82 a/c vanagon running well stopped then no start

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boogie child
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82 a/c vanagon running well stopped then no start

Post by boogie child » Wed Jul 12, 2017 7:37 pm

82 a/c vanagon. Background: was on my way back from a camping trip, stopped and started van multiple times. Then stopped for a malt and 5 min later no start, cranks and cranks no start. Towed home. I have spark when i pull a plug and crank. I went through the FI manual (2 of them) ran the checks and everything checks out fuel pressure, double relay, etc all tests good until I get to injectors grounding I have power but no grounding signal. I get no flashing on my test light, check all the plugs on the ecu connector they test good, checked continuity between injector plug and ecu connector good, checked continuity coil white wire to #1 pin good this points to bad ecu, so I had it sent in and rebuilt, no change. So i guess either my test light didn't register grounding pulse ( i ordered a noid light) and i got another issue or ???? I'm rambling.
I will start from scratch on the weekend (frustrated). So any tips on most common cause for running well to no start with no warning? I had been driving for a couple of hours when this happened. Also when I am cranking it will backfire (?) blowing the vacuum hose from the intake to the decel
Valve. I saw somewhere to check the dwell on the green wire from points to coil I'll try that and any other things the guru's suggest. I am frustrated but i wont quit.

Kent
82 2.0 air cooled the boogie bus

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Amskeptic
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Re: 82 a/c vanagon running well stopped then no start

Post by Amskeptic » Wed Jul 12, 2017 8:35 pm

boogie child wrote:
Wed Jul 12, 2017 7:37 pm
82 a/c vanagon. Background: was on my way back from a camping trip, stopped and started van multiple times. Then stopped for a malt and 5 min later no start, cranks and cranks no start. Towed home. I have spark when i pull a plug and crank. I went through the FI manual (2 of them) ran the checks and everything checks out fuel pressure, double relay, etc all tests good until I get to injectors grounding I have power but no grounding signal. I get no flashing on my test light, check all the plugs on the ecu connector they test good, checked continuity between injector plug and ecu connector good, checked continuity coil white wire to #1 pin good this points to bad ecu, so I had it sent in and rebuilt, no change. So i guess either my test light didn't register grounding pulse ( i ordered a noid light) and i got another issue or ???? I'm rambling.
I will start from scratch on the weekend (frustrated). So any tips on most common cause for running well to no start with no warning? I had been driving for a couple of hours when this happened. Also when I am cranking it will backfire (?) blowing the vacuum hose from the intake to the decel
Valve. I saw somewhere to check the dwell on the green wire from points to coil I'll try that and any other things the guru's suggest. I am frustrated but i wont quit.

Kent

Hey, I'm rambling, too.
I am loathe to blame the ECU. So many times, it is something stupid, like the little #5 ground wire at the case, or a TS 2 connector, or a little terminal end getting pushed into the plastic connector block because of a subtle misalignment when you plug the component in.

Do you have breaker points? What is your dwell (BEFORE you check or adjust them)?
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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boogie child
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Re: 82 a/c vanagon running well stopped then no start

Post by boogie child » Wed Jul 12, 2017 8:57 pm

I was loathe also. Yes o points, I will check my dwell tomorrow BEFORE I check or adjust points, and report back. I checked grounds visually, I will check them a little closer. Thanks for the reply.
Kent
82 2.0 air cooled the boogie bus

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Randy in Maine
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Re: 82 a/c vanagon running well stopped then no start

Post by Randy in Maine » Fri Jul 14, 2017 6:34 am

Do you own a Bosch noid light? Now is the time.

https://www.amazon.com/OTC-7188-Bosch-N ... B000P72CMW
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Re: 82 a/c vanagon running well stopped then no start

Post by boogie child » Sun Jul 16, 2017 1:40 pm

Just checked dwell it's bouncing between 52 and 54. I can crank for less than a min before the vacuum hoses blow off the intake to the decel valve if that means anything. I did just get a noid light i'm gonna check to see if I'm getting a signal at the injectors that i was not seeing with my test light.
Kent
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Re: 82 a/c vanagon running well stopped then no start

