80 Vanagon Engine no start after new distributor

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maxsvetlik
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80 Vanagon Engine no start after new distributor

Post by maxsvetlik » Sat Jun 09, 2018 2:09 pm

Hey folks

I'm having some trouble starting my 1980 Federal Vanagon, which had its engine rebuilt in January. It ran great, but had pretty poor gas mileage (10-12mpg) so a couple weeks ago I replaced the air intake to manifold boots, and the S-boot, which I had not replaced during the rebuild (the old boots had several cracks)

Started the engine up- fired up great as usual but there was a very loud squeaking which I decided was coming from the distributor using a rubber hose as a stethoscope. The rate of squealing increased with RPM, so I believed it to be mechanical rather than a small vacuum leak which would (I believe?) get quieter with higher RPM.

In any case, I threw new parts at the problem- I replaced the stock distributor (with points replaced with Pertronix Ignitor) with a new distributor from Pertronix.

After dropping the new distributor in the engine does not start. Unfortunately the engine still does not start if I put the original distributor back in.

I'm at the end of my rope here and I'm not sure what else to try. I know all it takes is fuel + air + spark to start an engine but as far as I can tell I have them all. Any tips or ideas would be greatly appreciated!

Here is a list of things I've tried:
  • checked primary & secondary resistance in coil (per Bently, in spec)
  • verified a healthy spark at each of my plugs (by pulling them out and grounding while someone cranks the engine)
  • verified fuel pressure and fuel delivery rate (per Bently, in spec)
  • quadruple checked that my distributor drive gear is correctly aligned and that the distributor rotor points to the number 1 cylinder, TDC when cylinder 1's valves are both closed
  • quadruple checked the order of the spark plugs on the distributor cap
  • statically timed the engine for 7.5* BTDC
  • verified injectors are spraying
  • danced the spark plugs 90, 180, and 270 degrees around the distributor cap
Cheers
Max

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Re: 80 Vanagon Engine no start after new distributor

Post by Amskeptic » Sun Jun 10, 2018 7:30 am

Assuming that you have the original distributor back in, I must ask, did you use grease on the breaker cam to soothe that poor rubbing block from its terrible life? Use high-quality grease sparingly.

Verification Experiment: follow the directions

a) TDC mark at "0" on what you think is #1

b) Have someone rotate engine back and forth across the "0" mark about 20* in each direction. You must verify that # 3 rocker arms are both moving simultaneously. THIS establishes beyond all doubt that #1 is actually on the compression stroke and not the exhaust/intake overlap.

c) Once you have verified #1 is definitely at TDC ready to fire, then check distributor for static timing position and that the #1 is above the rotor followed by 4-3-2- around the cap.

d) Does your distributor have a little white wire on coil (-) 1 that leads into the fuel injection harness? On baywindow buses, that is the fuel injection trigger wire.

e) any stupid dislodging of brake booster line, decel hose, etc?
Colin
BobD - 1978 Bus . . . . . . . . . . .111,130 miles
Chloe - 1970 bus . . . . . . . . . . . 206,787 miles
Naranja - 1977 Westfalia . . . . . 91 414 miles
Pluck - 1973 Squareback . . . . . 55,510 miles
Alexus - 1991 Lexus LS400 . . . 72,113 miles

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Re: 80 Vanagon Engine no start after new distributor

Post by maxsvetlik » Sun Jun 10, 2018 10:37 am

Thanks for the response Colin.

The original distributor had points replaced with Pertronix from the PO, so no grease on the cam there.

a-b) here are the results: ONE of the rocker arms on #3 moves while the crank moves across "0", the other does not move and remains springy (just like the arms on #1)

c) didn't get to this due to a/b

d) It does

e) I've poked around quite a bit in search of disconnected hoses but haven't found any

How do I interpret the results from our experiment?

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Re: 80 Vanagon Engine no start after new distributor

Post by Amskeptic » Tue Jun 12, 2018 8:54 am

maxsvetlik wrote:
Sun Jun 10, 2018 10:37 am
Thanks for the response Colin.

The original distributor had points replaced with Pertronix from the PO, so no grease on the cam there.

a-b) here are the results: ONE of the rocker arms on #3 moves while the crank moves across "0", the other does not move and remains springy (just like the arms on #1)

c) didn't get to this due to a/b

d) It does

e) I've poked around quite a bit in search of disconnected hoses but haven't found any

How do I interpret the results from our experiment?

