Starter-alternator cable replacement
06-16-2014, 08:58 PM
#16
Instructor
Thread Starter
Ok, I can only think of three more (less likely) possibilities:
1) When you measured 12.5v, are you sure you were touching the probe on the stud that comes out of the back of the alternator, and not on the nut or the wire terminal on it? Suppose the alternator generates 13.5v on the stud and there's corrosion between the stud and the nut/wire terminal, you could lose voltage there and falsely conclude the alternator is bad. This you can re-check.
1) When you measured 12.5v, are you sure you were touching the probe on the stud that comes out of the back of the alternator, and not on the nut or the wire terminal on it? Suppose the alternator generates 13.5v on the stud and there's corrosion between the stud and the nut/wire terminal, you could lose voltage there and falsely conclude the alternator is bad. This you can re-check.
2) Your belt is slipping somehow. Are the belt and the belt tensioner tight and in good condition? As the load of the alternator increases, the drag on it also increases so if your belt is slipping, the alternator won't be able spin fast enough to provide the adequate power. I don't know of a device that could test the rotational speed of the alternator (maybe make a mark on the alternator pulley and shine a stroboscope on it???). Speed of the alternator = engine rpm x crank pulley radius / alternator pulley radius.
BTW, belt was recently replaced at engine rebuild. BTW this all occurred after an engine rebuild. Was rebuilt by Flat6 due to IMS failure and collateral damage. Jake Raby personally test drove it for 150+ miles and had no issues at all. It was shipped back here to NorCal and had this problem immediately after coming off the truck. He has been very helpful but trying to diagnose this remotely is not easy.
3) There's a single wire that energizes the alternator with some small current controlled by the instrument cluster. So in theory it's possible that the instrument cluster circuit is bad. I don't even know how to test this and how complicated or simple this circuit is.
Personally I have not heard of 2 and 3 above but anything is possible I guess.
Personally I have not heard of 2 and 3 above but anything is possible I guess.
06-16-2014, 09:09 PM
#17
Yea, I cannot imagine how 1) can happen too unless the bolt is not tightened down, which is not likely. From what you described I think it's unlikely related to the engine work, regardless of who did it.
I agree it's difficult to find a theory that makes everything consistent. Really don't have much to go on other than replacing the alternator at this point.
I agree it's difficult to find a theory that makes everything consistent. Really don't have much to go on other than replacing the alternator at this point.
06-19-2014, 01:58 PM
#18
Instructor
Thread Starter
Well, it certainly looks like the first replacement alternator I got was in fact bad. The retailer ordered a new one (still Bosch reman) and got it overnight. I exchanged it (I'm getting really good at this) and the voltage responded much better. Immediately jumped to 14V on startup, and while driving never dropped below about 13.6, and in fact rose to 13.8 or so at the end of my 20-minute commute. No problems, no misfirings, no hesitation, strong all the way.
I'm pretty certain this was finally the solution. Will take a couple of days and some stop-and-go driving to be certain.
So anyway I replaced the regulator (not needed but not expensive, but a lot of work), the starter/alternator cable (appeared to help a little, and a common problem area so good to get that done), and the battery (was still strong but 6 years old).
I should also mention that the first alternator replacement was in a Bosch box as was the second. But the second one was in a sealed plastic bag, included a Bosch washer and nut pack, and had a sticker on it, none of which the first replacement had. It almost looked like the first replacement was a return that never got remanufactured. Buyer beware. I got both from Parts Heaven and they said they've sold 800 of these and had 27, now I guess 28, returns.
I'm pretty certain this was finally the solution. Will take a couple of days and some stop-and-go driving to be certain.
So anyway I replaced the regulator (not needed but not expensive, but a lot of work), the starter/alternator cable (appeared to help a little, and a common problem area so good to get that done), and the battery (was still strong but 6 years old).
I should also mention that the first alternator replacement was in a Bosch box as was the second. But the second one was in a sealed plastic bag, included a Bosch washer and nut pack, and had a sticker on it, none of which the first replacement had. It almost looked like the first replacement was a return that never got remanufactured. Buyer beware. I got both from Parts Heaven and they said they've sold 800 of these and had 27, now I guess 28, returns.
06-19-2014, 02:20 PM
#19
Another example of measurements don't lie 
Yes, it's not uncommon for those Bosch reman alternators to fail out of the box. Glad you seem to have it sorted out finally and nothing is wasted. The cable is prone to failure and the battery is 6yrs old and you definitely got your money worth already. The extra regulator could be used as a backup part.
Yes, it's not uncommon for those Bosch reman alternators to fail out of the box. Glad you seem to have it sorted out finally and nothing is wasted. The cable is prone to failure and the battery is 6yrs old and you definitely got your money worth already. The extra regulator could be used as a backup part.
