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90 CRX
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Discussion Starter #1
So for any of you who may have been following my previous post about my CKP sensor going bad (apparently) after replacing my head gasket....

I bought a BRAND NEW dizzy and the fucker is still throwing code 4.

And yes before i even bought this dizzy, i checked my wiring for continuity and yes there is continuity...

I've even de-pinned the harness plug and crimped down the connectors and hooked them up without the actual "plug" to ensure a good connection, still throwing the damn code.

I disconnected the battery and even un-hooked the ecu for like fifteen minutes thinking maybe the code didn't clear, but to no avail.

Please please please, anything that i may be missing TELL ME, i'm so frustrated with this thing right now after dropping that dime for the dizzy itself AND OVERNIGHTING IT!! :mad:

Any insight or advice is GREATLY appreciated.
 

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BATSLOMAN GIVES NO FUCKS.
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4,102 Posts
you sure its a code four? year of car? what engine? what ecu?
 

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90 CRX
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105 Posts
Discussion Starter #6
Are you sure the old codes cleared?
well after having both the battery and ecu disconnected for abotu 15 mins, i'm thinking they should've cleared

you sure its a code four? year of car? what engine? what ecu?
yes positive code 4, its a stock z6 in a 90 crx with virgin p28

check resistance of dizzy sensors at ECU plug.
This is will look into, but am i looking for it to be matching the resistance of the sensor itself or more or less checking for continuity to the ecu?
 

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94 Integra
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1,225 Posts
A continuity tester will not detect EMI, or electromagnetic interference. My first dpfi-mpfi conversion was plagued by it until I got proper shielded wire AND properly grounded the shield. When I had simply ran a totally separate wire between ecu & dizzy (with perfect continuity), it would randomly re-appear & go away.

If it was a converted DPFI or custom harness, there's a chance there is no shielding. If this is the original wiring, you will want to see if the drain wire (shielding) is grounded properly. There is usually one w/in the engine harness and another on the ecu harness. Those signal wires are covered by a grey sleeve a few inches inside the harness, and at one end they connect to a ground wire.

If you have a friend with a CRX, it may be easier to check if your distributors work on their engine & vice versa. Diagnosing and replacing wiring can be more time consuming.
 

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90 CRX
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105 Posts
Discussion Starter #9 (Edited)
Did you buy oem or aftermarket? Everyone says stay away from aftermarket distributors for hondas
its aftermarket, but i dont think it has anything to do with the dizzy's bc i'm getting the cel with both, one that was fine and began to throw code and a brand new (aftermarket) one

A continuity tester will not detect EMI, or electromagnetic interference. My first dpfi-mpfi conversion was plagued by it until I got proper shielded wire AND properly grounded the shield. When I had simply ran a totally separate wire between ecu & dizzy (with perfect continuity), it would randomly re-appear & go away.

If it was a converted DPFI or custom harness, there's a chance there is no shielding. If this is the original wiring, you will want to see if the drain wire (shielding) is grounded properly. There is usually one w/in the engine harness and another on the ecu harness. Those signal wires are covered by a grey sleeve a few inches inside the harness, and at one end they connect to a ground wire.

If you have a friend with a CRX, it may be easier to check if your distributors work on their engine & vice versa. Diagnosing and replacing wiring can be more time consuming.
right but i feel like that kind of problem wouldve arised sooner than this, no? i've had the car almost 5 years now and never had anything like this before?
and i think i know exactly what wire within the harness youre talking baout but i am also pretty sure that its my o2 sensor wire lol
 

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1992 Civic DX Hatch
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586 Posts
I am with hi profile on this. check for an open ground on the shielding wire. when you pulled the head did you leave a connector attached by accident? it is usually the coil and spark plugs that set off the EMI you may be able to shield them off with some tin foil to diagnose if that is the issue.
 

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Some times the ecu doesn't reset by disconnecting the battery or ecu. Try pulling the back up fuse for a few mins.

The new distributor could be bad right out the box. There all so could be a brake in the wire or short to ground causing the code. There's 3 wires in the shielding cable so not only can they short out to each other but all so the shield itself.
 

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90 CRX
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105 Posts
Discussion Starter #12
I am with hi profile on this. check for an open ground on the shielding wire. when you pulled the head did you leave a connector attached by accident? it is usually the coil and spark plugs that set off the EMI you may be able to shield them off with some tin foil to diagnose if that is the issue.
Some times the ecu doesn't reset by disconnecting the battery or ecu. Try pulling the back up fuse for a few mins.

The new distributor could be bad right out the box. There all so could be a brake in the wire or short to ground causing the code. There's 3 wires in the shielding cable so not only can they short out to each other but all so the shield itself.
ok so took off the entire engine harness last night and de-loomed the dizzy wires, went thru and all connections were good, no breaks in any wires. As far as the shielding it appeared that the wires for the CKP sensor were never shielded, along with the wires for the two-pin plug, and ICM.. the others were shielded so i do not think that was the problem.

HOWEVER I HAVE DEVELOPED A NEW SYMPTOM, not sure if its related but my speedo is now intermittently working. I first noticed this yesterday which prompted me to go ahead and pull the entire harness, but to no avail it sitll wasnt working this morning, except randomly on the highway it would work then go back out

So i feel like i've at least narrowed it down to either a bad wire in the ecu harness (firewall to ecu) or a bad ecu??
 

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I cant help with the code 4 but as far as your speedo there is a cable that come out of trans above the.diff.that goes to the back of the cluster. I would see if the cable backed out of the trans.
 

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I checked Identifix at work for a code 4 and everything points to the dizzy or ecu. I would triple check to make sure its a code 4 and not a 41.
 

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1992 Civic DX Hatch
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586 Posts
All 3 sensors wires coming from your distributor to your ECU should be shielded. The shielding should be grounded. The shielding should cover all the wire but the last inch or so before the connectors. Your issue is starting to sound more like a grounding problem. Check grounding locations G201 and G401. Those are the ones used in the speedo for a 92 civic may be a little different on yours.
 

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1992 Civic DX Hatch
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586 Posts
G101 is the sensor in the distributors ground location. It is the 2 wire one on the thermostat hsg.
 

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90 CRX
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Discussion Starter #17
I checked Identifix at work for a code 4 and everything points to the dizzy or ecu. I would triple check to make sure its a code 4 and not a 41.
THIS. this has been the MOST helpful post i've gotten. not to discredit the rest, i greatly appreciate everyone's help.

so yeaaa..... i was reading the code wrong, it was 41... and it turns out my o2 sensor just wasnt plugged in all the way :death::doh

so yes i win jackass award of the month, but thanks for the assistance DSO!!
 
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