If you were able to discern movement of #3 intake, then #1 is verifiably at TDC. And the rotor was pointing at the #1 terminal on the cap (when the cap is installed). And the next wire in the clockwise circle is 4 then 3 then 2.

Based on your description, it seems that you have at least #3 exhaust lifter "collapsed". If too many other lifters are also soft and springy, then the engine will have a difficult time starting, but you should hear sounds of combustion and kicks as it is cranking. If your engine is playing dead dead, cranking listlessly, then you need to troubleshoot for spark (easy enough) and fuel. I like to go directly to priming the engine after I have verified spark. I think you have a "wye" where the brake booster attaches to the intake plenum. That wye should have a plastic tube leading to the decel valve. IF you have spark, remove plastic tube/hose from decel valve and carefully pour in a half shot glass quantity of fuel into the plastic tube. Reattach the hose to the decel valve. Attempt to start. Report back. Be careful. If you pour gasoline all over the place, you need to abort and wipe/evaporate the spill, then try again. If the engine bursts into song temporarily until it runs out of the shot of prime gas, it at least will help pump up some lifters. It would also lead us to the fuel injection system/fuel supply. Have you determined that the fuel pump does come on while cranking? It needs to. It gets its signal from the Very Important Little Red/white wire that plugs into the starter spade terminal next to the red/black wire that actually triggers the starter. The little red/white wire goes to the double relay where it activates the pump during cranking only. Then it falls out, and the AFM takes over.
Colin
BobD - 1978 Bus . . . . . . . . . . .111,130 miles
Chloe - 1970 bus . . . . . . . . . . . 206,787 miles
Naranja - 1977 Westfalia . . . . . 91 414 miles
Pluck - 1973 Squareback . . . . . 55,510 miles
Alexus - 1991 Lexus LS400 . . . 72,113 miles

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Re: 80 Vanagon Engine no start after new distributor

Post by maxsvetlik » Wed Jun 13, 2018 5:59 pm

Amskeptic wrote:
Tue Jun 12, 2018 8:54 am

If you were able to discern movement of #3 intake, then #1 is verifiably at TDC. And the rotor was pointing at the #1 terminal on the cap (when the cap is installed). And the next wire in the clockwise circle is 4 then 3 then 2.

Based on your description, it seems that you have at least #3 exhaust lifter "collapsed". If too many other lifters are also soft and springy, then the engine will have a difficult time starting, but you should hear sounds of combustion and kicks as it is cranking. If your engine is playing dead dead, cranking listlessly, then you need to troubleshoot for spark (easy enough) and fuel. I like to go directly to priming the engine after I have verified spark. I think you have a "wye" where the brake booster attaches to the intake plenum. That wye should have a plastic tube leading to the decel valve. IF you have spark, remove plastic tube/hose from decel valve and carefully pour in a half shot glass quantity of fuel into the plastic tube. Reattach the hose to the decel valve. Attempt to start. Report back. Be careful. If you pour gasoline all over the place, you need to abort and wipe/evaporate the spill, then try again. If the engine bursts into song temporarily until it runs out of the shot of prime gas, it at least will help pump up some lifters. It would also lead us to the fuel injection system/fuel supply. Have you determined that the fuel pump does come on while cranking? It needs to. It gets its signal from the Very Important Little Red/white wire that plugs into the starter spade terminal next to the red/black wire that actually triggers the starter. The little red/white wire goes to the double relay where it activates the pump during cranking only. Then it falls out, and the AFM takes over.
Colin
In fact I made an error- while looking for movement on #3 I was actually looking at #4 :pale:
After realizing this, I went back and checked again. With my eyes at the right spot this time, #3 had both valves moving as you described.

I then verified spark plug wire order on the distributor, checked for spark at each plug again as an assistant cranked (they all looked bright and white) and verified static timing. Finally, I dumped half a shotglass of fuel into the intake plenum as described.

Unfortunately the engine did not jump to life, even briefly. I have verified that the fuel is sprayed out of the injectors while the engine is being cranked. This is sufficient information to determine the pump is comes on, yes?

All this makes me think that its a timing issue, but I "know" that the timing is set correctly...