06-28-2014, 08:02 PM
#20
i just did this this afternoon...thanks for the info mike.
that was a good tip on how to get the plenum back on...i struggled with that for a bit until i reread how you did it... as well as when i lost the connecting nut behind the alternator. but that was it. took about 2 hours and 2 honey brown lagers. only one trip to dads to get a bigger ratchet for the 24 mm socket.
fired right up. no cel which was a relief. just had to reset the windows and the head unit colour displays and its all good.
now on to the gfs brakes on her civic...
that was a good tip on how to get the plenum back on...i struggled with that for a bit until i reread how you did it... as well as when i lost the connecting nut behind the alternator. but that was it. took about 2 hours and 2 honey brown lagers. only one trip to dads to get a bigger ratchet for the 24 mm socket.
fired right up. no cel which was a relief. just had to reset the windows and the head unit colour displays and its all good.
now on to the gfs brakes on her civic...
Last edited by CDLVancouver; 06-28-2014 at 09:01 PM.
09-24-2014, 11:10 PM
#21
Instructor
Thread Starter
I am cross posting this to the couple of threads I started while chasing this issue. It appears to be FINALLY resolved. To recap, after receiving the car back from Flat6 after an IMSB-caused repair, the car violently misfired after some time. It was perfect when put on the truck at Flat6, and really bad right off the truck. It has taken 4 months to get to the bottom of it. I am indebted to Jake at Flat6 and Tony Callas of Callas Rennsport for providing a huge amount of initial help, and especially to Clint Pfeifer at Euro Trends in Ceres, CA who finally diagnosed and chased this down. In the end it had nothing to do with the rebuild, but may be a typical problem for cars with more than a few years on them, possibly especially from northern or other climates where corrosion can occur.
The bottom line was multiple layers of electrical issues: wiring harness and connector corrosion, slowly deteriorating electrical components, resulting in lack of spark when hot and intermittent CPS sensor. P0336 (CPS) fault code always thrown; P030x fault codes (misfires) thrown when severe misfiring occurred. Also learned: the ECU's fault codes are excellent starting points. If it throws a code, that is probably the problem, or very close to it. Don't start looking at other things until the entire diagnosis for the fault code has really been done, all the way down to the wires.
Specifics:
1. 3 key pins of the X59 connector pair in the engine compartment were corroded: two CPS sensor wires and the main V+ wire from the ignition relay supplying power to the hot sides of the coils and injectors. As the engine compartment heated up, the resistance of these connectors increased to the point where spark failed, causing violent misfires progressively getting worse as engine compartment temperature increased (usually while idling or after stopping for gas or an errand).
2. Numerous electrical components were slowly deteriorating and not supplying as much power as new parts: alternator, alternator/starter cable, corroded pins on X59 connector, engine/chassis ground strap. Ignition coils looked fine, but replacing them improved the issues. An additional ground strap was added from transmission to chassis.
3. The sum total of voltage issues eventually crossed a threshold where coils did not supply enough voltage to spark. The dominant problem was the V+ supply to the coils losing voltage at the X59 connector, but it was not the only one. As each component above was replaced, the issues improved but never completely went away until the last link in the chain was replaced.
4. CPS cable in engine harness is compromised somewhere along the line. Replacing the X59 connector pins for the CPS wires reduced the P0336 codes, but did not completely eliminate them. The final fix was to install a completely separate cable from CPS into the DME. This nailed the P0336 codes.
The car has about 150 miles on it since the final fix, under hot operating conditions, and has been running perfectly. Why the transportation from Flat6 to home tipped the scale, we don't know and probably never will. The problems were there all along.
The bottom line was multiple layers of electrical issues: wiring harness and connector corrosion, slowly deteriorating electrical components, resulting in lack of spark when hot and intermittent CPS sensor. P0336 (CPS) fault code always thrown; P030x fault codes (misfires) thrown when severe misfiring occurred. Also learned: the ECU's fault codes are excellent starting points. If it throws a code, that is probably the problem, or very close to it. Don't start looking at other things until the entire diagnosis for the fault code has really been done, all the way down to the wires.
Specifics:
1. 3 key pins of the X59 connector pair in the engine compartment were corroded: two CPS sensor wires and the main V+ wire from the ignition relay supplying power to the hot sides of the coils and injectors. As the engine compartment heated up, the resistance of these connectors increased to the point where spark failed, causing violent misfires progressively getting worse as engine compartment temperature increased (usually while idling or after stopping for gas or an errand).
2. Numerous electrical components were slowly deteriorating and not supplying as much power as new parts: alternator, alternator/starter cable, corroded pins on X59 connector, engine/chassis ground strap. Ignition coils looked fine, but replacing them improved the issues. An additional ground strap was added from transmission to chassis.
3. The sum total of voltage issues eventually crossed a threshold where coils did not supply enough voltage to spark. The dominant problem was the V+ supply to the coils losing voltage at the X59 connector, but it was not the only one. As each component above was replaced, the issues improved but never completely went away until the last link in the chain was replaced.
4. CPS cable in engine harness is compromised somewhere along the line. Replacing the X59 connector pins for the CPS wires reduced the P0336 codes, but did not completely eliminate them. The final fix was to install a completely separate cable from CPS into the DME. This nailed the P0336 codes.
The car has about 150 miles on it since the final fix, under hot operating conditions, and has been running perfectly. Why the transportation from Flat6 to home tipped the scale, we don't know and probably never will. The problems were there all along.
