hot spark svda distributor

[TheTominator]

I drove it back and forth to work the past two days, about 6 miles on the freeway at 70 mph and a mile on streets, each way. Smooth starts and running strong. Unless something comes up I should get a chance to time it properly tomorrow.
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"A foolish faith in authority is the worst enemy of truth" Albert Einstein - 1901

If I can't curse, I can't fix it.
71 Bus
78 HD FXS Lowrider 1200cc
An Oldsmobile for crying out loud.

[dweller]

[Randy in Maine]

No dwell to be set.

You do need to re-time the engine correctly after the installation. ONly takes a minute to do it.

Make sure that you keep a spare set of points and a condensor in your tool box or glove compartment.

[dweller]

the air gap has to be set (.035) and then dwell is supposed to be 58*, i had the gap a bit too closed.
I read Ratwell's page on setting the gap.

I'm putting back the old points and making sure it's the new set that are the problem. Then i'll try them again, and send them back if the problem persists.

one question: how much play (up/down) should a dist. shaft have? I didn't have a spring under the dist. when i took it out (left out by mechanic?) and took one from a spare engine and installed. Still a slight amount of play in the shaft up/down. When i compress the shaft the spring returns it up, but then there's a bit more 'up' that i can lift it. The dist. seems to stay seated in the slot regardless. No other play (side to side) detected.
dp
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77 Westie 2.0L FI ... slowly restoring bit by bit...

[Randy in Maine]

Try timing it first.

[dweller]

[Randy in Maine]

You are doing OK dweller.

This is going to be kind of a long reply, but I am not talking down to you. You are doing a great job of logically ruling out components and thinking about how the whole thing works. that is exactly the way to figure it out IMO.

I don't have one of those "hot spark" points replacement modules (I have a compufire) but when you use one of those, the dwell angle is usually preset to about 58º from the factory and that is OK. You do need to make sure that the internal resistance of the coil meets the impedence requirments of the points replacement module or it will soon burn up. I don't know what those numbers are but it should be with the instructions they sent you with it.

Anytime you dink with the points or install a module, you need to adjust the timing as they pick up the "fire" signal from a different point on the distributor. If you think that the jerking you are getting is from the module, just put your points/condensor back in and readjust accordingly.

Here is how I adjust any distributor with a centrifical advance component:

Remove the vacuum advance hose from the vacuum can on the distributor. Loosen the clamp that holds the distributor tight. Hook up the timing light. Fire it up. All of the centrifical advance should be in by 3000-3500 RPMs and we want to set that "all in" point to about 28º in a bus. I like to rev it up and down a few times as I watch the timing light to make sure that it is smoothly advancing and retarding and that the light does not "scatter" too much. Set that to 28º and tighten down the clamp with your 10mm wrench. I always shut the car off to do that and let the initial idle land where it wants to. Nobody drive at idle anyway, but I like to set the idle speed at this point.

Then reattach the vacuum hose conection to the distributor can and again wind it up to about 3500 RPMs. Back off the throttle to about 1/3 and allow the vacuum function of the distribututor to deliver its maximum advance since the ported vacuum will increase with the deminished throttle. We need to make sure that the total advance from both centrifical advance (28º) and the total advance from the vacuum advance (about 12º) does not exceed a total 42º.

From ratwell....

Here is a chart for your 205S or 205P distributor (they are just about the same)

A couple of more things...the distributor vacuum can should be able to hold a vacuum induced on it from a hand vacuum pump as should the EEC valve in the air cleaner that is plugged into the ported vacuum from the thottle body to the distributor. Sometimes the seals go bad and they leak vacuum. Also other common vacuum leaks are at the power brake booster check valve, the big S boot from the AFM to the throttle body, the decel valve, the Y shaped boot that powers up the brake booster/decel valve/air plenum, and the aux air regulator both at the 90º boot at the bottom and where it ties into the S boot. Look at them, test them, adn secure them with corks, duct tape, electrical tape, "wire ties", Gum Out spray or a vacuum hand pump or what ever it takes to make sure they leak no engine vacuum. Also make sure that the electrical connections at the starter are clean and tight, the double relay is clean, tight and grounded, and that the vacuum line going to the fuel pressure regulator is perfect.

While you can make a Cold Start Valve gasket from "scratch" a better option might be to take that CSV to a parts store and see if they can find a EGR valve gasket to fit it. I want to say a 87 Buick witha V6 would be a good place to start looking. Use some gasket cement from Permatex to hold it on the air plenum side. Wheel bearing grease on the CSV side. That lower CSV screw is a bear to get in and out of there and I use a screw driver like this to do it.
http://www.sears.com/shc/s/p_10153_12605_009474760...rewdrivers

Finally, test the output of the Temp Sensor II with your ohm meter and compare it cold and hot with the readings from http://www.ratwell.com/technical/TempSensorII.html

The mechanical connection at the head and the electrical connection into the wiring harness need to be clean and tight.

Sometimes there gets to be a dust layer inside the AFM unit and it needs to be cleaned with an electrical contact cleaner and sometimes if the magnetic strip gets scratched or worn out it will hit a dead spot and cause a similar jerk.

