jwgarvey

nice job akorna

sent u and email adrian. check your box

tested test coil today with breaker point dizzy, no change ugh! completed compression check. 1 145, 2 140, 3 145, 4 145, 5 145, 6 145. all looks acceptable. tested test dizzy from a 1978 280z with gm hei. results in. no erratic bounce in timing at idle (great) when checked with timing light. cars runs better (I had to take it for a spin). all spark plug wires are firing at idle (verified with timing light) accept cylinder one. getting late atm so I will have to save the rest for latter but it looks good so far. have to replace the cap and rotor as they are very very old. mechanical advance working correctly. have to work out the kinks over the next couple of days so I dont want to say this one is solved just yet but it looks promising atm.

fsm states 164-178 best regards John

gm hei contol module will be used with test dizzy, stay tuned.

picked up test coil, 1978 test dizzy, and compression tester. 1. problem unresolved with test coil (primary and secondary windings good). 2. cleaning up dizzy a bit before testing on car (lube etc..) stay tuned. 3. compression test next week, stay tuned.

test coil and test dizzy coming tomorrow morning sat 02-12-10. stay tuned for results.

I was at motorsports last weekend and spoke with Garret. I did not ask him about this years event but I asked him how business was in relation to the economy. He stated "we are doing very well with international sales". Perhaps are devalued dollar has struck a bargon for international z car owners? Not suggesting anything but we can all agree that times have changed economically here in the states this past year. Makes one think? What would I do as a business owner in these times? Park, no park, I will be at this years meet. best regards John

Funny you bring this up fast woman, as you have already read, I will be getting a test coil this weekend. What is funny is that I am also getting a test dizzy (1978 the one that cam with this exact motor, I gave the dizzy to my father as a backup for his 1975 z as I wanted to keep my single point set up)(so much for his back up ). If it turns out that the coil is ruled out, I already will be purchasing the gm hei four prong for the upgrade(much cheaper and more accessible to find a gm hei control module in the event it goes bad). I have read many threads and have so decided to go this exact way if need be. my thinking at this point is not set on originality. If I have to get a new dizzy then might as well upgrade to electronic for same price range. ugh! funny though I might be using a gm product to run my car . question. you stated " I have it on good authority that I should beef up the + supply to my HEI unit". how do you plan on doing this? power it with a relay? please explain. oh, thanks for your input

it is true that I can probably find a 280zx e12-80 cheaper than a pertronix so if the coil is ruled out then that will be my next move. as far as the centrifugal (mechanical) advance on that dizzy, it can probably be adjusted to suit my set up but I will save that for another thread . I will be posted again on this thread after this weekend so stay tuned. thanks again for your input. john

adrian, guess I wont be workbenching my existing coil then, btw, very informative. test coil to be picked up this weekend . ten four on the capacitor(condenser), I thought I was missing something in the system. wow, diy spark tester very nice. will follow up with that for sure and keep one in my tool kit, thanks. sounds like a shot in the dark for a dizzy tester, I may make a few phone calls but it is more likey I will move towards the dizzy upgrade. very informative though. thank you for pointing this out. u are a wealth of info. again, the dwell time is a new term for me. what I have learned is do not gage dizzy stability on the steadiness of dwell angle. thank u. if the coil is determind to be ruled out, I then have one more question regarding ignition. Ideally, I would like to maintain my current dizzy (points) and upgrade to a pertronix system. in your opinion, if in fact the dizzy turns out to be the problem by process of elimination and not by bench testing the dizzy, is it concievable that the pertronix can/will compensate for this presumed worn out dizzy and to what extent and probabability? Is it just a matter of rolling the dice? I would really like to keep the current set up and just upgrade to pertronix, but if it is just to iffy then I will simply go with a new dizzy namely 280zx e12-80. thanks again for all your input on this matter. john

I am getting closer and closer to upgrading to electronic dizzy. thanks for your input mlc240z.

