RonK Posted June 3, 2012 Share Posted June 3, 2012 Just purchased a 1975 280z w 111k mi, driven 200-500mi a year past 10yrs. Drove it over 300-400mi w no problems. My mechanic(good friend of mine) checked it out for overall condition and determined alternator was putting out only 12amps (explains why battery is bad). I replaced alternator with a Bosch unit he provided me, started and ran engine for couple of minutes to make it was all good...no problems Replaced distributor cap, rotor & wires and now runs like crap (like timing is off or not firing on all cylinders). Checked and doubled checked wire order. Plugs are getting spark. Even tried putting old cap, rotor & wires back on but no difference. (btw, this is "transistor", not contact points ignition) Rotated distributor as far to each direction allowable but no better, just slower when retarded and faster when advanced but still running like My mechanic put the new plugs in to make sure that wasn't the problem but still running like crap and apparently continues to foul the plugs (hence, no lack of fuel). He tried working with the timing but no success. He checked the air gap on the one part (sorry, dont have manuel with me) located under the rotor. He's stumped at this point with limited amount of time he has been able to devote to it. Wondering if the additional amps (50 vs 12) fried something? (Is it pretty obvious how much of a mechanical rookie I am yet?) here I thought I would have something simple to work on, if need be...Crap, first simple thing I do, like change the alternator, cap, rotor and wires, and now it's screwed up and off the road! Signed, "Help The Rookie" P.S., my mechanic is now thinking the distributor may be bad??? Quote Link to comment Share on other sites More sharing options...
BluDestiny Posted June 4, 2012 Share Posted June 4, 2012 Possibly a vacuum leak. Maybe your mechanic had to move a line and it either cracked or he forgot to put it back on? Also what exactly do you mean runs like crap? bad idle, won't rev, will die under load etc? Quote Link to comment Share on other sites More sharing options...
RonK Posted June 4, 2012 Author Share Posted June 4, 2012 Possibly a vacuum leak. Maybe your mechanic had to move a line and it either cracked or he forgot to put it back on? Also what exactly do you mean runs like crap? bad idle, won't rev, will die under load etc? Apologize for the generality "Crap". It's running like not all cylinders are firing and it's getting plenty of fuel (my mechanic says it keeps fouling the plugs from so much fuel) Quote Link to comment Share on other sites More sharing options...
johnc Posted June 4, 2012 Share Posted June 4, 2012 Firing order is 1-5-3-6-2-4 and number 1 is between 7 and 8 o'clock on the cap. Wires are ordered counter-clockwise from there. That is the proper orientation. If your distributor is (was) not installed correctly the proper orientation may not work. Quote Link to comment Share on other sites More sharing options...
RonK Posted June 4, 2012 Author Share Posted June 4, 2012 Firing order is 1-5-3-6-2-4 and number 1 is between 7 and 8 o'clock on the cap. Wires are ordered counter-clockwise from there. That is the proper orientation. If your distributor is (was) not installed correctly the proper orientation may not work. Unfortunately, I wish it were that simple .. The order and wire placement has been checked and re-checked. Lol, my mechanic friend thought it was going to be that simple and was wondering how I could be that inept (I think the word he used was "stupid" ), however, now after checking the timing, installing new plugs, re-installed the old cap and rotor, he's scratching his head Quote Link to comment Share on other sites More sharing options...
Miles Posted June 5, 2012 Share Posted June 5, 2012 (edited) Check for a dead cylinder: You will need a pair of insulated pliers or a thick rag for this to avoid getting shocked. With the engine idling, pull off a plug wire and note if the engine rpm slows. If the rpm drops then the plug, wire, cap etc is working for that cylinder. If there is no change in rpm then that cylinder is not firing and you should suspect that the plug, wire, cap, rotor or distributor is at fault. You can swap in a spare wire, plug etc. to see if it cures the problem once you have identified the dead cylinder. If you don't find a dead cylinder then check every wire in the ignition system for corrosion and/or loose connection. Try swaping in a spare distibutor. I have had problems with new, but cheap, plug wires I purchased at the local parts store. Edited June 5, 2012 by Miles Quote Link to comment Share on other sites More sharing options...
