EA82 Misfire and Tach jumping

[86 Wonder Wedge]

Alright ladies and gents, this one has my head scratching.

 

91 SPFI EA82 5MT

 

At cruise, random lurching/bucking/misfiring and tach is jumping several hundred RPM while trying to maintain speed. At WOT, purrs like a kitten and pulls hard. Upon engine braking, the tach jumps several THOUSAND RPM but the engine is smooth. Tach jumps all over the map on engine braking. Will also do this in idle. And when it lurches, it's very sharp and sudden, like a hiccup.

 

Cap and rotor have less than 20K miles, as do NGK wires and plugs, original coil which tests within resistance specs on both the primary and secondary windings.

 

CAS is original, rotor is NOT loose on the shaft, however, I can rotate it about 10-15* with some resistance. NO shaft play.

 

Wires are seated fully, good connections at all the CAS, transistor and coil plugs. Good, clean ground.

 

No check engine lights, but haven't looked for stored codes yet.

 

Now for the kicker: Car does this intermittently. Sometimes it will, sometimes it won't. Seems to disappear every time I screw with the coil-to-cap wire at the coil.

 

Ideas?

 

I've got an extra transistor and CAS, and I'm at wit's end on this one... If someone has a SSM they'd like to lend, I'll gladly compensate...

Edited February 1, 2014 by 86 Wonder Wedge

[rdweninger]

Same symptoms I had on my '85 EA82 and my '83 EA81.    I rebuilt my distributor in both cases and that fixed the problem.   I did NOT rebuild the disty myself.   I had Philbin Electric do it.   Cost about $140.  They do excellent work.

If you have a spare disty... try it.   Not sure what they cost new or if they are available or the quality.  

Hope this helps.

[86 Wonder Wedge]

Well, got home and looked around under the hood since it was driving fine.. But after revving it for a min in the garage, I got it to act up and we've got purple lightning! Arcing from the coil positive to the HT post and from the negative to the HT post. Make sense cause the needle would bounce higher (mostly) versus lower indicating extra discharges.

 

Now I'm not sure if this means a bad coil or bad HT wire.. My guess is HT wire since every time I play with it, it seems to "fix" the problem.. That boot on the end does seem to sit a bit high...

 

Will report back!

[86 Wonder Wedge]

Update: Well, I think I've fixed it? I also had the symptom of the alternator charging at less than 12V (11.5V approx) until I hit 4K RPM, then it would charge normally, then return back to low voltage. Also, no fuel pump cycle in D-check mode, but EGR and canister purge would cycle.

 

Well, after multiple days of terrible driving, and running the tests by the FSM, swapping the CAS (distro has ZERO play) and coil and transistor with known good ones, checking the TPS, checking the wiring, running the D-Check mode (good lord, what a process) then finally resulting to checking the timing belt for looseness, I believe resetting the ECU has fixed my problem. I had the battery unhooked for about 30 mins screwing with the belts and cover, I reconnected to watch it and it didn't act up one bit. It's been approx 200 mi since I've reset it with no indication of the problem. I've got full power, idles like normal, alternator is charging normally and no more jumping tach.

 

What has me skeptical is that the battery is a new Optima red top (for the sealed factor, I didn't want my frame/battery tray eaten alive) and the terminals are BEAUTIFUL. Didn't touch the fusible links or any of the fuses as well. Even screwing with the wiring when the battery was connected did NOT have a different result. The only change was "resetting" the ECU.

 

 

TL;DR I believe a reset (no power for 10+ mins) of the ECU has fixed my problems. Erratic alternator charging, misfiring (multiple discharges, not failure to discharge), jumping tach, and puel pump cycle again in D-check mode. Have 200+ miles with no problems.

 

P.S. If you're going to run the D-check mode, you MUST drive the car. Failure to do so will pop-up false codes. I ran D-Check in the garage and pulled codes 35 (purge solenoid), 51 (Neutral switch) and 33 (VSS), but none of those came up while driving in D-check mode. So just a heads-up.

[86 Wonder Wedge]

Update 2: Problem's back but fixed it again.

 

Thought I had it licked, but the problem has appeared again, but to a lesser degree. Now only happened below 3K RPM.