Post by boogie child » Sun Jul 16, 2017 2:52 pm

Ok I do get a flashing signal at the injectors with a noid light. That sent me to the temp sensor it reads 1890 ohms ( the temp here is mid 80's so i think that's good). 52 to 54 dwell seems to be pushing the limits some but is that enough to cause a no start situation? What causes the backfire blowing the vacuum lines off. Let me tell you that wakes you up when you're leaning over the engine.
Kent
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Re: 82 a/c vanagon running well stopped then no start

Post by Amskeptic » Tue Jul 18, 2017 9:35 am

boogie child wrote:
Sun Jul 16, 2017 2:52 pm
Ok I do get a flashing signal at the injectors with a noid light. That sent me to the temp sensor it reads 1890 ohms ( the temp here is mid 80's so i think that's good). 52 to 54 dwell seems to be pushing the limits some but is that enough to cause a no start situation? What causes the backfire blowing the vacuum lines off. Let me tell you that wakes you up when you're leaning over the engine.
Kent

Recheck the timing/spark plug wiring for firing order. Seems stupid maybe, but check. Set timing statically to "0" with rotor pointing at #1 and #3's valves are verifiably moving simultaneously. Make sure wires count down 1-4-3-2 as you go around the cap. If you feel yourself chafing against the obvious, let it be known that the Universe punishes us for assumptions.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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Re: 82 a/c vanagon running well stopped then no start

Post by sgkent » Tue Jul 18, 2017 3:50 pm

the wires are on the wrong cylinder if you were working on that. You can also check for a carbon track in the distributor cap, and make sure the rotor is pushed down into the tab and not spinning on the distributor shaft. If those are Ok do a compression test.
TBone208 wrote: "You ppl are such windbags. Go use your crystal ball to get rich & predict something meaningful. Nobody knows what's going to happen. How are we supposed to take ppl who don't know the definition of a recession & "woman" seriously?"

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Re: 82 a/c vanagon running well stopped then no start

Post by boogie child » Tue Jul 18, 2017 10:53 pm

Amskeptic: I will check the wiring and firing order. Would the engine have started and run run well for hours with the cables out of order? I am confused by this next instruction. {Set timing statically to "0" with rotor pointing at #1 and #3's valves are verifiably moving simultaneously} I know how to set the timing statically but, what am I checking here or what am I looking for. Am I hoping for it to start at "0" static timing, or with it set to "0" with the rotor pointed at 1 is it also supposed to be at "0" with the rotor moved to 3, or am I actually supposed to get in and look at the valves? should I regap the points to get the dwell from 54 ish to closer to the mid 40's.
sgkent: I wasn't working on anything leading up to no start I was driving home from the beach in CA to my home in OR, stopped for a blackberry shake and no start. It had been running well with no symptoms. No start no jump start. I will check the rotor.
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Re: 82 a/c vanagon running well stopped then no start

Post by sgkent » Wed Jul 19, 2017 12:36 pm

There have been cases of strangers screwing with some one by flipping wires around. A carbon track can also form inside a cap and cause an occasional misfire. That is why I suggested checking for a carbon track.

The air cooled engines are prone to dropping valve seats. The usual goes like.... I was just humming along and there was an occasional misfired and pop into the intake manifold. One blew a hose off.... That is why I suggested a compression test,

You can also try running premium to see if that slows or stops it. If that is the case then glowing carbon in the combustion chamber is causing misfires.
TBone208 wrote: "You ppl are such windbags. Go use your crystal ball to get rich & predict something meaningful. Nobody knows what's going to happen. How are we supposed to take ppl who don't know the definition of a recession & "woman" seriously?"

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Re: 82 a/c vanagon running well stopped then no start

Post by Amskeptic » Sat Jul 22, 2017 9:10 am

boogie child wrote:
Tue Jul 18, 2017 10:53 pm
A) I will check the wiring and firing order. Would the engine have started and run run well for hours with the cables out of order?