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Re: 80 Vanagon Engine no start after new distributor

Post by Amskeptic » Wed Jun 13, 2018 10:11 pm

maxsvetlik wrote:
Wed Jun 13, 2018 5:59 pm

#3 had both valves moving as you described.

checked for spark at each plug again as an assistant cranked (they all looked bright and white) and verified static timing.
All this makes me think that its a timing issue, but I "know" that the timing is set correctly...
Can you check timing dynamically with a stroboscopic timing light during cranking? Make sure timing light pick-up is on wire for #1 front right cylinder (closest to front of car) and see if mark is anywhere near "0" to 7.5 BTDC during cranking.

If you have been dorking with this problem for a while, may I invite you to clean and gap the plugs to .026". Plugs can develop carbon/oil/fuel paths to ground if there has been a lot of useless cranking.

Also, do you know that you can floor the accelerator during cranking to air out the engine if you have been trying to crank too many times when the cold start valve is triggered (mostly below 55* ambient).

Geesh man, ?? you got spark, you got fuel, what is your battery voltage under starter load? It cannot drop below 10.7 volts or the fuel injection shuts itself off.
??Colin??
BobD - 1978 Bus . . . . . . . . . . .111,130 miles
Chloe - 1970 bus . . . . . . . . . . . 206,787 miles
Naranja - 1977 Westfalia . . . . . 91 414 miles
Pluck - 1973 Squareback . . . . . 55,510 miles
Alexus - 1991 Lexus LS400 . . . 72,113 miles

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Re: 80 Vanagon Engine no start after new distributor

Post by maxsvetlik » Sat Jun 16, 2018 1:09 pm

Amskeptic wrote:
Wed Jun 13, 2018 10:11 pm

Can you check timing dynamically with a stroboscopic timing light during cranking?

Geesh man, ?? you got spark, you got fuel, what is your battery voltage under starter load? It cannot drop below 10.7 volts or the fuel injection shuts itself off.
??Colin??
Timing light reads firing at just before 8 degrees. I guess this fact should eliminate in my mind timing as a contender.

Battery under load is about 13V as I've been keeping it on the charger. However I do recall the voltage across the coil dropping quite a bit lower than 10.7 V last time I checked.

The good news is that we have a new lead! I decided to pull the same two injectors (#3, #4) that I had checked for spray previously. The last time I checked them, I remember thinking they were spraying well enough, but its been so long I'm no longer sure. In any case, neither injector was spraying ANY fuel this time.

So either #3 and #4 injectors are dead, or something is amiss with FI as a whole. In either case, I plan to head back out to troubleshoot when the rain dies down.

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Re: 80 Vanagon Engine no start after new distributor

Post by maxsvetlik » Sat Jun 16, 2018 6:28 pm

The #1 and #2 injectors are also not spraying fuel. I wont be able to test whether the injectors are getting a pulse or the double relay until my assistant is back in town.

I did the Bently "ECU Tests for Fuel Injection" on 24.15. All but one test was in spec. The test that failed was between pins 15 and 10, which has infinite resistance rather than 7 ohms spec. My interpretation of the wiring diagrams is that pin 15 is to the #4 cylinder, 10 sends the batch signal to all injectors

Shot in the dark- is it possible the lack of continuity from the ECU to #4 injector is bringing down the whole FI system?

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Re: 80 Vanagon Engine no start after new distributor

Post by SlowLane » Sat Jun 16, 2018 10:19 pm

The more I read this thread, the more I am convinced that your ECU is not getting a good trigger signal from your ignition.

There have been a number of people here and on TheSamba who have reported poor running issues when combining L-Jet with Pertronix (though none who have claimed that it doesn't run at all, to my knowledge)

Do you have the wherewithal to install points and condenser in your original distributor and install it?
'81 Canadian Westfalia (2.0L, manual), now Californiated

"Wisdom comes from experience. Experience is often a result of lack of wisdom."
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Re: 80 Vanagon Engine no start after new distributor

Post by maxsvetlik » Sun Jun 17, 2018 10:46 am

SlowLane wrote:
Sat Jun 16, 2018 10:19 pm
The more I read this thread, the more I am convinced that your ECU is not getting a good trigger signal from your ignition.
Is trigger signal something I can test with a volt meter / test light? I.e. by taking the ecu harness off and probing terminal 1 and ground?

I'm not opposed to putting in points, I'll have to order them from a web retailer. Pertronix was working fine from after the rebuild till these troubles started, though (about 500 miles)

Another thing I've noticed is that my resistor pack (on the firewall, next to dual relay) is way out of spec. Each resistor reports about 900 ohms vs 6 ohms spec.

