Toyota Trucks: NO SPARK: 88 4Runner

"FriendlyFire19" <com> wrote in message
news:talkaboutautos.com... 
parked for two hours and it was about 
started. It ran extremely rough for about 10 seconds and then died. The
engine cranks over with ease and is not frozen. It will sputter a little bit
but not much. 
connections and made sure they were tight and inplace....visually everything
seems ok. 
is it related to the frigid cold temperatures. And obviously...what can I do
to get my truck running again. 

My money is on your ignitor. If not that, your coil is the next in line as
the culprit.

Check the diagnosis system. If the problem is with your ignitor or coil, it
will have at least one code 14 stored in memory, meaning the ignitor failed
to signal the ECU several times running.

I have had two Toyotas go dead as doornails as you have described (no fire)
and, both times, it was the ignitor. But, check the code first to be sure,
this part is expensive and they either work or they don't. BTW, if you have
to replace it, go with a junkyard - you will get it for half the price and
it could last as long as a new one.

Luther

Maybe you'll get lucky and it'll just be a bad distributor cap and/or rotor. No
harm in checking out the easy stuff first.

Chris

"Luther" <net> wrote:
 

That's what I thought, when my '89 3VZN wouldn't spark/start! Now I
have a spare ignitor ($70, "used").

After the $pendy ignitor didn't make it run, I applied systematic
diagnosis: I started unplugging stuff! With the Air Mass Meter and
Throttle Position Sensor disconnected, it STARTED! I had a shorted-out
Air Mass Meter! I got one from a Toyota sedan at UPullIt for $15, and
good-to-go ever since!

the details: the 3VZN AFM's are different than the RN Series, and are
difficult to locate, used ("new" is out-of-the-question!). I found the
ohm specs in the FSM and kept scrounging (ohming-out units at UPullIt)
until I found the right one. They ALL look the same,even Subraru, just
different ducting, and resistance specs, of course. And, there were NO
codes generated by this problem! So much for OBD-I! Apparently there
is one wire that carries a reference voltage from the ECU to the AFM
and TPS, and if it is grounded out, you lose spark, without codes
generated.

Good luck! (NO fun working in f**king freezing weather!!)

"Ms. Manners" <so.polite.edu> wrote in message
news:com... 

He asked for the most probable cause and I gave my best guess based on the
fact that it just quit and he has no fire.

But that was just a SWAG. The important part of my advice was that --
before buying anything -- he should CHECK THE DIAGNOSIS SYSTEM (ie -short
out terminals T and E1 on the check connector and count the number of times
the "check engine" light blinks.) In situations involving no ignition, this
system is excellent at pointing out the culprit. As a matter of fact, it
should have diagnosed your faulty air flow meter as well (code 31 or 32),
saving you the $70 on an ignitor you didn't need.

The diagnosis system can only help us if we ask it to.

Luther

"Luther" <net> wrote:
 

I totally agree, Luther.

In my ("rare occurrence") case, though, I was stymied by the LACK of
error codes. The AFM "may" have clobbered my IDL input. (Sensing an
open throttle switch will prevent the ECU from running self
diagnostics.) But that's a guess...

Right! CHECK FOR ERROR CODES FIRST!

Jeff

"Ms. Manners" <so.polite.edu> wrote in message
news:com... 

Too bad you couldn't get any codes. Touché on your diagnosis and repair of
the problem, however. Your approach was impressive.

I have heard others say they cannot get codes out of their vehicles.
Strange - mine spits 'em out like there's no tomorrow. It told me just
yesterday that my a/c switch circuit was open - I knew that anyway, but was
appreciative on the heads-up nonetheless.

So Cory, what was the verdict?? You've got my curiosity up.

Luther

I couldnt get any codes out of the diagnosis system. I thought it might be a bad ground so I grounded t to the negative batt terminal and still nothing (shit). I took out my multi-meter and went crazy testing every possible thing i could.....still nothing.

I do recall a while back trying to set my timing and jumping t and e1 did not seem to have an affect on my engine idle...although the timing seems to be perfect. I am skeptical about the diagnosis system. At this point I am running out of ideas.

Any thoughts???

thanks

"Luther" <net> wrote: 

Here is excerpt from an SMP Technical Note:

TOYOTA PRE-OBD II-CHECK ENGINE LIGHT ON-CANNOT FLASH TROUBLE CODES

Normally, diagnosing a Toyota vehicle that has a Check Engine light
illuminated is a straight-forward procedure. Typically, we jumper the
appropriate terminals to read the flashes of the light on the dash.
But what should we do if the light does not flash?

Let's review how the system operates. The check-connector on early
models were typically two wire connectors located in the engine
compartment. The two wires are designated: T and E1. T is the test
terminal that is connected to the computer. The E1 terminal is a
ground. On later systems, these two wires are located in a multi-pin
connector, labeled "Diagnosis", located by the front strut tower. This
connector has a flip-up cover that has a label for terminal
identification. This connector contains the T or TE1 terminal, along
with an E1 terminal.Voltage on the T or TE1 terminal should be 5 or 12
volts with the ignition key in the "On" position. The absence of a
voltage reading is an indication of an open circuit between the
connector and the ECM, or a bad ECM.

If we have the proper voltage at T or TE1, then the next step is to
ground this terminal directly to the E1 terminal. If the light does
not flash, then try the battery negative terminal instead. If the
light now flashes, then terminal E1 is not grounded properly.At this
point, if we still cannot get the light to flash, then we must check
the Check Engine light circuit itself.First, locate the ECM and
disconnect its connectors. Next, turn the ignition key to the "On"
position. The light should not be illuminated. If the light is
illuminated, then the circuit has a short to ground that must be
repaired.The last item to check is the IDL input to the ECM. The IDL
input informs the ECM when the throttle is opened or closed. This IDL
input comes from the throttle switch that is basically an "On-Off"
switch. The throttle switch is a black box assembly on the throttle
body, opposite of the mechanical linkage. It is attached with two
screws, and it is adjustable. The ECM will supply a voltage signal
(5,9,10, or 12 depending on the system) on the IDL wire. The switch
will ground this signal at closed throttle. The voltage value is not
critical, however the switching is. Self diagnostics will not be
allowed if the throttle switch is open. A quick check with a voltmeter
will reveal if that switch is closed. If you measure zero volts, then
the switch is closed. You should measure voltage when the throttle is
opened.

Items that prevent the proper input to the ECM are: dirty throttle
bodies that prevent the throttle from closing, improperly adjusted
throttle linkage, sticking dash-pots, or an out of adjustment throttle
switch itself.One other point to keep in mind is that the same
terminals you use to check codes, are the same needed to set basic
ignition timing. Proper IDL input is also needed, otherwise, basic
ignition timing cannot be properly set. A couple of points to keep in
mind when setting basic timing are: when you jumper the T or TE1
terminals to E1, you should see a reduction in engine speed and the
Check Engine light should be flashing.If you do not see this, ignition
base timing will not be set properly.

John Rogers
Asian Specialist
(From: SMP, Inc. "Engine Controls and Fuel Systems Fall 2002)