21 replies to this topic

[Hoosier Daddy]

ok, dropped rebuild in and tried to start. no go. got fuel, battery/alternator good, new cap/wires/rotor/plugs. no spark from the coil. new coil/ignition module. pulled a P0120 for throttle pos sensor. replaced it and cleared the code, still no spark. swapped cam sensor with known good one, nothing. rpm sensor is moderately new. what am i overlooking? could we formulate a comprehensive list of situations that cause ecu to pull spark? tried 2 ecu's as well, by the way. anyone in the columbus ohio area want to swing by?

[mdlimy]

put a meter on the coil just to see if it is getting any voltage, cam sensor and rpm sensor are the only things related so you are on the right path, only other thing it could be is the ECU or faulty wiring somewhere.

edit: retard here should have read the whole post, forget the ecu. check the plug that goes to the coil like i said.

[Hoosier Daddy]

ok, rpm sensor reads 330ohms so it's good. took the connector off the ignition module and tested the pins. all checked good. going to go back over wiring from battery tomorrow and see if there is anything there. cam and rpm sensors only things that give a no spark?

[CJones16]

My cam sensor timing was completely off when mine wouldn't start, The Part that goes on the camshaft wasn't right, I flipped it around and it started right up

Point I am getting to is maybe its something simple

Have you used a spark tester to confirm no spark?

Chris

[Hoosier Daddy]

old school screwdriver to struttower test. maybe my cams are f'ed up? seemed like the halfmoon only went on the cam one way

[CJones16]

Hoosier Daddy, on 05 October 2009 - 11:43 PM, said:

old school screwdriver to struttower test. maybe my cams are f'ed up? seemed like the halfmoon only went on the cam one way

The halfmoon can be rotated 180deg (Well mine would but maybe mines just messed up)


Inst the strut tower painted tho? I mean not good enough ground? You can also put the spark plug/wire on a bare metal surface in the engine bay to check spark (with the lights off in the garage its pretty cooool)

I think if the cams were f'ed then it would either run bad or you would bend a valve?

[Hoosier Daddy]

ok, gonna check the cam halfmoon thing and a plug wire.

[Hoosier Daddy]

ok, cam half moon is on correctly. rpm sensor tests good, maf sensor tests good. no codes in A1 or A2. had a code in A7 for missing rpm sensor so i cleared it and tried to start, nothing but the code did not come back. interestingly, i get no response when checking codes in A6 which is ignition center, yes? i'm getting really pissed now.

[Chilled Man]

hows your batterie ?

trust me I spent a whole day testing crap on a car to find out the batterie had died since I removed it from the car.

[mdlimy]

check all your timing marks and confirm that.

you are checking for sprak from the coil wire and not just a spark plug lead correct?

and you dont have the crank or cam sensor plugged into something else right? there is one plug that is around that area that i belive will interchange with either the cam sensor or crank sensor(cant remember)

[Hoosier Daddy]

spent a lot of today tracing continuity of wiring. after fiddling with the fuel relay and power to/through it, i found a place where a green wire branches out to the five injectors. moving and flexing that joint caused the readings to fluctuate greatly so i replaced it - to no avail. wouldn't a code be set if i had the cam or rpm sensor plugged in wrong? should there be a reading from the A6 circuit?

[mdlimy]

Hoosier Daddy, on 06 October 2009 - 10:37 PM, said:

spent a lot of today tracing continuity of wiring. after fiddling with the fuel relay and power to/through it, i found a place where a green wire branches out to the five injectors. moving and flexing that joint caused the readings to fluctuate greatly so i replaced it - to no avail. wouldn't a code be set if i had the cam or rpm sensor plugged in wrong? should there be a reading from the A6 circuit?

turn the ignition on and check the plug that goes to the cam sensor, you should have a ground, a 12v and a 5v, do you?

[Hoosier Daddy]

hmmm. 12v, 5v, 5v. fan relay is acting up, fan came on for no reason at all.

[mdlimy]

Hoosier Daddy, on 06 October 2009 - 11:41 PM, said:

hmmm. 12v, 5v, 5v. fan relay is acting up, fan came on for no reason at all.

weird, check the brown/black wire that goes into that plug and see if it is a good ground.

do you have an analog volt meter? (old school with a needle)

[Hoosier Daddy]

no, digital. i did check voltage at egr, which should have been 12v and it was at 5ish. used a scope to verify that it was not a pulsed voltage. i'll look at the ground on that connector

[mdlimy]

well shit if you have a scope just check the signal on the cam sensor!

should give you a signal like this

[Hoosier Daddy]

elusive ground fault somewhere. digging in tomorrow to look for it. fudge!

[mdlimy]

Hoosier Daddy, on 08 October 2009 - 06:26 AM, said:

elusive ground fault somewhere. digging in tomorrow to look for it. fudge!

let us know what you find!

[whitesnake]

Does the car crank over but not start? My sisters MX5 did the same thing when the head was rebuilt and it turned out that the fuel lines were mixed up. So swap them and see what the result is....

[Hoosier Daddy]

no, fuel is good. my wiring is poo poo. no ground to Cam sensor, no ground to MAF, no ground to damn near anything. jimmy rigging grounding in now, i'll post pics and see what happens