adrian, I have a test coil on the way this weekend as I refuse to spend the money unless I know for sure. In lue of this test coil, how do I fully test my existing coil at different rps while measuring primary current and secondary voltage? can I do this myselft? does this require a special tool other than a multimeter? 3-5 degrees of infrequent/flucuating retarding is definately a symptom. reviewing your comment produces the following- dizzy (see below), timing chain to be inspected after entire ignition system has been thoroughly and completely ruled out or problem solved which ever comes first. after all, timing chains do stretch over time and need to be addressed anyways. these symptoms are definately random. based on your response, I have checked/rechecked/replaced points, verified dwell angle (no change of dwell angle at any rpm noted on dwell meter, dwell angle wthin spec). capacitor? do you mean condenser? if not what is the capacitor? the condenser has been replaced, coil (planned to do as stated above), ground connections checked cleaned and a additional chassis to block ground added, voltage supply to ignition (coil) withing spec as tested with voltmeter of course. yes air and fuel have been ruled out at this point. 1. -bat to engine block has been checked. 2. variable spark tester has not been done, tool is cheap as I might pick one up, I expect the spark to be weak, this should be no surpise as least in my mind. things to do list. 3. yes dizzy is rock solid with no slop but cam has not been replaced and has lots of miles I am sure (cleaned cam with 1000 grit, just slightly I did not grind it). distributer test sounds like something that needs to be done by a skilled professional. does it require a special tool? can it be done at home? sounds like it may not be cost effective at this point. sounds like upgrade dizzy time (see above).( ironic, no dwell angle changes at any rpm see above, scratching my head). 4. I do not have an oscilloscope nor will I buy one, sounds like this will not be cost effective. sounds like dizzy time agian with regards to this intervention. yes I am aware that vacuum advance is primarly relevant to economic fuel at low rpm. thanks for pointing that out. so in review, test coil on the way, awaiting your response on how to further check my coil. may get variable spark tester but the results may not be surprising. distributor tester awaiting your response, sound like it may not cost effective, this pushes me towards dizzy upgrade. oscilloscope does not sound cost effective, this pushes me towards dizzy upgrade. new plugs in place. awaiting your response on capacitor? possible worn cam, this pushes me toward dizzy upgrade. chain will be inspected (see above) thanks again for your input adrian. John

first I want to thank each of you for taking the time to read/answer my thread as I know my statements are lengthy and wordy. I appreciate all your input. tlorber, I agree, but it is difficult to not start thinking of more complicated issues because its been about three weeks without positive results. thanks for pointing out that a stretched chain is less likey to cause wandering idle/timing variance as I was unsure about this (the chain will be looked at after and only after all ignition possibilities have been exhausted). there is no doubt that my set up could afford and upgrade to electronic. my primary concern is if the problem does exist outside the dizzy and I replace it with an electronic dizzy that covers the symptoms, will the underline problem come back to haunt me if the electronic dizzy fails to cover up the problem later on. for now, I will continue to persue the problem within the ignition system until I hit a wall or until it because not so cost effective at which point then and only then will I make the upgrade (that time seems to be coming very quickly at this point). John

hmm, noticed something different last night. when using the timing light (motor now set at 17 degrees), at idle around 700rpm, the timing mark on the balancer would retard inconsistantly back and forth approx 3-5 degrees from 17 degrees to approx 12 degrees. keep in mind the vacuum advance is plugged atm. and the mechanical advance has checked out fine. the dizzy is absolutly rock solid with not sign of play. NOW I AM THINKING TIMING CHAIN IS STRETCHED! AM I CORRECT IN SUPPECTING THIS?

It is always nice to get your input Arne. Along with your experience and the information recieved from multiple threads regarding this topic, I have decided to use the 1.5 coil w/o ballast.

grats on your resolution akorna. yes u are correct 4-5 inches I have fsm but stated wrong. my vacuum advance still kicks in at about 8 as a result of a worn lever connection (where the spring loaded diaphram connects to the breaker plate. it should be round at the connnection but is oval from wear and tear. the breaker plate however has been tested and otherwise works and does not stick). Based on what I have read and my knowledge base, this should not cause the problem I am having. also, a new port for the vacuum is coming soon. update. I purchased a new cap and placed a new ground from the chassis to block and recleaned all other grounds. problem still not solved!!! lastly I connect my mallory hyfire ignition box as a test to see if this would solve the problem. result, symptoms still occuring. The only thing left to fix/change at this point is a new cam on the dizzy. my thinking is the following. 1. how significant must a cam's lobes be worn in order to produce a symptomatic problem? 2 What kind of symptoms would develop? I welcome your input as this is the last of my ignition diagnostic search. my first mod at this point will be a pertronix and yes the mallory hyfire is coming of as it was just used as a test. compression check will probably come before pertronix.

Where did you purchase the reman dizzy and how much did you pay?

, what the heck were u doing up at 3:21 am for akorna . are you reviewing your threads frequently as well

Thanks for the response stevej dizzy is rock solid, no play back or forth, bearings present good. my mechanic friend looked and verified there solid as well. yes pertronix will happen as soon as I resolve this issue. I want to make sure not to cover a up a problem first. keep the ideas coming stevej