 

voltage was starting to become erratic, under 12V under 3K RPM and over 12V above 3500 RPM. However, the car would behave normally when voltage was under 12V.

 

Took it home, hooked up the multimeters, one for VAC and VDC. Ran the car and sure as hell, as soon as the VDC picked up, the VAC spiked to 2VAC! VDC dropped and VAC was under .05 .

 

Long and short, the 3rd Maxima alternator was pumping out VAC and screwing up my ECU. Swapped on the original, 130K mile alternator and have had zero problems. So far, ~100 mi on this setup with no problems. Car runs smoother, no more weird harmonics and the gas mileage seems to be up from the past few weeks.

 

TL;DR Another reman'd Maxima alternator was spiking VAC into the system causing erratic behavior. Original alternator swapped back on, zero problems so far.

[TheWanderer]

Certainly sounds like a bad voltage regulator in the alternator... If this is the 3rd Maxima alternator, perhaps its a cue to get a better alt A1 Cardone makes fantastic remans (made in USA, right around Philadelphia iirc).  Give it a shot, seems that since you changed to the original one that the problem is fixed, pointing me to believe it is a faulty alternator.  However the arcing along that wire makes me wondering if its a combination of issues, one being that wire is toast...

[86 Wonder Wedge]

Certainly sounds like a bad voltage regulator in the alternator... If this is the 3rd Maxima alternator, perhaps its a cue to get a better alt A1 Cardone makes fantastic remans (made in USA, right around Philadelphia iirc). 

 

I'm going to have to disagree with you there... Primarily because A1C does not reman alternators and secondarily, because even this Hitachi-reman (the OES) failed. I don't use cheap parts on my cars. However, I will say the pulley alignment was off 2.5 degrees due to the pulley swap, creating the potential for bearing failure, there was zero shaft play. I'll let it remain a mystery as to why the rectifier has failed on this one and the VR failed on the other two.

 

Also, while A1C doesn't particularly put out a BAD product, but having a LARGE inventory of A1C remans in my store, conservatively less than 20% of them are reman'd in the USA. The only item I can vouch for being made in the USA is their new master cylinders. Their brake calipers however are not impressing anyone around here.

Edited February 19, 2014 by 86 Wonder Wedge

[TheWanderer]

I'm going to have to disagree with you there... Primarily because A1C does not reman alternators and secondarily, because even this Hitachi-reman (the OES) failed. I don't use cheap parts on my cars. However, I will say the pulley alignment was off 2.5 degrees due to the pulley swap, creating the potential for bearing failure, there was zero shaft play. I'll let it remain a mystery as to why the rectifier has failed on this one and the VR failed on the other two.

 

Also, while A1C doesn't particularly put out a BAD product, but having a LARGE inventory of A1C remans in my store, conservatively less than 20% of them are reman'd in the USA. The only item I can vouch for being made in the USA is their new master cylinders. Their brake calipers however are not impressing anyone around here.

 

YMMV of course.  I've never had an issue with reman Cardone products (in particular their alternators, water pumps, and the aforementioned brake calipers), and all of the ones I've purchased have been stamped Made in USA.  Granted, give the choice I'd rather purchase new from the Cardone Select line but there isn't nearly as much available IME as there is for their remans.  Then again, i also don't buy off the shelf from the chain stores much, usually resorting to Rockauto, and if I do buy off the shelf I go directly to wholesalers for white box stuff (API in particular). I also tend to support Cardone because they were a local company to me before I moved west. and I prefer to support local companies first and foremost

 

 

Not unlike you, I don't use cheap parts on my vehicles either.  I wouldn't consider Cardone to be cheap, their quality is quite good IMHO.  Paired with the lifetime warranty vs the 12 mo/12k mile of most of the other parts manufacturers, my bid goes to Cardone.  My second choice being Bosch units if I can't find a Cardone for my specific purposes.

 

As for their brake calipers, unless their quality has gone downhill within the past 4-5 years since I last had to replace calipers, they were and remain to be some of the better semi loaded ones I've used...sure, the pads that come with them suck, but what do you expect from an off the shelf $5 set of semi metallic pads that come free with a $60 caliper?  Nothing ya can't fix by getting better pads, they are cheap enough anymore...

Edited February 20, 2014 by TheWanderer