'89 CRX HF + D15Z1 troubleshooting...

[GasSavers_bobski]

Unplug your ECU, MAP, EGR and TPS sensors. Test the resistance between ground and each pin of the sensor connectors. Test the resistance between the pins at each connector. You should see no connection (off the scale resistance) in each case.

[MakDiesel]

Finally, Finally, found the problem! Seems Rywire instructions had me tap the wrong wire, thus causing the EGR to have fluctuating voltage and a crazy idle and rev decel. It now has 5 volts. What a simple fix it was. Anyway, with that out of the way, an 8 mile test drive ensued and I noticed a few other things:

- Throttle (as in gas pedal/TB plate) still sticks randomly, have to 'jab' the pedal to get it release
- Has a tendency to stutter/jerk/hop at low speeds in low gear
- Has a tendency to do the same at sustained speeds, barely noticeable, usually low RPMs again (below 3k).
- noticeable vibration through the shifter, might have to do w/ harder polyurethane mounts on engine and bushings in shifter being stiffer
- still can't tell if VTEC is engaging, I try to feel for it around 2-2.5k but I second guess myself
- slight gas smell after driving inside car, smell strongest behind driver's seat and next to gas door (only at 1/3 tank if you were wondering)
- NO CEL yay!

So I still have a few issues but my electrical gremlins have been vanquished! Thanks to all who helped out w/ that one....Mak

[GasSavers_bobski]

Originally Posted by MakDiesel

- Throttle (as in gas pedal/TB plate) still sticks randomly, have to 'jab' the pedal to get it release

That's not good. I would fiddle with the gas pedal while stopped, with the engine off and try to get it to stick. If it sticks, you can fiddle with the various components (throttle pulley, throttle cable, pedal assembly) to figure out which one is sticking.
My bet would be on the cable, then the pedal cluster.

Originally Posted by MakDiesel

- still can't tell if VTEC is engaging, I try to feel for it around 2-2.5k but I second guess myself

I think some VX ECUs had an output for an economy indicator light in the gauge cluster? Some, maybe all HFs had a similar upshift indicator... Hook 'em up.

Originally Posted by MakDiesel

- slight gas smell after driving inside car, smell strongest behind driver's seat and next to gas door (only at 1/3 tank if you were wondering)

The fuel filler pipe is back there. I would pull out the cargo box and maybe the driver's side panel to get a good look at the pipe. Someone may have driven a screw through the pipe to mount an amp or something in the past.
Another possibility is that the top of your gas tank has rusted through in a spot, and is letting vapors out. Maybe the vapors leak in through a torn gasket or something?

[MakDiesel]

Originally Posted by bobski

That's not good. I would fiddle with the gas pedal while stopped, with the engine off and try to get it to stick. If it sticks, you can fiddle with the various components (throttle pulley, throttle cable, pedal assembly) to figure out which one is sticking.
My bet would be on the cable, then the pedal cluster.


I think some VX ECUs had an output for an economy indicator light in the gauge cluster? Some, maybe all HFs had a similar upshift indicator... Hook 'em up.


The fuel filler pipe is back there. I would pull out the cargo box and maybe the driver's side panel to get a good look at the pipe. Someone may have driven a screw through the pipe to mount an amp or something in the past.
Another possibility is that the top of your gas tank has rusted through in a spot, and is letting vapors out. Maybe the vapors leak in through a torn gasket or something?

All good suggestions. I'll address each one, although I won't get to the car again til next week sometime.

1. I know when I rev the car at the throttle body itself w/ my hand it can still stick, so my guess is cable also, followed by butterfly plate/spring. Time for some WD-40.

2. I remember the Rywire instructions mentioning an upshift light connection w/ the supplied pigtail, I'll just have to track down the original HF one (if it has one, not sure off hand) or rig an LED somewhere.

3. As far as I know this car has little/no rust anywhere. I bought the car despite it's poor mechanical shape because of this quality. My guess is an old fitting/hose/gasket has met it's service limit or as you mentioned, an errant screw tip. I'll let you know when I've cured a few of these. Thanks again, Mak

[MakDiesel]

Back for an update....**edited for clarity**

- fixed the throttle stick, must be in the TB itself, I useda screw as a stopper on the throttle linkage/TB right before it sticks closed.

- the smell hasn't returned but I haven't driven it yet, just cranked/idled for 5 minutes or so.

- Hooked up "economy" aka shift light, VTEC engaged light, and clutch switch (dunno what for, my HF won't start w/o the clutch in anyway). So as I'm attempting to test drive and test all my new hookups, the car won't start She turns over fine but I couldn't hear the fuel pump so I did the jumper to main relay test and I have 12v at the connector to the pump/sender. I then hook up a 12v battery to the pump connector itself and I could definitely hear some pump action. I hook it all back up, and...nothing. Why would the pump work w/ direct 12v but not normally w/ a verified 12v coming to the connector? Mak


PS -- after making the pump run on straight battery, the car did crank/run for a few seconds til the gas went out of the line so air/spark are not of concern.

[mcamodell]

Originally Posted by MakDiesel

I remember the Rywire instructions mentioning an upshift light connection w/ the supplied pigtail, I'll just have to track down the original HF one (if it has one, not sure off hand) or rig an LED somewhere.

I would really like a V tech light in mine, what wire is safe to tap a LED into?

[GasSavers_bobski]

Originally Posted by mcamodell

I would really like a V tech light in mine

What... like this?

[mcamodell]

Originally Posted by bobski

What... like this?

Um, no