van won't start, looking for ideas

[flying kurbmaster]

Hi guys my 1986 Kurbmaster GMC, with a 292 six cylinder and carburetor won't start. I was out and about the other day it was idling and running fine, filled it with gas then I was checking the lights before setting out on a small journey when the engine died, it did not sputter, it was like someone just turned it off, I am thinking electrical. I am thinking coil and I also read something about a modulator, I can see a small black box 3 x3 inches by 3/4 inches next to the distributor and was wondering if this is the modulator or are modulator only for fuel injected engines. Also I don;'t see a coil is that inside the distributor or is that the square piece on top of the distributor, is there anyone familiar with this era of GM. or any other ideas would be  appreciated,  I know sometimes if you let the coil or  modulator cool down they work  I am off to try this.

 

[Patrick46]

Awwww man....

Electronicals???

Nope....I'm out.


Good Luck brother!

 

[ramblingvanman]

The coil is sitting on top of the distributor. Do you have any way to check for spark? Do you have any carb cleaner? What tools/equipment do you have? Do you have anyone who can crank the engine while you check for spark? Do you have a multimeter?

 

[ramblingvanman]

Just in case we keep missing each other, here is a quick primer on what you need to do. It is written for the non-technician. It is not exactly for your vehicle, but the ignition system should be the same or very similar. If it isn't, please take and post a pic of your distributor so I can see what you have.

http://easyautodiagnostics.com/gm/4.3L-5.0L-5.7L/distributor-mounted-icm-tests-1

 

[Gary68]

on h.e.i. distributors the coil is the square thing bolted to the top

to check spark,pull a spark plug,plug it back into its wire,ground it and turn over engine and see if spark plug sparks,be very careful not to touch when turning over it will shock you bad,use a piece of wood or some thing with rubber/plastic handle

if it was just after you filled up it could be water in the fuel too

 

[ramblingvanman]

on h.e.i. distributors the coil is the square thing bolted to the top

to check spark,pull a spark plug,plug it back into its wire,ground it and turn over engine and see if spark plug sparks,be very careful not to touch when turning over it will shock you bad,use a piece of wood  or some thing with rubber/plastic handle

if it was just after you filled up it could be water in the fuel too

Possible but unlikely to just cut off and not try to restart. Should have started out by missing, stumbling etc... That is why I was asking about carb cleaner so he could try to start the car with that by spraying into the carb while cranking if he actually has spark.

 

[Gary68]

true ramblingvanman

also if you find you have no spark,start with checking fuses then electrical connections and wires before you start buying parts

 

[ramblingvanman]

also if you find you have no spark,start with checking fuses then electrical connections and wires before you start buying parts

Agree, we need to go step by step before wasting any money changing parts.

 

[Baloo]

Take a spark plug out and hook its wire back on it and lay it on the intake where the metal portion is making contact with the intake, crank the motor, if there is no spark on that plug then you have an ignition problem. If there is spark, check fuel. Let's assume there is no spark, so there are two connectors sometimes three on an hei distributor, the one single wire on the right should have 12v when the ignition is switched on. The one on the left is the tach wire, the plug behind those two is the ignition module/points if it is old school. If there is power at the ignition wire, remove the distributor cap and set it off to the side. Crank engine, make sure the rotor is spinning, if not the cross pin in the gear is broken (not uncommon). If it is spinning, time to check the electric ignition pickup (should be for your year). This is where a good multimeter helps. What you are checking for is that there is a dwell cycle (on-off-on-off) when rotating the engine. A picture of your distributor and associated components would be helpful for this step.

 

[flying kurbmaster]

ok so I opened it up I found the coil, under a cover on top of the distributor, that black box thing next to the distributor has something to do with the anti smog system looks like it has been disconnected for some time, so I checked for spark with a plug out and grounded, nothing, checked with screw driver in plug wire and grounded, nothing, checked for fuel, lots of fuel, spewing in carb, engine did not stutter or hesitate when it shut off so I still think it is electrical. I don't have a volt meter so I used my test light and I have power to the wires leading into the coil, I will go and check if the rotor is turning with the engine,

 

[66788]

All an engine needs to run is fuel, compression, and spark.

Check those and you'll find the problem.

 

[flying kurbmaster]

ok the rotor is turning, so that seems ok, I found the ignition control module it is located under the rotor. I suspect either the coil or the ingnition control module are faulty unless someone has another idea... I am wondering how much they cost and if not too much I might get both and change one at a time and keep the other for a spare.

 

[ramblingvanman]

This is where your multimeter would come in handy to check the primary and secondary on the coil for continuity.

 

[ramblingvanman]

ok the rotor is turning, so that seems ok, I found the ignition control module it is located under the rotor. I suspect either the coil or the ignition control module are faulty unless someone has another idea... I am wondering how much they cost and if not too much I might get both and change one at a time and keep the other for a spare.

There is a test you can do with your test light. There should be 2 plugs visible on the outside of the distributor. 1 with 2 wires, 1 with 4. The one with 2 should have a pink wire and a white wire. The pink wire should have a constant 12vdc with the key on. The white wire should have a pulsing 12vdc when cranking or with the engine running. Test the white wire while cranking. If the pulsing voltage is present, the ignition module should be good.

 

[flying kurbmaster]

mine is a bit different then what you are showing I only have two wires going into it or coming out, a green and a white, neither have power, on the other side there is another connection with two prongs that goes into another plastic plate that has 3 wires coming into it from the outside of the distributor, next to the plate is condenser I think or at least it looks like a condenser, there is power to the two prongs when ignition is on but no power to the other side with the green and white wires. the three wires lead back to the coil connectors where there is a few more wires one is grounded and the others head back into the main harness.there was also power at the coil on two of the wires when ignition is on, the third one was grounded

 

[highdesertranger]

ok no spark, and you have 12v to the distributor. so now you need to check the coil, and the pick up, there is really no test for the electronic brain on GM vehicles. but if you can eliminate the other 2 you can safely assume it's the brain. a manual will give you the specs and how to check the coil and pick up. do you have one? when the vehicle gets old it's very common for the wires in the pick up to go bad. will see if I can post a link to a shop manual to show you the test and yes you will need a multi meter. highdesertranger

 

[ramblingvanman]

mine is a bit different then what you are showing I only have two wires going into it or coming out, a green and a white, neither have power, on the other side there is another connection with two prongs that goes into another plastic plate that has 3 wires coming into it from the outside of the distributor,  next to the plate is condenser I think or at least it looks like a condenser, there is power to the two prongs when ignition is on but no power to the other side with the green and white wires. the three wires lead back to the coil connectors where there is a few more wires one is grounded and the others head back into the main harness.there was also power at the coil on two of the wires when ignition is on, the third one was grounded

Can you post a picture of exactly what you have?

 

[flying kurbmaster]

sorry no pictures at this time, a long story, I will go pick up a multi meter tomorrow, I had one but it fried, a few months back. thanks for all the input...looks like I will be camping in an awkward place for a few days.

 

[highdesertranger]

sorry it took me awhile but here is your shop manual. it's a pfd and covers all GM trucks and vans for 1986. I would down load and save it to your computer. http://www.dieselplace.com/forum/7103466-post5.html . the ignition starts on page 821. highdesertranger

 

[highdesertranger]

I can get most of the older GM shop manuals online in PFD. if any body else needs one let me know. kurbmaster if you need to replace the pick up let us know I can walk you through give you some tips. highdesertranger