wjp005

iTrader: (3)

Hey guys,

I'm in need of some help. I can't get any spark so my freshly rebuilt engine won't fire up.

I have tested just about everything I can think of. Here's what I have checked and know for sure:

*Computer has all 3 12V power sources OK. (GY, B/W, L/R)
*Crank angle sensors are plugged in with the correct plugs (grey @ top)
*Ignitor has power on B/W wire
*Coils have +12V switched with ignition
*Coil packs has ground strap on them (8mm nut on top)
*Harness ground strap is connected underneath coils

I hooked my test light onto the other wires on the coils to see if I could see the ground signal "flickering" when cranking, but nothing was seen.

So studying the FSM wiring diagram (for a '94 even though mine is a JDM '92) I have narrowed down the problem to be either the ignitor or the crank angles sensor/s causing the lack of spark. Do you agree?

What I want to know from the gurus out there in the 'states is:

1) How do you test the crank angle sensors?
2) How do you test the ignitor?
3) Am I checking for spark correctly> I plug a plug into a lead and position it about 1/4in away from a known earth point, crank the car and watch for the spark to jump.

Keeping in mind that the car WAS RUNNING before I did the engine rebuild. I have checked all harness connectors I can find and nothing seems to be abnormal.

Does anyone have any other suggestions to try or answers to the above 3 questions? (I've searched these forums and couldn't find anything to help me)

A quick reply would be great guys, I'm anxious to get the thing running....

seandizzie

iTrader: (1)

I am no guru but you could check this. maybe trace the 8 foot run in and out of the car t see if somthing is amiss
Ignition Wiring Harness Improvement

Date: Wed, 19 Jan 2000 12:06:51 -0600
From: "Westbrook, Chuck E." (CWestbrook@tmh.tmc.edu)

The ECU on passenger side sends the firing trigger pulses to the igniter on the drivers side. This can't be changed and doesn't need changing.

The problem is with the wiring from the igniter to the coils. The coils are only about 2 feet from the igniter. But, the wiring goes from the igniter back inside the car to the main engine harness by the ECU, out the right firewall, to the engine where the solenoids are, across the front of the engine, then back on the left side of the engine to the coils. The 2 feet distance is now about 8 feet of wire carrying pulsating DC which can emit EMF if not properly shielded. This excess length also increases the possibility of the wiring being damage and/or misfiring.

While reinstalling my engine, I decided to go for the direct 2 foot route. The short ignition coil harness was removed from the main harness and the three coil connectors were cut off. These were then rewired with shielded wire to go directly to the igniter. The igniter output wires were cut and connected to the new harness. While doing this, the primary igniter wires were also connected to an extra male/female connector that allows them to run normally or be connected to my Crain HI6R.

Currently while breaking in the new engine, the Crane is disconnected and all are working fine. I did all of this to insure that the coils received the best possible signals and to increase reliability.

Do you know anyone around that would let you swap igniters to c if that is your problem??

________________

CantGoStraight

I'm not sure you'll see a spark if you don't ground the plug (need to complete the circuict) for it to spark. You can just stick a phillips screw driver in the end of the plug wire and hold it just off of a ground source to check for spark if you don't use a plug.

wjp005

iTrader: (3)

OK Thanks CantGoStraight.

seandizzie : do you know if this is true for my RHD car? Computer is on the left side footwell, and ignitor is on left hand side of engine bay.

I will trace the wire nonetheless.

Does anyone know how to test the ignitor & crank angle sensors? What sort of resistance, etc should I see??????

wjp005

iTrader: (3)

OK Guys, tonight I solved my no spark problem.

I traced and tested just about everything I could think of. Tested ignitor for power & earth : no problems. Tested the coils for power & resistance : no problem.

Last thing (of course) was the crank angle sensors. I had already given these the visual inspection (after having to pull off the powersteer pump + bracket & get the vacuum chamber out of the way.

Visually, they looked fine. They were plugged in to the right sensors, and the plugs felt firmly fitted to the sensors.

Now here’s the part where I finally won…. I unclipped the plugs to test for resistance through the wiring back to the car to check for open circuit or dead shorts. The first one checked out OK, my multimeter read 1992 ohms. Second one (white) read open circuit…………. Another careful inspection of the wires reavealed nothing unusual and then……….I wiggled & tugged on the wires and out came one of them!!! Seems the factory crimping job is pretty average. I must have dislodged the wire when unclipping the harness and tearing down the engine…….

So here’s some photos.

You can see from this picture that the wires appeared to be OK.


But have a looky here!!


I replaced the connectors with some utilux female spade connectors that were the correct width and slid on to the terminals nice and snugly. Hey presto, I had spark!! I then packed the sensors with silicone grease to keep moisture out and wrapped them in insulation tape.

I was then able to start my car for the first time tonight!!! Started right up, runs smooth as and sounds oh so sweet!!!

Just wanted to tell the story on the small chance it might help someone else out one day….

Now I’m off to install my coilovers, break in the engine and then have a play on the track in the next 2 weeks. I’ll let you guys know how I get on later…..

I’m off to enjoy my FD!!!!