Hym3n

'88 CRX DX w/ MPFI Conversion done by previous owner.

Distributor went out so I replaced it with another OBD0 Si (1.6L) distributor as directed by the MPFI conversion manual. Works great, car starts right up, I drive it around for a full day (~50 miles) without a hitch. The next day it drives just fine, but after ~5 miles throws a CEL, code 9, Cylinder Position Sensor, and the car starts running funny (obviously), bogging around and such. I lug it home and play with the wiring some, figuring something came loose since it worked fine all day the day before. Can't fix it.

Fast forward to yesterday I decide to take out the previous owner's wiring and use my own, thinking that perhaps the connector he used finally fell apart or something, who knows. It works! Car drives fine, enough to get me to a restaurant for lunch, but when I leave to start heading home, it gives me the same exact problem as above.

Today I ensure that the wire connections are good, and I can't make it out of my neighborhood without it throwing a code and bogging. It is still DRIVEABLE, but obviously not good for the motor and must be limped everywhere.

So my questions are as follows:

-Are certain distributors made for certain ECU's? I'm aware that there are several different ECU's that will accomplish the MPFI swap better than others, and I'm not sure which one I have, but perhaps there is a conflict between the two units.

-How can I test my existing Cylinder Position Sensor? I've been told that its a non-serviceable part inside of the distributor. Non-serviceable my ***, how do you fix/replace it? I'm not replacing the entire distributor again.

-How can I fix this???


Any input is appreciated!
Thanks,
Brian

Aesthetic Gains

iTrader: (1)

When you say " I replaced with another distribuitor" Was the dizzy new or used?
The ECU that you should be runnig for the stock engine is a PM6 if SOHC or JDM PR3/PW0 if DOHC. If I where you I would re-wire the entire MPFI set-up. Make sure you solder everything.

Janos Lin

It's non-serviceable in the sense that your average person cannot repair it properly.

There are vanes mounted on the distributor shaft, and magnetic pickup sensors mounted on the distributor housing such that they can pick up the changes in the magnetic field as the vanes rotate past the pickup. Two issues that make it non-serviceable is that you have to position the vane very precisely, if its off by a little bit it won't work properly. I'm not sure what the tolerance is on it, but I'd imagine plus or minus half a degree. If its off, then the engine wont run as well if that.

Also the magnetic pickup has to be mounted a specific distance with a certain amount of air gap, so it gets a clean reading. It's very close that u need specific feeler gauges to get it set right. Mechanics used to fiddle with magnetic pickup sensors when they first came out and only had nothing but problems and had to get a new one for it to run right.

HF and SI's have the same distributor essentially. DX is the odd one out.

It's probably a ground issue or interimment wiring issue. All it takes is one momentary disconnect for it to trigger the CEL.

Janos

Hym3n

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tonio &raquo;</TD></TR><TR><TD CLASS="quote">When you say " I replaced with another distribuitor" Was the dizzy new or used?
The ECU that you should be runnig for the stock engine is a PM6 if SOHC or JDM PR3/PW0 if DOHC. If I where you I would re-wire the entire MPFI set-up. Make sure you solder everything. </TD></TR></TABLE>
The dizzy was used. The guy assured me that it was still good, and I tend to believe him as the car ran without a hitch for a whole day. I will check and see what ECU I have, the reason I bring that up is because I wonder if maybe the original owner left the DX dizzy/ecu in there during the swap and just somehow rigged up the wiring (it all looks kinda hacked). Will check that out though.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Janos Lin &raquo;</TD></TR><TR><TD CLASS="quote">It's non-serviceable in the sense that your average person cannot repair it properly.

There are vanes mounted on the distributor shaft, and magnetic pickup sensors mounted on the distributor housing such that they can pick up the changes in the magnetic field as the vanes rotate past the pickup. Two issues that make it non-serviceable is that you have to position the vane very precisely, if its off by a little bit it won't work properly. I'm not sure what the tolerance is on it, but I'd imagine plus or minus half a degree. If its off, then the engine wont run as well if that.

Also the magnetic pickup has to be mounted a specific distance with a certain amount of air gap, so it gets a clean reading. It's very close that u need specific feeler gauges to get it set right. Mechanics used to fiddle with magnetic pickup sensors when they first came out and only had nothing but problems and had to get a new one for it to run right.

HF and SI's have the same distributor essentially. DX is the odd one out.

It's probably a ground issue or interimment wiring issue. All it takes is one momentary disconnect for it to trigger the CEL.

Janos p</TD></TR></TABLE>
THANK YOU for the input on that one, I definitely see how it is non-serviceable now. My next question to you, since you seem to know a lot about that sensor, is how can I test mine for proper operation? Additionally, it sounds as though if I swap my coil/ignitor onto another distributor "chassis" that has the CYP sensor still embedded within it, that I should be golden, given that mine is FUBAR. Sound about right?

I agree that it is probably electrical, I intend on going through and re-doing the MPFI conversion tomorrow afternoon in order to try and track this down. The problem is that when I got the car it was running great so I went through and soldered everything just to insure longer lasting, I don't understand how it would start acting up NOW when it didn't before. Like you said though, could be just an intermittent problem.

Janos Lin

yes you could toss in the coil and ingiter into the old one and hope that works.

Does the code come on immediately, or only when you start moving? If I recall correctly, any failure in the sensors would throw a code after a few revoultions because theres 3 sensors in there, the TDC sensor, Cylinder position sensor, and the crank angle sensor. If the system sees a discrepancy, it'll throw a code basically immediately at startup. The TDC one is what sets up the rest of the sensors tho. If that one is messed up, it wont know which one is #1 to go from there.

