'89 CRX HF + D15Z1 troubleshooting...

[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.

[GasSavers_bobski]

So you have 12V+ and a good ground connection at the connector under the cargo organizer box, but no pumping going on? That says to me that the gas tank wiring harness is screwed up.
What exactly do you mean by connecting power to the pump itself?
Try rigging something up so you can test the voltage to the fuel pump at the cargo bin connector while the connector is still hooked up. It's possible something is damaged in the car wiring or the main relay in such a way that it's creating high resistance. If there's no load on the damaged conductor (as is the case when the connector is unplugged), you wouldn't see a voltage drop, but at the same time the resistance wouldn't allow enough current to pass to run the fuel pump.

[MakDiesel]

To clarify I hooked up a 12v lawn mower battery to the cargo connector and something definitely kicked on in the tank, come to think of it, all those times I test-ran the car or test drove it the pump wasn't loud at all, had to have an assistant to listen in the refiller pipe. The fuel pump in my '85 CRX Si is LOUD. I hear it kick on and prime, and also while running. I even hear the whirr noise fluctuate when I have a blinker on (especially while idling at a stop light, etc). The HF, not so much. I'll try testing it w/ everything hooked up like I did the TPS. Thanks Bobski, you are my best suggester Mak

[MakDiesel]

ok, so here goes:

1. I got the car to run, but my fuel pump kill switch seems to be too good at it's job. I fully tested the main relay, another spare relay, both fine. I jumped the fuel pump to run w/ ignition on, no problem, can hear it fine. It seems when I manipulate the kill switch (which is upstream of the main relay) it sometimes interferes with the signal to the fuel pump relay and has to be "reset", usually by turning off the kill switch (no power to pump), removing the key in the ignition completely, then turning the kill switch to the "ON" position (and thus power to pump), then reinserting the key and starting the car. This convoluted method works 90% of the time. The other 10% I disconnect the negative battery cable for a few seconds then repeat the above process with mostly success. If/when I get the car to fire (and the pump is audibly primed beforehand) the car never cuts off unless I remove the key like normal or cue the kill switch. The kill switch is a simple lighted rocker and I've decided to upgrade to a true relay activated, um, relay switch. This should clear up my starting issues. Same goes for the push button start, although I've never had a problem yet from it.

2. The throttle still sticks shut, I've determined its not the throttle plate or the spring/cable, it must be the shaft that it rotates w/ or even a sticky TPS. Oh well, I adapted a machine screw to stop the cable/spring from hitting rock bottom and it has worked so far, although it seems to slowly back out.

3. I also blew several LEDs up testing my VTEC engagement light, all the LEDs tested were spares w/o voltage readings and apparently none could handle 12v. My MM confirmed that w/ the front wheels off the ground, w/ the car in 1st or 2nd, and the temp. gauge a little off "C", my VTEC engages at 3.5k RPM. I suspect on the road the engagement will be at the lower 2.5k but w/o load my test set the bar higher and MAP vacuum wasn't strong enough at 2.5k.

4. Shift light works! Also noticed on the VTEC tests the light kicks on once at a low, slow, RPM shift point and again briefly up past 3k. Odd. Also cut the clutch switch that I just hooked up b/c the HF already had a functioning one somehow. No CEL, oh well.

Once I re-wire and relay the kill switches I may be able to take the beast out for an alignment and that much closer to a DD. With all my electrical issues lately I will also invest in a mini-fire extinguisher. I don't need 2.5 years of tediously slow progress going up in flames b/c of some errant ground or short. AD

PS. Sorry this has become a build thread of late. Comments welcome, however.

[101mpg]

Oh, don't be sorry this has become a build thread! It's got at current 789 views and counting! Popular threads are popular threads, and it happens to be one of my favorites, too. Keep us all posted. I'm very interested as I would like to eventually put a more powerful and efficient engine in my CRX too.

[MakDiesel]

It's long overdue update time...

The Project FrakenRex (Think Kraken) is road legal, aligned, and one solid color! She has been driven approx. 120 miles over the past few months, usually one day a week for city/errands b/c there are still some engine issues to deal with that are keeping her from DD duty. The number one issue is an odd occurrence of what I call ICB, or Irritating Cruise Buck (not intercontinental Ballistic Missle). Under throttle, hitting VTEC, light cruise, etc she is pretty smooth, but say I achieve 30, 55, 0r even 70 mph and then let off the throttle completely and coast in gear to a stop light/down hill, etc. Only during this no throttle coast (in gear) does the car irritatingly jerk, buck, surge and fall, etc (the severity is very high in 1st gear, and lessens as the gears increase, but in 5th @ 70 it's still very noticeable). To the driver behind me it probably looks as if I am getting a first lesson on driving stick. Any suggestions? See the first post for a mechanical backstory. I'll post new pics eventually. Thanks, Mak

[GasSavers_bobski]

The engine shouldn't be able to do anything to cause bucking during a no-throttle coast - the fuel injectors shouldn't be firing. Make sure the throttle cable isn't too tight (and holding the throttle open slightly), then check the TPS voltage when the throttle is fully closed... It should be between 0.45 and 0.5 volts.

[MakDiesel]

I tested the TPS, .42 closed, 4.5-4.8 open. The throttle plate continued to stick closed so I took the TB off and gave it a good cleaning. The plate STILL sticks and I've resorted to sanding the high spots w/ 2000 grit sandpaper. I could really use a spare TB to help rule out this possible cause, either the sticking or iffy TPS. Also, there were not any voltage spikes when continually opening/closing the plate. What else? IACV? ECU?