bit.

Then as I was going downhill and had a light throttle applied, I got a slight drop-out, hesitation. And it kept doing it at that throttle position while running downhill...... so, I shut the engine off and then turned it right back on while moving -- CEL went out, then the bucking and crazy ride started. Could not get the CEL to come back on and I barely made it home. Live in a very hilly neighborhood and I started smelling the lovely fragrance of burning clutch plate as I was revving the holy hell out of the engine and slipping the clutch to try and gain forward momentum to get up the hill and home. I was going to be damned if I was going to get all that driving done and think I figured out the problem, and then have to bail out half a block from my driveway because I couldn't get it up the hill. Got it in the garage, MAN did she smell hot and burned! I hated that I did that. ...... turned her off. Will try and experiment again tomorrow.

SOOOOOOOO- Apparently the problem is within the EGR system. I believe the ports need to be opened up and channels cleaned out.....and probably replace the valve as well. I don't think it is just the valve itself...... but I could pull it off, clean it and see what happens. One thing we all agree on, this is definitely due to getting things wet that should not have ever gotten wet.

OH yeah, interesting thing as well -- sitting at the light without the CEL on, if I moved the throttle up above idle to about 1000 rpm, and held it there, I would get the "fast idle hunt" up to about 2500 and then drop down to 1000, then back up to 2500, and as soon as I let off the throttle and let it drop down to idle rpm, it would stay there at a steady low RPM. All related I'm sure.

WHAT DO YOU THINK SPIFF?

Once again, here's hoping.... At least I'm closer to knowing and getting a resolve to the problem.

[spiffyguido]

The good news is that I think we can rule out anything being mechanically wrong with the car. The engine sounds like it's working fine, but you certainly have a sensor or two completed buggered.

When the CEL light comes on, your car reverts to 'open-loop' operation. This just means that it ignores some of the sensors and instead relies on its internal fuel tables to meter the fuel. I've found this to be a useful trick on numerous occasions. Quite often, a failed sensor will knacker the driveability of the car, so you just go under the hood, pull out random sensor (I usually choose the coolant temp sensor, because it throws the CEL immediately) and then drive home.

You basically used this same trick with the EGR. The problem we have no is determining if the problem actually is the EGR system or something else. Even though the EGR is tripping the CEL, it doesn't mean that it is the sensor to blame for the running problems in the first place. My top picks at present are: EGR, EACV, MAP and TPS.

I don't really think the TPS is likely, because it still sounds like your car is good at responding to throttle input, so rule that one out for now.

MAP is a possibility because it does impact fuel metering and because it has a vacuum line it would be susceptible to water damage. There's a testing procedure on page 11-44 of the manual. Electrically speaking, it's a simple sensor, but if water got in it I'm sure it would be ravaged.

We spoke of it already, but I'm still suspicious of the EACV. This might mostly be due to the fact that I had bogging engine problems when mine went bad. Some of what you describe sounds all too familiar, especially the part about having to keep your foot in the accelerator to get anything out of the engine at all. Again, full throttle == open loop on a Honda.

EGR is still on the menu as well. I've never had to test one of these, so I'm not sure where you can start. See page 11-135 for some info. You'll need a vacuum pump to test it, that's for sure.

Can the MAP be opened on your car (ie does it have a lid?). If so, I'd crack it open and make sure it doesn't have any tadpoles living in it.

Stay on this. You'll get her fixed. Mechanically it sounds like all is well, even though your clutch plate probably smells like burnt toast right now.

[RedRacer]

Going to check the MAP, see if it can be opened.

Going to reset the ECU and then do another drive with the EGR disconnected.

Going to pull the carpet up on the passenger side and see if there's any sign that water got in down there. I just don't think it's the computer though, (the reason I am checking is because that's what my mechanic said it sounds like to him) because there was never any sign of water in the floorboards of the car.

The inside of the car does smell strongly of mold now - wet car smell. So it's possible that water got in but not enough to get through the padding and up into the carpet....... but enough to screw up the computer.

Not going to worry over it this weekend...... but will start checking on things soon.