thanks for the response akorna . I am convinced the carbs are working fine, I rebuilt and tuned them myself. float levels set, throttle valves set (air flow), linkage not binding, pistons not sticking, etc.. 1. choke cables are disconnected atm (I did have an old none function set connected but I just purchased a new set of cables and will be installing them soon). nozzles are moving freely so this is rulled out. (btw, the car starts without difficulty in the morning) 2.vacuum advance is disconnected for one primary reason atm (soon to be fixed). the vacuum port/ported vacuum I believe its called (nipple at front carbi) is not on there. it came this way when I bought the car. it is sealed with silicon atm with no sign of vacuum leak. fyi, I no longer use the manifold vacuum after discovering through research, hands on vacuum pump work and recommendation from my reputable mechanic friend that this vacuum works differently and should not been used. I will be slightly drilling out this port at its carbi surface to replace the otherwise missing port/nipple with a piece of brass tubing (recommended by bruce at ztherapy). The advance mechanism itself (ie. breaker plate and spring activated diaphram that pulls the breaker plate) works when vacuum pump is applied (activates at approx 8 to 10 hg in vac and holds vacuum and breaker plate moves freely) and deactivates when vacuum is released. all internal dizzy parts have been been completely cleaned and lubed (including dizzy breaker plate). My brain is tired akorna ugh! 1. I am debating on buying a cap atm. maybe there is a hairline fracture in the cap that I am unable to seen. this could cause an unstable arc within the cap. I am scratching my head. 2. I am also wondering if there is a way to deffinatively determine if the plug cables are arcing at the block. I am running out of options. ugh! keep the ideas coming akorna

My set up 240z 1972 with stock ignition single point, L28 n42 block and n47 head, headers, stock SU's three bolt (rebuilt and all adjusted included float levels) car presently runs well but I suspect a weak ingition due to fouling plug 3, changes in plug presention with and without ballast (see below), noticable power increase with ballast bypassed (see below). 1. My consern is that I have an eratic misfire or eractic weak spark resulting in loss power. 2. manifold vacuum 12 hg inches consistantly at idle (too low for spec) (all valves have been adjusted cold and hot). no white smoke, barely noticeable black smoke at wot on freeway. 3. cylinders 6 and 5 presently show little if any change in rpm when spark plug wire is pulled off the spark plug. a. spark can be heard firing when spark plug wire is separted from spark plug six and five and held close to plug. during this separation process it is difficult at best to determine if a change in rpm is noted. In addition, an external rpm gauge is used to see rpm changes, none are noted during this separation process. 4. A timing light is used to verify if each cylinder is firing by way of using clamp (pick up) on each plug wire to see if it lights. at present all except cylinder number one lights consistanly. number one shows an erratic light during idle and shows consistant lighting with increased throttle somewhere around 1200 rpm and up thereafter. this method has shown multiple results/inconsistancy throughout my search of this suspected problem. current timing is set at 20 btd (I have tried 15 and 17 as well without success). anything below 15 the car runs noticeably poor and thereafter exponentially. 5. spark plug analysis (present gap 32, have tried 35 without success) a. with ballast in place all plugs have carbon build up. b. without ballast 6 good, 5 carbon, 4 carbon, 3 carbon, 2 good, 1 good. what I have done- 1. checked all ignition wiring (resistance, voltage, all normal spec) including to ballast, from ballast, to coil, from coil, to dizzy, in dizzy and to condenser. 2. plug wire resistance within spec, cap resistance good, new rotor, new points (dwell angle set, dwell angle rock solid at any rpm so no slop in dizzy), mechanical advanced cleaned lubed and verified in working order, vacuum advance capped atm( this should cause no problem), new condenser, coil wire resistance good, coil good (primary and secondary windings withing spec), ballast resistor withing spec. 3. no vacuum leaks noted spraying with brake fluid at intake. no vacuum leak noted with applying brake (ie. brake booster disconneted and capped at connection at present). 4. cleaned all contacts at battery. battery within voltage spec as well. what I have not done- 1. have not changed cap, cap does not currently show any crackes or carbon build up or any real sign of arcing, all 6 contacts have been cleaned. plug wires have been securely placed in cap! 2. dizzy cam has not been replaced, it was a bit rough so I cleaned it up with some thousand grit (just a bit, I did not grind it down!). 3. I have not added a motor to chassis ground wire. currently there is one ground from battery neg post to starter contacting block. there is an additional approx 10 gauge wire from neg post on battery conected to firewall (this has been cleaned and now has good contact and zero resistance. 4. have not done a compression check or leak down. Let it be noted that all symptoms are subtle and erratic and not isolated to any one cylinder at any given time. man I am tired atm, tired of working on her for about two weeks without a solid answer and tired because it is late and I need sleep. I hope I did not miss anything. fyi, for those of you who are going to recomend tonix I will be doing so only after I have found the problem as I do not want to cover my issue with a bandage. thanks Arne? Carl? Jimmy? any thoughts? forgive me if I have left you out thanks

Akorna I may be wrong but I believe the readings on your secondary windings is not at spec, at least not on a stock coil. I believe the resistance is suppose to be higher. Check the FSM. I dont know how that would effect the coil output though. good luck. John

Thanks for the info on the tach question Arne . Also, with your current set up 1.5 (stock coil) w/o resistor, have you ever burnt out a coil or have any other issues developed related to this set up? thanks John

This is also my consern Akorna before I purchase pertronix and bypass the ballast. I will be sure to follow this thread. thanks for bringing it up.