Still No Spark
01-19-08, 09:02 PM
#1
Still No Spark
1987 S4 N/A, with lower milage motor swap
Well, like I said in my previous thread we were going to swap out parts. Swapped out coils for known working coils, nothing. Swapped out ECU for known working ECU, nothing. Found that ECU wasnt bolted down on the top 2 brackets, fixed it. Nothing. Checked 80A fuse, its fine, put a bolt into it that wasnt in before, nothing.
ONLY thing I haven't checked is the CAS, but the thing is this car ran before with its old high milage motor... and the motor thats in it now ran fine in the donor car...I don't know how so much **** can go wrong when its being reinstalled! I checked the fuel pump before, replaced it now its got fuel.. (Btw fuel pump disconnected while I was checkin for spark so its not flooded)
Pulled off CAS cover and inspected it, it looks fine..but its operation is unknown.
Now, really is it possible for the CAS to be fucked? I have an s5 CAS that i could try out, but I really don't think thats the problem...I really need suggestions this is bs.
Well, like I said in my previous thread we were going to swap out parts. Swapped out coils for known working coils, nothing. Swapped out ECU for known working ECU, nothing. Found that ECU wasnt bolted down on the top 2 brackets, fixed it. Nothing. Checked 80A fuse, its fine, put a bolt into it that wasnt in before, nothing.
ONLY thing I haven't checked is the CAS, but the thing is this car ran before with its old high milage motor... and the motor thats in it now ran fine in the donor car...I don't know how so much **** can go wrong when its being reinstalled! I checked the fuel pump before, replaced it now its got fuel.. (Btw fuel pump disconnected while I was checkin for spark so its not flooded)
Pulled off CAS cover and inspected it, it looks fine..but its operation is unknown.
Now, really is it possible for the CAS to be fucked? I have an s5 CAS that i could try out, but I really don't think thats the problem...I really need suggestions this is bs.
01-19-08, 09:13 PM
#2
HAILERS
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You didn't say anything about whether or not you have 12vdc at the white, two socket plug at the Lead coil assy. The black/yellow should have 12vdc with key to ON.
Well, maybe you did.
So you just get out a CAS from another engine and put the electrical plug of the engine your woking on, on that spare CAS. Then key to ON, and spin the CAS's bottom gear. Look for spark. Got spark or not?
Is this the same type engine you had in the car? Same year? Same series? What harness did you use on the engine. Same one that was in the engine in the first place? Or?
Well, maybe you did.
So you just get out a CAS from another engine and put the electrical plug of the engine your woking on, on that spare CAS. Then key to ON, and spin the CAS's bottom gear. Look for spark. Got spark or not?
Is this the same type engine you had in the car? Same year? Same series? What harness did you use on the engine. Same one that was in the engine in the first place? Or?
Last edited by HAILERS; 01-19-08 at 09:21 PM.
01-19-08, 09:23 PM
#3
I do have voltage there. Somebody said that doesn't prove if you have spark or not, or some stupid crap iduno. I guess ill do it tomorrow, its too damn cold out...its like -15 celcius so what around 40-50 F.
How the hell do you take the CAS out? Seems like its just absolutely locked in there..
How the hell do you take the CAS out? Seems like its just absolutely locked in there..
01-20-08, 08:54 AM
#6
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The 12vdc on that black/yellow does not prove you have spark, what it does is PROVE that you have power to the coil assy and therefore KNOW the main fuse is working, which in turn supplys power to the ECU.
Knowing the fuel pump is working means you Know the engine fuse in the interior is good.
Taking your SPARE Cas and connecting it to the harness on the engine, and then spinning the bottom gear on that spare CAS with the key to ON, means you can now look at the sparkplug on the fender and see if there is spark or not. It takes but a few moments to do that.
The engine does not need to be turned over. Just rest the sparkplug wire on the fender near a strut tower stud, turn the key to ON, spin the bottom gear on your spare CAS held in your hand. Spark should occur.
I suggest that method instead of cranking the engine over for a reason. Sometimes the starter will pull the battery so far down there will be little to no spark from the plugs. The way described above eliminates the starter as a player so there's no voltage drop from it.
Like the man said, you do NOT need to remove the cas on the engine. Use your spare cas and connect it to the harness and spin its lower gear.
Knowing the fuel pump is working means you Know the engine fuse in the interior is good.
Taking your SPARE Cas and connecting it to the harness on the engine, and then spinning the bottom gear on that spare CAS with the key to ON, means you can now look at the sparkplug on the fender and see if there is spark or not. It takes but a few moments to do that.
The engine does not need to be turned over. Just rest the sparkplug wire on the fender near a strut tower stud, turn the key to ON, spin the bottom gear on your spare CAS held in your hand. Spark should occur.
I suggest that method instead of cranking the engine over for a reason. Sometimes the starter will pull the battery so far down there will be little to no spark from the plugs. The way described above eliminates the starter as a player so there's no voltage drop from it.
