MAD_MIKE

* The search function appears to be s.n.a.f.u. So here I be... starting an unnecessary thread... like a muppet.*

1995 EX coupe. F22B1/AT

On a short on ramp while flooring go pedal the engine revved to 4Krpm at about 4250rpm it sputtered and misfired through the exhaust. Just like a rev limiter. AT upshifted to 2nd, same thing happened 4250rpm misfiring and sputtering. Up-shifted into 3rd and 4th no problems, did not reach that rpm in those gears as that is ludicrous speed. Manually shifted to verify it was not a transmission issue, and it appears to be solely an rpm related event.

Oil is full.
Transmission is full.
Timing is correct base.
Checked trouble codes, none stored/no CEL light. Light is functional at start check.
Fuel is below 1/4 tank, but I have never had issues before.

Strangely enough the temp gauge is working today, it has always been finicky.

IIRC if oil was low VTEC would not kick in and the engine would be limited to 3Krpm.

So without the aid of the search function I am at a bit of a loss.

T.I.A.

ReaperMan

if you have a voltmeter check voltages in tps. map. egr. while driving see what your voltages are, also check for vacuum leaks

NZXTInerTia

I was having issues like this awhile ago, replace the fuel filter because almost ever Honda with a motor over 150+ miles had had an almost completely restricting filter. The Accord's are also horrible for the sending unit accuracy, or as far as I've experienced. You were on a hill and perhaps adequate fuel wasn't reaching the strainer. My 2c.

ReaperMan

*palm to the face* how did i forget the fuel filter hahaha, after changing fuel filter check psi

chrisnick

Sounds like a clogged cat.

MAD_MIKE

Definitely not a clogged cat.

NZXTInerTia

Or check before AND after for ***** and giggles. What sort of ignition components have you installed/inspected? Your cap and rotor could be contaminated, or perhaps your wires worn out. I stopped following the update thread, I'll go read over it quick.

MAD_MIKE

That is a different car, '97 Sedan, the 4dr is fine.
Current issues are with the much neglected '95 Coupe, kind of the reason why I started that thread, so as to keep tabs on what has been done to the '97. Unlike the '95 where I stare at it sometimes and forget to check the simple items, or have to look at a scar to remember if I did in fact replace something HAH!


I didn't have my DVM, so I was unable to test anything tonight.
Mentally going through cause/affect.

I don't think it is the TPS as the problem initially happened at WOT. When upshifted to 2nd I rolled into the throttle to see if it was rpm or throttle. While in 2nd I never went to WOT, just right at 4250rpm it began to stutter/misfire.

MAP sensor would make more sense, but I can't see it 'just so happen' to be at the exact same RPM in both gears. Load would be different.

'Crank' sensor, I don't see why it would be faulty at a given rpm, unless it starts loosing resolution for some odd ball reason after 4K. In Park the engine revved freely, although no load.

EGR, I can't see it becoming instantly and severely faulty, consistently. It either works or doesn't.

Spark plug/spark plug tubes, that could be a culprit, if they are oil fouled, but again at the exact same rpm?

Almost wondering if the NM/NC sensors in the AT are doing something goofy, being they read shaft rpm only.

I'll put a few gallons into the tank and see if that changes anything, if it does then I know I probably clogged the sock or have water in the tank. Bah!

holmesnmanny

It's too bad you don't have same distributors or you could swap em. I would think this would be distributor related 'though. Given that it's not throwing a code...it would only throw a crank sensor code...amongst the many items in the distributor that could be the culprit.

First thing I would do if it was me would be to use the pull each spark plug wire one at a time trick. Even tho some people say it could cause damage if you do each one fast enough I've never had a problem doing it and it has led me to causes before.

MAD_MIKE

The more I think about it, the more I cannot recall how the gas gauge read. I normally avoid going below 1/4 tank as I don't want to ever risk overheating and having to replace the fuel pump. F-that-noise.

One thing I didn't mention, after getting home that ATF was down over a quart... da fuq? No leaks, now. There was a munched diff/axle seal that was replaced but that's not leaking anymore.

holmesnmanny

You're more the AT guy than me but I would think low fluid would just cause problems shifting not problems with revving.

For the fuel pump normally when these go they just stop working and that's the end of it.

chrisnick

I'd double check it. My Jeep would do pretty much what you're describing with the cat clogged. Cut it out, pulled great to redline. Might as well check it out.

MAD_MIKE

Yup > no fluid > no pressure > no go.
Filled up the tank and went for a spin held it in 1st and it did it again. But the sound and feel is that the transmission is trying to upshift and is grinding syncros. Kinda weird.
Or kick the hell out of the tank to get home. BTDT
I've had a couple of hand me down shitboxs and clogged cats in my day. None ever would just cut out. There would be a more gradual reduction of power, or inability to go beyond a certain rpm. This is clean rpm cutoff just like a rev limiter.

MAD_MIKE

An afternoon of, pulling NM/NC sensors, checking resistance and voltage output of various sensors, I was stumped. Pulled off the distributor cap found no yellow boogers or crud, although the cap did seem to have some kind of fine powder residue inside it. Halls effect sensor has some ferrous material stuck to it so I cleaned that off. Spark plug boots were dry and oil free. Hell, I even went to the trouble of unhooking every applicable electrical connector in the engine bay, looking for a bad wire or corroded connector.

