I have a 1985 Chev20 Van with a 305. I have power entering the
Cap/Rotor but no Spark. I have changed the Ignition Module and the Coil
Pack on top of the Cap....all to no effect. THe Engine with turn over
but has no spark coming down the wires whats so ever. Any Help will be
No, I am talking about the pickup coil in the base of the distributor
that send the trigger signals to the coil to fire spark. It is next to
the 8 lobed reluctance "wheel" that triggers it as each lobe passes
I agree with snowman.
i had a 755 chevy van quit in the mountains.
I hitch hicked 30 miles to bet a new module.
had to go back gor a new coil which measured sfhorted and a pick uo coil
which was the last to install and it then started (my lady fished for two
days while i traqveled to stockton and back twice) hehehe
i then rebuilt a whole high energy ignition distributer complete and carried
it into the mountains with three different vehicles i drove under different
circumstancses. never had to use it though.
finallt sold it after selling all my chevy 350 vehicles.
SnoMan, thanks for the replies...and I know what you are talking about
now...after I read your reply I went home and a buddy and myself went
and replaced the pickup coil (I had thought it was a condensor). Still
no spark. This van was completely gutted and repainted a year ago and
hasn't been started since. I did notice though....a harness located
under the drivers seat with nothing attached to the end of the harness.
This harness then goes under the floorboard...back to the Cap/Rotor. I
beleive I am missing an important computer or module for this van. I
remeber taking it out over a year ago and noticing it was rusted to
heck. Perhaps I threw it out...I cant remember. Basically...what is
this box...is there a way to by-pass it...or am I holding on to a huge
THe Knock/Spark control module....is this one componet located under
the driver seat? THis is on a 1985 Chev20 Van...with a 305 cubic inch.
I want to make sure I know what the exact name of the part is...and
where I might be able to obtain a used one. Thnks agian for all of your
Well on a TBI P/U it is mounted on engine intake on a bracket and it
is maybe 3 x 3 x 1 inches. In a van, space is tight and it could well
be located beneath the seat. Get one at like Advance Auto and you can
take it back if it not it. Sorry that I cannot be more exact but I do
not have a van here to look at to see for sure. It will not make spark
without one though
Hey Sno, would a 1985 Van have TBI or a Quadrajet?
If it has the same ignition system as my '86 K5, the ESC/ECM can be
To the OP: Does the ignition module have 4 or 5 pins?
Also, when the key is in the "on" position, do you have 12vdc on the
feed coming into the driver's side of the distributor?
305 were the first with ECS even before they were TBI injected. THe
whole theory with ECS was to allow for higher compression with some
knock protection. disable it you will have to retard static timing
even more to prevent knock and reduce MPG too which it not to wise
with today fuel prices.
By Passed worked fine. Although Timing is off the scale, it seems to be
runnig fine so far. As for the knock sensor...I just gotta start
putting in premium gas. Thanks all for the tip...saved me a few hundred
Yes... You'll need to retard your timing a bit is all. Basically,
treat it as a 1st generation HEI distributor (non-computerized). You
may want to check the timing specs of an older van to find a good
starting point for your initial timing. Remember,
non-computer-controlled distributors don't have a way of
self-correcting for spark knock.
You can further compensate with an adjustable vacuum advance module and
a different set of weights and springs in order to get the timing curve
that works best for your application. If you tow things, or carry
heavy loads, you may need to tweak it to avoid pinging. I'm not sure,
but it would seem logical that the weight and spring requirements may
be different for a distributor that can electronically regulate itself.
The parts are cheap and readily available, so experiment as needed.
Either way, I'm very happy to see that you're up and running again!
THe bottom line is though that with todays and tomorrows fuel prices
you want maximum possible efficecny from engine not having to run it
retard to prevent knock under load. On my 89 4x4 burb I run 8 BTDC and
93 octane and it will ALWAYs get 18 to 19 MPG on trips (it has a 40
gallon tank and will cruise 600 mile between fills with a good
reserve) best it ever did with 87 and stock timing was maybe 15 and
usually less and it was a slug on hot days and wanted to ping even
with spark control under load. Now it never makes a sound and runs
really well. Been running it this way for many years too and plan to
for at least another 6 years until kids finish college. It is not a
daily driver and is still pretty cherry. It will never see another
tank of 87 as long as I own it no matter how high fuel prices get.
