Subject: Ignition Trauma!!!
Date: Thursday, 10 Jun 1999
To: BEAN6@aol.com
BEAN6@aol.com wrote:
Hello Mr. Z Doc,
You helped me once before when I was trying to figure out if my timing was
right on the '82 280ZX I had just gotten. Thanks again for that. You
were right on.
Now I've got a more serious problem, and it's intermittent, so I can't even
show it to a mechanic - if I even had one nearby. So, as a last resort,
I come groveling to you, the Z Doctor. Would you be willing to help again?
My car starts and runs fine when it is cold. I usually will not have any
trouble on my way to work - 10 miles on freeway at 60 - 70 mph. On my way
home, when the heat of the day is up and the Z is running at normal temp,
the engine starts cutting out. It may die for one second or several seconds
or up to 10 seconds, but it will restart (if I leave it in gear) and resume
running fine. Then it may happen again, several times. Once I get off the
freeway, it seems to get worse as I limp home on the side streets, stalling
at several stoplights and running fine much of the time. 20% of the time
when it happens on the side streets, and I have come to a full stop, I will
have difficulty restarting the engine. It will crank, but it won't ignite.
I originally thought it was a fuel problem, so I replaced the filter and
ran some injector treatment through it, to no avail. When the car dies,
the fuel pump, which is pretty loud, keeps going for a second or two, so
I'm thinking the fuel is getting there.
I've shifted my thinking to focusing on the spark, and tonight I put in
a new coil, just on a prayer. On my test drive, it jumped and stalled again,
after it was warmed up, but not really hot. My inner diagnostician finally
burst out and I got out my timing light and started putting the plug clip
thing on various parts of the ignition system and tried to make it stall.
I got lucky and had a time where it wouldn't catch when I cranked it, and
I found out there is no spark going to the plugs, plus there wasn't any
pulse going from the coil to the distributor. Then it caught and ran fine
for awhile.
Next time it crapped out, I put the pickup on the small wire running
to the coil, and it wasn't pulsing either.
So now I'm thinking it's something upstream of the coil, which is an area
I have no knowledge of.
Here are my questions:
1) Are you still reading this?
2) Do you agree that the problem is upstream of the coil?
3) What's up there?
4) Does whatever's up there tend to cause this type of problem?
My manual said something about an IC Ignition Unit. Do you think this could
be the problem?
I really hope you have a chance to respond, since I know it's just a matter
of time before I get stranded out there. I hate it when that happens.
Thanks alot,
| Bob Smith |
bean6@aol.com |
Hi Bob, Doc here, I'm sorry to hear that you are having
problems with your 280ZX. Lets see if we can narrow it down for you, and
possibly hit the mark with an Internet diagnosis from the Doc. By the way
I'm not the Z Doctor from Richmond,
just Doc.
First of all you sound like you are on the right track and have narrowed it down to a No Spark situation. That is good because this is an important question to be asked since you are hearing the fuel pump run then that rules out potential for multiple problems. Remember that you need three things to run.
1.Compression. 2. Fuel. 3. Spark. for the basics.
Since your ZX is a non Turbo it has an EFI system and the ignition is
controlled by the ignition module located on the outside of the distributor.
The pickup is located inside of the distributor and has a very fine sized
wire winding component that is the input signal, or ac current generator.
This little inexpensive piece has the characteristic of going open in the
winding when it gets hot and thereby not producing the necessary signal
for the ignition module (black piece) located on the outside of the distributor.
The ignition module is the expensive part of this ignition system. There
are two wires that attach inside of the rubber boot, one red and the other
green, on the backside of the module. There are only two screws mounting
the module to the distributor.
The good mews is that you can switch the module with a stubby screwdriver
without removing the distributor from the engine. This means that you will
not have to retime the engine. The Best News is that any black ignition
module from lets say a 210 will work on the "ZX"! The replacement
for the pickup is a little more sensitive to facilitate it's removal, but
can also be done in the car. The recommendation it for you to find the
module from a known good running car and replace it for the test. If it
still quits then you know that the pickup must be replaced. Do not try
to install a used pickup. Buy a new one from a good parts store that handles
Standard Ignition Parts. DO NOT Buy junk brand stuff. The other option
is to get the part from your Local Nissan Dealer. You will want to check
the prices so do some comparison shopping on the ignition module and the
pickup.
Your parts availability in your location is the key here. Sometimes the dealer is not a close source. You can call and ask the local parts store if they can get you Standard Ignition parts, because the parts in their boxes come from Japan and are the factory parts. I hope that this clarifies the situation for you, with some background too.
There is one other thing that needs to be checked out for a possible
like scenario for the situation you have described. Located in the lower
side of the cylinder head between #5 & #6 spark plugs is a two wire
EFI Type cylinder head sensor. Carefully remove the wire clip and disconnect
the harness. Inspect the connections for the green crud that will cause
the sender to go open with too much resistance and if it is present get
some WD40 and spray with the tube into it and the sender too. Carefully
use a safety pin of very small screwdriver to scrape off the crud and then
flush with the WD40 again. Reconnect and test
the running condition.
I hope that this will help you get it back On the Road Again!
Are you a ZONC Member? Join ZONC Z Owners of Northern CAlifornia
ENJOY THE RIDE IN YOUR "Z"!
ZDOC OUT
Subject: Ignition trauma resolved
Date: Sun, 12 Jun 1999
From: BEAN6@aol.com
Hello Doctor,
Thank you so much for respopnding to my previous inquiry. Mine was the 280ZX with heat related intermittent sparkus interruptus.
I had replaced the coil and the head temp sensor, and on your fine advice, replaced the little coil thingie in the distributor. Cranked it up and went for a ride. No sign of the problem, so I went storming through the back roads, only to have it happen again when I was about 5 miles out. That really pissed me off. I've gotten good at limping home these last few weeks, but may dander was getting up now.
This morning, armed with a wet sponge wedged against my ignition module and a bucket of water to try to keep it cool, I went out to find a new module at one of the local junk yards. Stalled about 25 times along the way. Had to take all the intersections on a running start. On my third yard, a guy reached under his counter and pulled up a Maxima distributor that had the right module on it. Thanks for cluing me in on that interchangability trick.
Everyone there agreed that a module will NEVER cause intermittent
trouble . When they go, they go. Oh well, it was my last resort and I was
gonna try it anyhow. Got the guy down to $50, went home, plunked the box
onto my
distributor, and zoomed away. My heart sunk when the Z bucked once about
5 minutes into my drive, but it never happened again. Maybe I hit an armadillo
(!!??...ed.) or something. I drove it all day and never got another stall,
so I'm declaring it fixed.
Thanks again for the help. I fully intend to join ZONC.
Bob Smith
Santa Rosa, CA