NewZed Posted June 5, 2012 Share Posted June 5, 2012 (my mechanic says it keeps fouling the plugs from so much fuel) Maybe this clue means something. Is the water temperature sensor still connected correctly? The wires are in the vicinity of the distributor, maybe it got knocked loose. Everything might be fine except it's running super rich because the ECU thinks you're up in Canada in the winter time. Quote Link to comment Share on other sites More sharing options...
RonK Posted June 6, 2012 Author Share Posted June 6, 2012 Maybe this clue means something. Is the water temperature sensor still connected correctly? The wires are in the vicinity of the distributor, maybe it got knocked loose. Everything might be fine except it's running super rich because the ECU thinks you're up in Canada in the winter time. Question... if it thought it was cold wouldn't it just run faster but still run smooth? Quote Link to comment Share on other sites More sharing options...
RonK Posted June 6, 2012 Author Share Posted June 6, 2012 Update.... my mechanic thought maybe the distributor may be bad ... We swaped w reman'd distributor and made no difference. He is now wondering if the timing has jumped. Going to pull the over and check it out :-\ Quote Link to comment Share on other sites More sharing options...
NewZed Posted June 6, 2012 Share Posted June 6, 2012 Maybe this clue means something. Is the water temperature sensor still connected correctly? The wires are in the vicinity of the distributor, maybe it got knocked loose. Everything might be fine except it's running super rich because the ECU thinks you're up in Canada in the winter time. Quote Link to comment Share on other sites More sharing options...
RonK Posted June 6, 2012 Author Share Posted June 6, 2012 Asked my mechanic to double check ... Guess what? The water temp switch has a broken wire NewZed, you are Good!! Now, know where I can find one? Having difficult time finding one. Quote Link to comment Share on other sites More sharing options...
NewZed Posted June 6, 2012 Share Posted June 6, 2012 Asked my mechanic to double check ... Guess what? The water temp switch has a broken wire NewZed, you are Good!! Now, know where I can find one? Having difficult time finding one. RonK, I replied to your PM. As I said, he might looking at the vacuum advance switch, not the water temp sensor (WTS), since the WTS doesn't actually have wires, just pins. Easy to check at the ECU connector and worth doing. If the wires at the ECU don't give the right resistance for the temperature then you can look for problems between there and the sensor. Quote Link to comment Share on other sites More sharing options...
RonK Posted June 7, 2012 Author Share Posted June 7, 2012 RonK, I replied to your PM. As I said, he might looking at the vacuum advance switch, not the water temp sensor (WTS), since the WTS doesn't actually have wires, just pins. Easy to check at the ECU connector and worth doing. If the wires at the ECU don't give the right resistance for the temperature then you can look for problems between there and the sensor. Thank You, NewZed, for your reply. For the benefit of others, here's a copy of my response to your reply ... "The part with the broken wires is the water temperature switch (threaded into the side of the engine right below the distributor with two wires "molded" (for lack of better word) into it...one going to a bullet connection going most likely to the harness and the other is a "ground"?..it is secured by a bolt by the thermostat?? Any way, one wire was connected and the other was just hanging there. I must have damaged it when I was taking off the distributor cap. Unfortunately, MSA does not have it. They have one for a 1974, but it does not work (different specs as far as temps go). Apparently, 1975-1978 will work, but I am having no success finding one thus far. My mechanic is going to try and repair the existing one by drilling next to the broken wire (which is broken flush at the top of the "molded" material that connects the two wires to the switch) and solder the wire back in." Additionally, I will definitely check the other items, but the water temp switch is the most obvious problem (again, broken wire hanging there ). If you go to "The Z Store" (motorsports auto) and search "water temperature switch", one will come up for a 1974 260z. It is pretty much identical to my broken part, just it has its two wires coming out to a plug, where mine has one wire going to a bullet connection going most likely to the harness and the other is a "ground"?..it is secured by a bolt by the thermostat, right behind the distributor. Quote Link to comment Share on other sites More sharing options...
NewZed Posted June 7, 2012 Share Posted June 7, 2012 Some time with the Engine Fuel section of the FSM will save you and your mechanic a ton of time and money. Once the basics don't work, there's no better place to go next. An ohm-meter at the ECU connection with the FSM open will answer a lot of questions and probably lead to the source of the problem. You're at the head of the endless expensive path that many have followed. It's not a carbed small block chevy engine. It's easier than it seems, once you start testing things, it all makes sense. Quote Link to comment Share on other sites More sharing options...
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