Oh btw, the service manual has the procedure for troubleshooting all of the components inside the sensor, including the CYP sensor.

Janos

Hym3n

Its different every time I start it honestly. Sometimes after idling (warm-up) for 30-60 seconds it'll cut on, other times I'll have to start driving and go 1/4mi-5mi before it turns on. I'm reluctant to say that it's the TDC sensor as that is a different CEL (code 8), and I was given that code upon initial startup when I had the wires crossed (they're both identical in color). Checking service manual tomorrow when I re-do the conversion, your help is much appreciated, thank you.

97_hatch

in for some answers.. jut bought my car and the ecu wires are all hacked up.. some wires werent taped or soldered so i just temporarily taped them.. started up my car then i got this same cel with it ruinning like ****. this is in my gsr though.


in for some answers..

Hym3n

Needed to get somewhere the other night and tried to drive it. It couldn't make it out of my neighborhood. Problem got worse and worse until the point where it just died and wouldn't start back up. Wound up pushing it a good four blocks back home. Thankfully this was in the middle of the night and there were no other cars around.

Resoldered every wire. No luck. Still won't start. I'm afraid I fragged the "new" distributor. Going to pick up another I suppose. My best guess is that this dizzy simply had an already bad CYP sensor.

monotech

iTrader: (2)

If you changed the distributer to a good working one then the wiring needs to be rewired or inspected very well. Could be a possibility C1 and C2 are reversed depending on how it has been wired up.

Hym3n

Well, I removed everything and tightened screws on the coil/ignitor, honestly didn't do anything else, and it started right up. I was able to drive it around some before turning it off, going to start it back up, and ultimately encountering the same issue again (CEL/sputtering). Limped it home and did the same, just tightened everything, and its been running great since.

With that said, its become pretty obvious that this is an intermittent wiring issue. I'm now stuck at my mom's house, can't keep it running. I have SOME tools on me, but here's the situation:

All wiring inspected and the swap was done properly. Every wire is in the correct position/attached to the correct wire.

My questions:
-My blue/grn & blue/ylw wires are soldered to a speaker wire, running to plugs that connect to the ECU. The wire changes gauge a couple times in this whole deal, but it is soldered at every position. Does the change in gauge matter?
-With the car running and a multimeter out, what should I be looking for coming from both the TDC/CYP wires? Should I measure for power or resistance or what?
-I'm aware that there are two wires, A16/A17 that are used as grounds for the TDC/CYP sensors. How does this work, and would bad grounds here cause my problem? Can I cut these wires and run them from the ECU to a chassis ground without a problem, or do they first have to run elsewhere?

Hym3n

Additionally, the car still starts and runs the same (CEL/sputtering until dying, obviously) when the C1/C2 wires are swapped on the distributor. Could running the car like this damage the sensors? Also, at one point one of the wires (not sure which) touched one of the battery posts and sparked--I assume that this would've killed the sensor, am I right?

Hym3n

bump

Janos Lin

Uh, from what I can recall, the distributor wires have shielding on them, I'm not sure where exactly as the wiring diagram in the service manual isnt helpful with that. If u've got speaker wires, chances are they're not shielded and may not work properly. The ECU is sensitive to EMI which happens in the distributor's high voltage system.

The shielding is, as I understand it, a second sheath of metal foil or such and typically is grounded, then a plastic cover over it to protect the foil. But it can also be just any other faraday cage style shielding.

Janos

Hym3n

Every wire I've played with/stripped so far seems very typical to me. Wire with the standard rubber(?) outer part/insulation that gets stripped away. In that sense, the speaker wire that I've got on there would be better than the existing wiring, as the rubber is quite thick.

I'll try some automotive grade wiring. Who knows.

Hym3n

And the **** just keeps happening.

Replaced the speaker wire with quality automotive wire, soldered and heatshrunk VERY well. Button it all up, and she runs! Feels like there's a little miss here and there, but I attribute that to the timing being off (I don't have a timing light and therefore aren't able to set the distributor properly).

So I drive it back home without a hitch in the world. Go in and chill for a little bit, then decide to go cruise and see if I can get it to act up again. I drive for 40-50 miles, no problems the whole way. Excellent.

Later in the night (this morning) around 2-3AM I again decide to go for a cruise now that the car has cooled down. Start it up, and immediately I notice the bogging, followed by a CEL within 8 seconds of start-up. WTF. Nothing happened except the car cooled down. My TDC/CYP wires are wired properly and soldered well. So what the hell. It runs then doesn't run. I don't understand.

Hym3n

Found a service manual for diagnosing code 9.

One of the first steps is to check for resistance between the blu/ylw & blu/grn wires. It should measure between 350-550ohms. Mine does not. If it doesn't, it says to replace distributor. That's all fine, but my question is:

There are two ground wires associated with the CYP/TDC sensors. Could bad/loose grounds cause lowered resistance?

teg_racer

just had the same prob, i have an 0bd1 gsr build the motor used same dizzy the car came with i have 1700 miles on it and randomly it sputtered and got this code. sputters at low rpm, my cap however has never been replaced and has 200k on it, maybe just needs a cap? or is this an internal prob

cdmef

bump for a reply on the resistance, I'm having the same problem, my cps reads 200, so could a bad ground cause this? and does a dizzy that reads 200 need to be replaced?

90_hatch_b16

yeah the resistance is supposed to be 350 - 700 ohms... so you need to find yourself another dizzy

Hym3n

Finally found another dizzy and replaced it. Car has run fine for a good 1,200 miles now, actually got 44mpg the other day too. A little sputtering problem that I've attributed to a shitty rotor will be replaced tomorrow.

THANK YOU EVERYONE FOR THE HELP... MUCH APPRECIATED.

-Brian