Nada. Did not find a damn thing.

Started the car up, much smoother running and sounding, so maybe there was something going on somewhere, loose connector or dirt. Went for a spin engine had a bit more pick up, exhaust sounded aggressive too. Hopped on the nearest onramp and floored it...
3500>4000>4500>5000>
>rev limiter

Figuring I must have found or fixed a weak spot I went over everything once more, and found...nothing.


Put everything back together, futzed with the throttle cable adjustment, packed my crap and headed home.
Traffic was light, passed a few cars looked down at the tach 2500rpm, looked over at the speedometer 80MPH
Frack me.
The damn Tach is acting up.

FWIW;
BOYA trans will net 2700rpm @ 70MPH
MPJA trans will net 3000rpm @ 65MPH

I was seeing 2500rpm @ 80MPH, when it should be closer to 4000 rpm with the MPJA. Current conclusion is that the tachometer is reading on the 6cyl scale. Which IIRC 3750 is what I have seen for doing 80MPH.

When it shows 5K the engine actual is 7500rpm... so I was hitting the actual rev limiter? Has a friggin red stripe from 6-8K, and I usually stay away from that.

And the search function is still down...


Ugh, I really don't feel like pulling half the dash apart to get to this thing.

holmesnmanny

hey mike are you in Castro Valley ? I can shoot over for a few and take a look ...just pick me up a cold pack if i figure it out lol

im in milpitas now but i grew up in fremont and hayward(im assuming you're in castro valley or you probably don't know those cities)

MAD_MIKE

Was, just moved, need to update that location. I'll need the beer if I'm going to attack it myself Only problem is seeing if the tach is fixable or if I have to scrounge one out of PnP.
Heh, yeah I'm familiar. Moved to San Leandro, but from Oakland.

holmesnmanny

just reposting this...not sure if you saw it originally

Ok, I just seen your new post now. I think the problem is the icm going by that film you said you found inside the cap. I had the same issue before. I blew mine when I didn't remove the ecu fuse when I did my very first compression test before. The next time I started the car it ran for about five seconds then i heard a pop and found a white film inside the cap. Replaced the coil first then the icm and it fixed it.

You should check for weak spark. I suppose it could be the coil too. But I would just get another distributor from picknpull.

The icm is responsible for the tach signal. It should fix your tach problem.

MAD_MIKE

I was just looking at the techauto site and reading up on the ICM/Igniter but it seems like if it was faulty the engine would stumble. Currently I am positive there are no issues with the engine, and that the tachometer itself is faulty, or some circuitry in the cluster is. The engine starts and runs fine, even better now after screwing around with everything today.

EDIT: Tachometer is reading on the 6cyl scale. I've had GM vehicles that have a 'switch/plug' that becomes sloppy allowing a tach to read incorrect for the number of cylinders. Usually just requires resetting the 'switch/plug'

holmesnmanny

What exactly did the film look like ? Was it white ?

MAD_MIKE

It was a yellow powdery substance. Similar to the yellow 'boogers' that were on the '97s terminals. I'm guessing some kind of aluminum oxide. '95 had a tuneup back when the transmission was replaced around ~230K back in '09 and the car now has ~270K. I'm guessing it is just oxidization coming off the tower terminals that was coating the inside of the cap.

I recall reading about a faulty tach here on H-T but without the search function it's going to be a mother to find.

Next step was just to look online to see if the Honda Tach signal is compatible with aftermarket Tachs, or if I need some kind of signal generator to make it work. If so, I can easily tap into that wire and verify whether the tach signal is goofed coming off the ICM or if it is the Tach that is off.

chrisnick

Good to hear you pretty much got it nailed down. I'd just junkyard dive, rip out a cluster, and toss in the tach portion to see if it fixes it.

MAD_MIKE

Pulled the cluster out this evening the screws for all the gauges were loose, cleaned and snugged those up which seemed to improve all the gauges response. But no change in the Tachs reading. Still on what appears to be the 6cyl scale, which is a bit bizarre being that there is no visible switch, and according to Majestic there are different tachs for the 2.2 and 2.7.
Looking at the back of the circuit board there where the Tach attaches, it uses three screws...
...on the right there is a single screw, if you follow that circuit down under where the bulb is and more to the right you can see here in this picture...
... it is the third circuit under the socket. On the area where there is a stepped section there are several black spots in between the board and laminate. No other circuit has it. Rather strange looking, it doesn't appear to be normal corrosion, but I'm assuming this may be contributing to the Tachometer not working correctly.

Anyone with a Helms or electrical schematic able to tell which circuit that is?

*Didn't see the spots until I already had reassembled the cluster, D'oH!.*

MAD_MIKE

Digging around I found this...
I take it the wiring colors are similar for B1 and B2 engines?

Searched the internets and found this B&W photo of a '96 V6 EX tach test connector which looks exactly like the one on the '95

so I'm guessing the V6 wire colors would be different.

The million dollar question.
Do I need an adapter to connect the tach signal wire?
Or can I directly connect to the blue Tach Test connector and verify with an aftermarket tach, or my DVM's Tach 4cyl setting, what the signal wire output is?

TIA

ReaperMan

MAD_MIKE

Timing light, DVM hooked up and confirmed the Tach in the car is reading wrong. More than likely that circuit with the black spots is bad, along with my now never emptying fuel gauge.... bugger.