Like the man said, you do NOT need to remove the cas on the engine. Use your spare cas and connect it to the harness and spin its lower gear.
01-20-08, 08:59 AM
#7
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When you swapped out the engines you might have made an error. The ECU gets its internal grounds from a place on top of the rear rotor housing. It is a pair of black wires on a lug. The lug gets bolted to the top of the rear rotor housing. You cannot see this lug with the throttle body on the engine. Do not mistake it for that single wire that comes off the engine to the wiper motor area.
I"m saying that if that lug with two wires did not get bolted down, then the ECU cannot make spark or do much of anything of importance.
I"m saying that if that lug with two wires did not get bolted down, then the ECU cannot make spark or do much of anything of importance.
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01-20-08, 10:47 AM
#8
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I read one of your old threads. It seems you did right in ohming out the CAS wires etc. You rang the wires out from the ECU plug to the CAS? Say yes.
The thing should have started then, because you said you have 12vdc at the small, white, two socket plug for the Lead coil assy (black/yellow wire).
If you have power there, then the coil has power. All you need for spark is for the ECU to put a ground on THE OTHER WIRE in that two socket plug. It pulses a gnd. Don't go out and put one on that wire.
The CAS are pretty much bullet proof unless you stick a screwdriver inside one while its turning. Putting the elect plug on a spare cas and spinning its lower gear should produce spark if all the wiring is good and the ECU is good. What happens is the cas spins. It by itself produces a voltage and sends it to the ECU. IF the ECU is good it will send/pulse a gnd to the coil/ignitors assy and you'll have spark.
One thing in your last few threads causes mild alarm. If you grounded the coil assy thru the bullet connectors, it's Possible that could cause a ECU failure.
Hey, here's something very basic that should have been suggested earlier. IF you go out to the car and crank it over, do you see ANY movement of the tach needle? It won't be much, but it should at least twitch. Go do that if you can't get the cas out of the old engine. Write back.
Another thing. There is a solenoid resistor package on the EARLY 87 cars. So did the new engines harness have a plug for that item or not, and did the car come with one??? If you don't know what that is, look at the HAYNES or do a advanced search on this site for HAILERS for the name and Solenoid resistor as the item. You will get several hits and recently I posted a jpg of a solenoid resistor package.
The thing should have started then, because you said you have 12vdc at the small, white, two socket plug for the Lead coil assy (black/yellow wire).
If you have power there, then the coil has power. All you need for spark is for the ECU to put a ground on THE OTHER WIRE in that two socket plug. It pulses a gnd. Don't go out and put one on that wire.
The CAS are pretty much bullet proof unless you stick a screwdriver inside one while its turning. Putting the elect plug on a spare cas and spinning its lower gear should produce spark if all the wiring is good and the ECU is good. What happens is the cas spins. It by itself produces a voltage and sends it to the ECU. IF the ECU is good it will send/pulse a gnd to the coil/ignitors assy and you'll have spark.
One thing in your last few threads causes mild alarm. If you grounded the coil assy thru the bullet connectors, it's Possible that could cause a ECU failure.
Hey, here's something very basic that should have been suggested earlier. IF you go out to the car and crank it over, do you see ANY movement of the tach needle? It won't be much, but it should at least twitch. Go do that if you can't get the cas out of the old engine. Write back.
Another thing. There is a solenoid resistor package on the EARLY 87 cars. So did the new engines harness have a plug for that item or not, and did the car come with one??? If you don't know what that is, look at the HAYNES or do a advanced search on this site for HAILERS for the name and Solenoid resistor as the item. You will get several hits and recently I posted a jpg of a solenoid resistor package.
01-21-08, 10:03 PM
#9
Wow, okay thanks a lot im pretty sure you've covered every scenario thats keeping the car from starting...the thing is I got the car from a guy who bought it from some guys out west so i'm going by he said she said...for all I know they probably didn't reconnect those ECU grounds...I'll check everything out on sunday...I've gotta work all week and i've got a couple dates lined up...I'll get back to you guys on sunday.
02-17-08, 07:25 PM
#10
Okay, now, does anybody know which 2 pins on the connectors the ground wires are? Or am I gonna have to check every individual pin... and I was looking at my s5 motor and I heard that the ground attaches in a different spot and the only place I can see where a ground is, is the clip and wire is attached 2 the dynamic chamber. Now, rotary ressurection didnt say anything about these grounds in engine removal...but thats cause he removed the entire engine harness in removal..So what I think happened is the guys who had my car before who did the swap simply took the engine out without the engine harness and probably destroyed those 2 grounds...which is what im gonna check for when I ohm out the ECU pin connectors. Well, I'm gonna do an s5 intake swap anyway because I've got all the parts on my other motor...and its fairly easy compared to what i've done in the past..so yeah.
which I am going to start taking apart like right now...im taking off all the parts needed for the s5 intake swap and im gonna clean um and do it.
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