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Re: 80 Vanagon Engine no start after new distributor

Post by SlowLane » Mon Jun 18, 2018 6:32 am

maxsvetlik wrote:
Sun Jun 17, 2018 10:46 am
Another thing I've noticed is that my resistor pack (on the firewall, next to dual relay) is way out of spec. Each resistor reports about 900 ohms vs 6 ohms spec.
If so, that would certainly explain the problem you're having, but are you sure that you are measuring the resistors correctly? If a resistor is faulty, it would typically show as an open circuit (infinite resistance). It's fairly rare for one of the resistors to go bad; it would be shockingly bad luck if all four of them have failed.
'81 Canadian Westfalia (2.0L, manual), now Californiated

"Wisdom comes from experience. Experience is often a result of lack of wisdom."
- Terry Pratchett

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Re: 80 Vanagon Engine no start after new distributor

Post by Amskeptic » Mon Jun 18, 2018 9:52 am

maxsvetlik wrote:
Sun Jun 17, 2018 10:46 am
Is trigger signal something I can test with a volt meter / test light? I.e. by taking the ecu harness off and probing terminal 1 and ground?

Each resistor reports about 900 ohms vs 6 ohms spec.

Trigger signal wire from coil #1 to ECU has a dedicated harness joining the main harness within a foot of the ECU plug.
This wire is responsible for triggering the ECU to ground each injector.

The ground path from the ECU "batch fire circuit" to ground is the single wire found at the three-wire-ground party under the intake plenum. These spades MUST not be loose in the slightest on their beautifully clean spade terminals.
Colin
BobD - 1978 Bus . . . . . . . . . . .111,130 miles
Chloe - 1970 bus . . . . . . . . . . . 206,787 miles
Naranja - 1977 Westfalia . . . . . 91 414 miles
Pluck - 1973 Squareback . . . . . 55,510 miles
Alexus - 1991 Lexus LS400 . . . 72,113 miles

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Re: 80 Vanagon Engine no start after new distributor

Post by maxsvetlik » Mon Jun 18, 2018 6:19 pm

With my assistant back in town, I did a few more tests with the test light.

From probing #1 in the ECU it seems I'm getting a strong pulse from the coil. However, it seems the injectors are getting no voltage. Following the trouble shooting page for FI in the Bentley (see attached) the flow chart says I need a new ECU! That is to say, my test light was lit while probing all the terminals specified in "Control Unit has no ground connection".

Colin, I did double check that the spade terminals were clean and well attached to the tree underneath the plenum before I did the above tests.

SlowLane, way to keep me honest. I double checked the resistor pack and they're all within spec :scratch: I don't know what I was doing before. Musta' misread the scale.

At this point its looking like the ECU, though the timing for the ECU to fail is highly suspect. It seems odd for it to fail suddenly after a new distributor. If anyone has any tests that could confirm/deny the ECU, I'm all ears. I'd hate to buy a replacement for it not to be the issue.

Cheers
Max
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Re: 80 Vanagon Engine no start after new distributor

Post by furgo » Tue Jun 19, 2018 8:07 am

maxsvetlik wrote:
Mon Jun 18, 2018 6:19 pm
From probing #1 in the ECU it seems I'm getting a strong pulse from the coil. However, it seems the injectors are getting no voltage.
I'm assuming you tested the injectors for pulses with a test light while cranking

This might be a long shot, but here's one thing that caught me last time I was checking the injectors myself.

If the test light has a 12V bulb, it will flicker very faintly. At some point I thought the injectors were not firing, until I realized that looking very closely, the light was indeed flickering. I seem to remember the A.F.C. manual recommends an LED for this test. A 3.3V LED lightbulb should work for instance.

Alternatively, if you find yourself without a test light, placing a hand on an injector you should feel the clicks as the solenoid opens the nozzle valve while cranking (use a remote starter or an assistant to crank)

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Re: 80 Vanagon Engine no start after new distributor

Post by SlowLane » Tue Jun 19, 2018 9:31 am

I haven't used one myself, but I hear that a "noid" light is a handy tool for troubleshooting injectors.
'81 Canadian Westfalia (2.0L, manual), now Californiated

"Wisdom comes from experience. Experience is often a result of lack of wisdom."
- Terry Pratchett

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