B) I am confused by this next instruction. {Set timing statically to "0" with
1) rotor pointing at #1
2) #3's valves are verifiably moving simultaneously}

I know how to set the timing statically but, what am I checking here or what am I looking for. Am I hoping for it to start at "0" static timing,

a) I hate to. send people off on a wild goose chase, and no, your engine will not have run for hours with the wires out of order. But, to narrow down this vexing problem, it is good to know what it is NOT as well as what it is. I cannot know from here if you have flitted all over everything as you checked the engine, so i just wanted to verify the basics.

b) this step is Basic Start Protocol for those who have accidentally gone nuts and pulled distributors and done godknowswhat in their investigative fever. This step guarantees that you have the rotor pointing at #1 to fire while #3 is up on exhaust and about to go down on intake. You know that 1 and 3 share the same timing mark. People frequently will have wires off 180* and they are trying to start an engine on the exhaust/intake overlap. Your situation, however, looks like it came up out of the blue and is causing backfires in the intake? Heck, adjust your valves! You might have a tight or leaky one all of a sudden.

c) since I do not know your mechanical proficiency, I sort of have to guess at things . . .
Colin :blackeye:
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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Re: 82 a/c vanagon running well stopped then no start

Post by boogie child » Tue Aug 15, 2017 4:44 pm

Have been very short on time but i verified the firing order (have not had time to check valves). I was able to put on new points and condenser that I had in stock, and I got the dwell to 44 (it had been at 54 to 56 with a point gap of about 11 and a pretty cruddy looking condenser). Set static timing to 7.5 btdc . Still no start but no more back fire. It sounds and feels like it is closer to trying to start (I know how highly technical that sounds). Took a step back and started checking some things. I was worried that I might be draining battery but it tests at 12.3 volts between the terminals, which I believe is fine. So I check the positive terminal at the coil and with the key on I'm only getting 10.7 volts when I crank it drops to about 8 volts, which I believe is not fine. I will still be checking the valves to see if they are in the correct position. But where do I go with finding the cause for not getting 12 volts at the coil, which I think should stay a constant 12 volts with the key on or cranking?
Kent
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Re: 82 a/c vanagon running well stopped then no start

Post by Amskeptic » Sun Aug 20, 2017 10:46 am

boogie child wrote:
Tue Aug 15, 2017 4:44 pm
Have been very short on time but i verified the firing order (have not had time to check valves). I was able to put on new points and condenser that I had in stock, and I got the dwell to 44 (it had been at 54 to 56 with a point gap of about 11 and a pretty cruddy looking condenser). Set static timing to 7.5 btdc . Still no start but no more back fire. It sounds and feels like it is closer to trying to start (I know how highly technical that sounds). Took a step back and started checking some things. I was worried that I might be draining battery but it tests at 12.3 volts between the terminals, which I believe is fine. So I check the positive terminal at the coil and with the key on I'm only getting 10.7 volts when I crank it drops to about 8 volts, which I believe is not fine. I will still be checking the valves to see if they are in the correct position. But where do I go with finding the cause for not getting 12 volts at the coil, which I think should stay a constant 12 volts with the key on or cranking?
Kent
Fuel injection shuts off at 10.7 volts. You need a fresh battery / charge for sure.
If there is a serious voltage drop during cranking, you will need to investigate the starting circuit for excessive draw, like Elwood's starter here. Looked fine on the outside:

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BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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Re: 82 a/c vanagon running well stopped then no start

Post by dingo » Mon Aug 21, 2017 10:38 am

Do a volt-drop test to determine where the leakage is...Set volt meter to 2V setting and attach leads to various points on the positive loop. then the negative loop. example: one lead at batt pos and the other at starter pos...crank and see how much voltage goes thru the meter instead of the cable..do a search on 'volt drop test'..it will help isolate the problem wire or connection or..
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Re: 82 a/c vanagon running well stopped then no start

Post by boogie child » Wed Aug 23, 2017 6:52 pm

I am trying to figure out the volt drop test to find the voltage leak. I would also like to test voltage upstream from the coil but my ability to read wiring diagrams sucks. I can't figure out what actually feeds the positive terminal of the coil. It has 2 wires that disappear into the wiring harness, they are black it seems, but on the wiring diagram it looks like there are supposed to be wires to the ignition control unit the horn and the double relay. Can anyone clear up the path of the power from the battery to the coil for me so I can check step by step to see where the loss occurs? Also where the most common points of voltage loss would be, I would like to test in the most logical order but I don't know where to start. I think I understand the volt drop test for the battery terminals and the starter contacts, so I will start there, but I don't know where else to test for a drop. Hope my confusion makes sense to someone who can help give me some direction. Thanks kent
82 2.0 air cooled the boogie bus

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