another no spark problem
 

i have volts at lead coil and the green test plug, the dummy lights come on also. fuses are good. cleaned the mounting points for the coils and still no spark. so ive determined that the coils them selves or the cas is bad. would rather be the cas but i dont know how to check the cas with out another cas......been searching but i will keep doing so. in the mean time can anyone tell me how to check the cas with out another cas to use?

You can remove the CAS and spin its wheel w/key to on and you should hear clicks coming from the primary injectors and plugs firing if things were working properly, thus if you hear at least some clicks then the CAS "should" be good. You can also disconnect the CAS plug and clean it to see if this helps any. And when was the last time the leading coil worked?. Did it just stop operating recently? Lastly, what wire at the Green check connector had voltage w/key to on? Was it the Black/White wire?

i just bought the car for 400 bucks. i dont know the last time it was even running but it looks like a while. the coils are fine i tested them in my other car and they work. i did clean the cas plug and still no spark. the tach does not bounce at all even just the first one when you turn the key to on. i checked the cas plug with an ohm meter and it reads dead. would that be the emc not sending a signal to the cas? ill take the cas out and spin it with key on to see if it sparks with key on.

no spark when i spun the cas with it out, still hooked up and key to on......cas bad?

thank you for such a fast reply

Did the injectors make a clicking sound? And what wire at the Green check connector by the leading coil has voltage w/key to on?

You can also add to your post some additional information within 20 minutes of making that post so as to cut down on all the individual posts.

oh lol i didnt know that. i dont use the club much. it was the b/w wire that i tested, no the injectors did not click but they do when i jump the test plug

What test plug are you talking about? W/key to on how about measuring the voltage on the Brown TPS wire w/it plugged in. Should read about 5 volts. If so then this proves the ECU is being powered up which would eliminate one of the possible causes. Also, measure for voltage w/key to on at the TPS on the Black wire which is a ground so it should have zero to very little voltage.

The tach signal comes from the trailing coil pack, if you have no spark you'll have no tach signal.

the yellow 2 wire plug at the passenger strut tower. ill check the tps wires. tps on s4 is right under the bacv correct? if it is with key to on both brown and white and black and white wires read same at battery...12v

The TPS is at the front of the throttle body and has three wires to it. The two I mentioned plus a Green/Red wire. The two wire Yellow plug at the strut tower is the Fuel check connector used to check the functionality of the fuel pump and should not induce the injectors to fire/click.

duh lol makes sense. this thing is a nightmare. thank you for you help everyone. i have a friend that is coming over later today with a good ecu and cas. also it is a n327 with hi imp injectors... it has a resistor box by pass headlight but no sign of a plug for it..... dont they need a resistor box hooked up?

yeah im not getting anything from the tps at all. so that means the ecu is bad correct?

going to go get the ecu and cas from my friend.

What about the Black ground wire at the TPS as it should have zero volts. You might very well have a loose connection in the wiring that leads to the ECU. There are two Orange connectors located to the top and right of the ECU and these connectors mate the Front harness to the Emission harness. The ECU has three plugs. Focus on the smallest plug, top row, far left position, which should be a Black/White wire. This wire needs to have 12 volts w/key to on and this wire powers the ECU. W/o this wire doing its job the ECU does nothing.

The box is for low impedance injectors so it would be bypassed if the injector impedance was changed.

oh ok thank you. makes sense that it doesnt have a plug then. ill test those wires for the ecu right now. i have a good spare ecu and two cas now also so i can test those with it as well.

all three wires do not show any volts at all.

new ecu gives spark to the leading but not trailing. still wont fire up. any thoughts?

The car only needs the leading coil to start and run so it's possible that the engine is flooded or you have a different type of fuel issue. If you remove the return fuel line and place it in a jug, and w/the Yellow fuel check connector jumpered, and key to on the jug ought to fill up w/fuel. If it does then deflood the engine. One of the better deflood methods is to unplug the fuel pump and shoot at most two seconds of starter fluid into the air intake and try to start the car. The car should start briefly and then die out. Do this process two or three times and then reconnect the fuel pump and try to start it in a normal fashion.

thanks, still trying to figure out why i dont have spark from the trailing when it has power going to it and its grounded...dont care about not having spark but i want the tach to work. i put about quarter of a can of amsoil in each rotor housing to free up any gunkyness. the car was sitting for a year and a half before i got it. i got it started for a few minutes earlier but it was smoking off the amsoil and bad gas im assuming cause it was smoking like usual when you do that treatment but now it wont start back up. tried de flooding by pulling the fuses out and plugs and just cranking it. still nothing. it wants to but no quite there yet.

Is this an S4?

There is a Black wire coming out of both coils which connects to nothing. Jumper these two wires and the tach will run off of the leading coil.

yeah it is, thanks for the info. ill give her a try tomorrow morning with new fuel and a fuel filter. plugs are in good shape.

so im only getting spark to the leading coil pack, that should start the car however only l2 is firing. ive torn the pack down to nothing and redid all the connections and got all the corrosion off. they look brand new. another thing i replaced the n326 ecu with a n327. ive heard if the first three are the same they will work with out modification.

Both L1 and L2 should fire at the same time so if one fires then so should the other. Perhaps the coil is ill. Switch the plug wires and see if the very same thing occurs.

have you changed plugs after throwing amsoil down the engine?.
I had a car that would foul plugs if you premixed it a little too much,It would run like crap on the trailings.

if i take l2 wire off but leave l1 on there is only a faint noise of probably l1 sparking. if i take l1 wire off and leave l2 wire on there is a substantial spark.....they are older plugs but im not testing at the plug. ill go get new plugs and test at the plug. earlier when i did test at the plugs they were not sparking hard at all. the plug wires are brand new.