rountreesj

my brother's civic is a 93 ex

d16z6. he put a new bottom end from an auto car with his old head in. wired all up and started the car last night. ran fine after a few seconds.

turned off, adjusted timing. started up again fine.

turned on one last tie for the night, and then it died.

now it will spin, but no spark.

checked dizzy from his car on mine, and works fine. mine is a 92 vx.

he has no codes on his p28 ecu.

he has power at the yellow/black wire at the dizzy.

fuel pump primes, the brake light stays on oil and engine light come on then go off.

any ideas?

Former User

Check the Yel/Grn wire for a short or open.

Battery voltage on the Blk/Yel wire?

rountreesj

he said he just checked voltage on the black/yellow and it gets 10.xx voltage, not 12.

he said the yellow and green wire gets continuity, but he did not check the voltage on it.

should he check voltage while he is trying to start it? or just with key to onII position?

rountreesj

he also put a known good ecu in the car and nothing as well.

we tested his distributer on my car and its fine

so distributer and ecu are fine.

no cel

cel goes on then off

gets fuel

timing is good

infamousavi

iTrader: (1)

There is a fuse inside the car by the SRS fuse, it's called ACG iirc. Check that it could be the issue

rountreesj

we just went and tested

black/yellow is 11.8 key on and 10.5 with car turnign over
yellow/green is 0.6 with key OFF and on, and 0.5 when turning over

i will go look at the fuse, acg but in the troubleshooting i didn't see it.

he said he already checked them all
but i will

Former User

rountreesj

if the yellow/green wire is getting constant power that would mean it doesn't have a hsort or open right?>

rountreesj

what voltage should be at the yellow/green

rountreesj

there is continuity at yellow/green

Former User

No. The Yel/Grn wire gets voltage from the ICM, not the ECU. And generally this wire has about 10V with the key in ON(II).

Do an end-to-end continuity test from the ICM to the ECU to test for an open.

Do a continuity to body ground test at the ICM side to test for a short.

Former User

What test? Describe what you did.

rountreesj

I did continuity test from the yellow wire with green stripe from the plug into the distributor back to the plug from the engine wiring harness into the other wiring harness which leads into the ecu/interior components. i confirmed that the wire going into the ecu was not the same color if i remember correctly. . i recall it was red witha green stripe (may be wrong) for the most part the wire seems "good". My running theory is that something is preventing the proper voltage to be supplied to give the signal to the ICM in order to trigger the ignition coil. THIS IS THE BROTHER of rountreesj. My question is what exactly could be causing loss of power to the ecu or elsewhere??? I borrowed a friends ECU because i was under the impression that mine MUST be bad. . .i was wrong. didn't do anything.

rountreesj

to clarify. . . i did continuity test with a voltmeter that beeps when there is coninuity through the wire. which IN MY OPINION isn't really hugely reliable however seems to be reliable on other things

rountreesj

are there grounds that i should check for around the ECU? i don't know where they would be exactly. or perhaps any common relays that control the ECU? I noticed an unusal symptom arose for the first time. while trying to start the car (turning it over with the starter) the check engine light would flicker very faintly. . . as if effected by the starter or starter switch of some sort??? something. question being is there some sort of wiring that could be lose up near the key ignition side or otherwise. It almost seemed like the use of the starter was sucking so much electricity that it was preventing the ECU from staying on. ???

rountreesj

I've run across alot of weird things going on before. . . bad horn made my break lights not work and interior lights turn on and off in my old crx. had bad parts in the distributor. I've never run across anything quite this frustrating. So all the help on this is appreciated. Thank you to all who are replying.

Former User

You only did a partial continuity test. Test continuity from the Red/Grn wires at ECU A21 and A22 to the igniter unit. Then test for a short.

Next do the igniter unit input voltage tests at the coil and igniter unit. See FAQs sticky for diagram.

rountreesj

I found a thick gray wire that has been run from a white wire next to a black and red wire. i think i may have found the issue. . . possibly the power wire TO the ECU? which wire is the power wire/wires to the ECU?

Former User

Where are these wires? Post pictures.

rountreesj

I did do a continuity test on the other wires that you mentioned. and did so basically each way about three times. partially completely each part connected every way possible. that ONE yellow and green ALL THE WAY to the ECU is good. HOWEVER as stated. . . there is a gray wire that has continuity that has been added ( looks to be in place of a lost wire) and then connected back to the same white wire (well if the white wire was there) where it is connected it has continuity yet at the end of the ECU plug the white wire no longer has continuity. is it safe to assume that this is most likely the culprit? or are there wires that aren't suppose to carry elctricity at any point to and from the ECU???

rountreesj

also this gray wire seems to have been run over and spliced in with a black wire witha red stripe.

Former User

rountreesj

correction gray wire is only attached to white BOTH ends. . BUT there is some sort of "jumper wire" going from white/gray wire splice crap thing to the black wire with red stripe

rountreesj

i will try to post pictures. . .but to your knowledge. . .is there any good reason for these wires to be in such a condition as described?? it seems like something someone did and just doesn't work well at all and should be put back to whatever is closest to correct.

rountreesj

i don't know how to upload pictures on here. my apologies