May be that the computer did get wet after all ? BUT -- if it got wet, then why didn't it fail immediately? Why would it stop working a week later?

Mechanic says, like you, that when the CEL comes on, the ECU goes into backup mode, and like you, said that it doesn't mean that it is the EGR that has failed just because it's triggering the CEL.

[spiffyguido]

I don't think the ECU would up and fail a week after the incident, but it might.

If you do end up needing an ECU, let me know which one you have (see code on ECU). I may have a spare.

[S-LudeDan]

Hey Red Racer! I think I saw you on youtube teaching the spark plug DIY. Very cool tutorial. I accidentally bumped into that vid lol.

[S-LudeDan]

unless it was Spiffy

[spiffyguido]

'twas Spiffy...but credit to RedRacer is due thanks to all that I learned reading his posts whilst we were both mods at the late HPOA dot ORG website.

Speaking of Red, I think it's high time this thread received an update. What's the status of the 'lude, RedRacer?

[RedRacer]

Thanks for the comps -- but ultimately I deem you THE Honda Prelude Guru of Knowledge. No doubt.

Well, yesterday (today as I write this) is, believe it or not, two months since "The Flood". It was on the 13th of July that I decided to drown my Prelude.... lessen learned? > PRELUDES DO NOT MAKE GOOD BOATS OR SUBMARINES.

Current info -- I fired her up this afternoon, let the engine run idle up to temp for about 15 mins, jumped in and headed out and got the stammering and stuttering I've become used to -- after the check engine light fired from the EGR being unplugged, she still acted up a bit, finally got a good backfire in the throttle body and she ran pretty good for the remainder of the afternoon. Not as smooth or powerful as without the CEL being on -- but not jerking or bogging down.

Parked her at a friends for the evening, from about 4 until about 9:30 -- warmed her up and headed out, jerking and bogging, but the CEL never came on and the whole ride home was a nightmare. If I could have driven at 80 mph without any cars in front of me or signal lights to stop at, it wouldn't have been an issue -- However, I was able to make it home just by keeping the throttle heavy and not allowing too much time in the 2500 rpm range. Last time she barely was able to pull the hill on my street to get to my driveway -- didn't seem as severe this time. So, go figure. That's the biggest issue here, ZERO CONSISTENCY and the symptoms. Can't get it to do the same thing over and over/repeatedly so I can validate that it's "THIS", so I can then fix the problem.

Why so much time has passed? Because I've not felt like dragging her to the shop and having the mechanic try and figure out what is going on -- been to busy for one thing, and I am also not prepared to start throwing money at "diagnoses-ess" that replace parts that aren't broken and end up having the problem still be there.

I found a good site on Ebay with a ready supply of EAC and IAC valves. I am going to go on your advice Spiff and order one each and replace the old ones with two new(used) valves and see what happens. IF, (and that's a big IF) it does solve the problem, I will personally drive to Alberta and kiss you on the lips! lol

Will let you know what happens, when it happens.

[spiffyguido]

Arrgghh....the 'zero consistency' thing makes problems like this untolerable. I feel your pain.

Slapping on some used EACV and IAC valves is a good move. You may as well verify those before you go digging deeper into the electrics. I'm still quite hopeful that the EACV might be the source of your troubles.

We're all watching with great interest.

[RedRacer]

Still haven't done any major decision making on the Prelude. I drive her on the occasion to my office or around the neighborhood. As long as the check engine light trips and the computer is shut down, she's normal as can be....... but hell to pay if I can't get that system to trip up the computer and shunt it.

Here's what's funny -- that car is/was such a part of my life, you wouldn't believe the dreams I have about driving it! Constantly in my dreams and running like a top! Last night I dreamed I was driving in her but it was right hand drive. I kept getting pissed off because I couldn't make the stretch across the dash to reach the sunroof switch that was still over on the left hand side! LMAO.... How funny is that?

Sometime soon I will do something. I promise. In the meantime, know the car is in a clean, dry garaged environment, sparkling clean and not being allowed to rot away or anything tragic like that.

More news when there is some.