|
|
|
|
|
|
|
#1
09-05-2004, 09:02 PM
|
|||
|
|||
|
1993 300e 3.2 liter coil #2 not firing
I have just changed the wiring harness on my 300e, it was shot. New one went in easily. THe car is still running rough. Changed plugs, which uncovered the harness problem. Now I have switched coils and wires around and it seems that the cylinders for the second coil are not firing. DOes anyone know how to check the input side of the coils? I tried moving coils and the problem stayed indicating that the coils and wires are fine. Someone mentioned boots in a post, I moved them around also and the problem still remains on the same two cylinders. Any help would be appreciated.
|
|
#2
09-05-2004, 10:05 PM
|
|||
|
|||
|
Because the second coil [ T/2]is cyl 4 and also fires in series with cyl 3 ,
[ being adjacent cylinders], ..you may want to do a quick compression check for possible head gasket blow out between those two cylinders first........... Last edited by Arthur Dalton; 09-05-2004 at 10:39 PM.
|
|
#3
09-06-2004, 06:34 AM
|
|||
|
|||
|
THanks for the Information, but I messed up some info. Its the first coil that is not firing which is for cyl 2 and 5 I guess. Until I saw your answer I didn't make the connection that I was thinking "the coil" sitting atop cyl 2.
|
|
#4
09-06-2004, 09:54 AM
|
|||
|
|||
|
Quote:
Cancel my possible head gasket theory..Not adjacent cylinders with correct info.....[ T/1 instead of T/2] See next post.
|
|
#5
09-06-2004, 06:38 AM
|
|||
|
|||
|
Quote:
jsb
|
|
#6
09-06-2004, 09:52 AM
|
|||
|
|||
|
First thing to do [you may have gotten this far] is to change both plugs and the connector under the coil...plus check the wire to 5 for continuity.
The spark from the coil completes a loop for two cylinders in series. Goes from the coil- connector- plug- block- plug- plug wire- coil. Any break here in this chain and you get no spark.[ most common is plug connector under coils]. Common practise to change them w/plug change, regardless.... If you want to check for B+ , it will be at the coil primary input. It is constant 12V . , as the coils are a switched ground at the ECU [ switching transistors] Last edited by Arthur Dalton; 09-06-2004 at 09:58 AM.
|
|
#7
09-06-2004, 11:33 AM
|
|||
|
|||
|
THanks for the info. I did do those things. I also checked the input side of the coil, which all 3 coils show as a constant 12v. I took the plug wire off a good firing cylinder (1) and checked it for spark (good) then did the same for 5 using the same good wire (no spark). i will change the boots on all the coils even though i think I have proven them OK by substituting one for another.
A question. Since I was having a sporadic missing problem and decided to change the plugs, it was due, then uncovered the bad harness issue, IS it possible that --- 1. THe harness could have damaged something. 2. The system is smart enough to shut down the cylinders associated with the number one coil, assuming that it was the one missing at the start and need to do something to allow it to work again. Also in my testing of the old harness, after removing it I traced the structure of the wires to each coil and they seem to be made up off 2 wires into each coil, 1 is a common which comes from a wire terminal block on the left wheel well, Is this the ground? and the other is a seperate wire for each coil originating in the large multiwire terminal connector. I assume this is the pulse side for firing order.
|
|
#8
09-06-2004, 11:42 AM
|
|||
|
|||
|
From the info you have givin, it is possible to now have a bad switching trans in the ECU for that coil. That is what completes the ground circuit ...it may be open from the bad harness shorting...
Scope testing...ecu replacement may be needed. Did you/can you get the codes from pin#8 on diagnostic socket [HFM/SFI , ign/fi module] ???????????? Last edited by Arthur Dalton; 09-06-2004 at 12:22 PM.
|
 |
| Bookmarks |
|
|
Hybrid Mode