93 octane makes more financial sense now more than ever. If you look
at the difference in price in terms of a percentage, 93 costs "less"
than it used to when 87 was $1.00 per gallon. It used to cost 15-20%
more to use 93, not so nowadays.
I only run 93 octane and have for years. For vehicles equipped with
knock sensors, it makes even more sense, as the engine will allow more
advance for better power and efficiency. So I do believe
(unsubstantiated) that running 93 octane fuel will get me better
mileage and performance.
My girlfriend's 2006 Tahoe runs *much* better on 89 than 87...we can
both tell a difference. She hasn't tried 93 in it yet. She still sees
the cheaper priced 87 and thinks cheaper must be "as good".
An experimental Saab engine had variable compression, and produced more
power and did so more efficiently as octane rating increased. In fact,
it reportedly ran the best when E-85 was used.
I guess you know that I share these veiws but I have seen MPG gains
from it in several vehicles. And yes today 93 octane is 5 to7% more
tops here and even 89 is maybe 3% more and even a 3% gain in MPG (or
about from 20 to 20.6 would break even on the cost of 89 orver 87. In
theory it would be possible to run very high compression if you used
only E85 (around 12 to 1 or so) because of its high octane. Modern
engine are really hamstringed by the need to "tolerate" 87 octane
because of John Q. Public's affinity for it. If it was removed from
market and only 89 and 93 or only 93 they could build engines with a
lot higher compression in new vehicle and this would improve their
thermodynamic efficency and therefore their MPG too but this cannot
happen as long as 87 octane "tolerance" is needed. WHen direct
injection for gas engine makes it main stream it will allow for even
higher CR's because injecting it just before ignition cools the
mixture some and reduces octane requirement a bit for a given CR.
Heh... Sno, buddy, you're preachin' to the choir.
If E-85 were actually widely available, I'd rebuild the K5's engine
with that fuel in mind. More power, emissions-compliant, cheaper
gas...what's not to like about that?
I thought it'd be fun to build a high-compression, E-85-burning
4-banger or small Buick 231 V6 just for kicks...and stick it in
something tiny, like an MG or Fiat.
It's exactly as you say. If we could bump up the compression to get
more power with the E-85 gas, we could then build smaller, high
performance engines to do the same task using less fuel.
What happened to the days when REAL engines were built with high-octane
fuel in mind??? Remember the label next to the shifter on the real
monster Corvettes in the 60's?? It specified that it *had* to use
I grew up street rodding in the late 60's and into 70's and I had a
1972 GMC 3/4 ton 4x4 with factory dual tanks and a SM465 that I got
when it was about a year old and souped it up some too. It was a trip
because 4x4's were really very rare then and powerfull ones were even
more rare. I almost put a warmed up 396 in it and I wish I had to look
back on now. I had a 69 Implala SS with a 396 that I was kinda of fond
of for several years until the frame started to rust out where control
arms for rear axle hook to frame. I beefed it up before it failed and
then sold it. (that was the engine I was thinking of using in my truck
and scraping the car) Back then you knew who the cheap skates were
when it came to buying gas as you could hear them rattling away from
lights. Some modern engines have some good power but it still nothing
like a old BB with 11 to one CR and a nice intake and cam. You try and
tell that to someone that never saw them in their prime though and
they think you are BSing them. I drove and road in some down right
scary cars back then HP wise. I knew a guy that had a 67 GTO with a
blue printed 421 tripower and a 4.56 rear axle that could run 12's all
day with street slicks and a bit faster with race slicks. Those old
tripowers were scarey stock and even more so souped up. He was
untouchable on street by all except a guy that had a 67 camaro with a
roots blower on a warmed up 427. It was a 10 second machine wearing
track slicks and could easily pull front end on street. Oh the good
old days. Time to get off of soup box.
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