Some additional photos...

[dweller]

Thanks Randy, that worked. I loosened the dist. clamp, and moved the dist slightly to check it it was adjustable, took off the hose and cranked it, and it set at 28* at around 3-3500rpms. Didn't have to move the dist again, as i guess i bumped it there at onset. Cut it off and tightened the clamp.

Then, checked the timing and it was ~4*, but the idle was too low. Brought it back to ~900+/-, and it set on 7.5*.
Ran it back up to 3-3500rpm and it was at 36*, backed it off to 1/3rd throttle, and it sets about 28-32* . (guessing at the 1/3 throttle mark...)

Does this sound about right?

will start looking for the vacumn leak tomorrow along w/ the brake work.
Btw, i purchased that multimeter you rec'd in another thread.
Both my tach/dwells read different settings for the same engine, enough to make me doubt them both. So, when it arrives will recheck it all.

Will test drive again tonite to work and around a bit to see how it runs.

thanks again, enjoy reading your advice.
dp
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77 Westie 2.0L FI ... slowly restoring bit by bit...

[Randy in Maine]

[dweller]

okay, i'll go through it again, for what i thought was right before, wasn't.
Took the bus to work tonite, and didn't make it 2 miles before BAM...BAM...BAMBAM..BAM. Like a one armed Thor coming from the engine, same as the night before, but way worse. I was doing about 45mph and the engine was bucking HARD constantly. Pulled to a stop and turnaround and coaxed/coasted back home with it. Coasted literally, b/c it would do the BAM/buck at any speed. I'd get a bit of speed up and coast keeping the engine from cutting off, w/ clutch in, till i needed some juice to move some more, buck along and coasted the few miles home. Parked it.

I'll run through the procedure again, and test drive once more, but after that if no improvements will be sending the Hot Spark set back to see if i can get that magic 'second set' others have found to work. Otherwise will try to get my $$ back and invest in a different brand, or use the conventional point/condenser setup.

The 'bucking' is pretty harsh, and i don't want to put this engine through it much more. If it's another problem (other than the new breakerless) it should occur also w/ conventional points. And it hadn't before the new point setup and my fiddling w/ it. So i'll probably try using the old points again to check it out.

I'll deal w/ this over the next 2 days i have off and see what i can find out.
And follow your instructions above w/ the latest details.

The vacumn leak sounds like it is coming from the CSV. I used a clean piece of tubing i had (about 2+ feet leftover from some i used to hook up the charcoal canister and fan housing). Put one end in my good ear outside the eng. compartment, and the other i searched for the source. It's coming from the CSV w/out a doubt. I can hear it w/out the tinhorn tube, but really well w/ the tube since it blocks out any other sounds. So the gasket will be replaced w/ one i make first, and i'll see if i can find the Buick gasket if need be. From what i can tell, the gasket on it now has a dimple in on one side, i think i can detect a bit of space there too, hard to tell, black on black etc.

thanks again for your help. Will update over the next few days.
dp
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77 Westie 2.0L FI ... slowly restoring bit by bit...

[Randy in Maine]

The "bucking" is most likely coming from a poorly connected temp sensor II or a a scratched/worn spot on the AFM or something else causing it to run lean like that.

After you get this figured out, it would be worth it to have the engine /FI combo dialed in with an exhaust gas analyzer.

[dweller]

quick question as i work on some hoses: you said

"A couple of more things...the distributor vacuum can should be able to hold a vacuum induced on it from a hand vacuum pump as should the EEC valve in the air cleaner that is plugged into the ported vacuum from the thottle body to the distributor. Sometimes the seals go bad and they leak vacuum. "

i have one hose running from dist.vac can to throttle body. the EEC appears to be hoseless on a small nipple . I have a T i can put in line, but are you saying it should also be in the line that goes from dist.vac. can to throttle body?

I have a larger hose running from EEC to charcoal canister, on that same EEC there is a small nipple coming from the face of the EEC, no hose.

looking at this pic: http://www.ratwell.com/technical/VacuumHoses/VacuumHoses1.jpg

directly behind L (the nipple is hidden) line K goes to dist.... line M goes from vac can to throttle body. I can just Tee line K into M?

next will be looking at the hard lines from evaporative system (that run up into the wheel wells, air intakes on sides, and come into the top of the engine compartment. One side (passenger) small hose leads to the charcoal canister, the other is just open w/ no hose. Can i T those together to the charcoal canister?

i've put a new gasket behind the CSV, but haven't cranked yet to test. Will after getting the hoses all connected.

thanks.
dp
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77 Westie 2.0L FI ... slowly restoring bit by bit...

[dweller]

[dweller]

falling headfirst into the "what where you fucking thinking?" catagory, my bus's PO or his POS mechanic decided to instead of paying $2.00 for a pin, and .95cents for a c-clip, decided to weld the pin onto the handbrake cable lever. Must have been the last pair of shoes he'd ever needed.

When i first saw it, i couldn't tell what it was holding the pin in, and then when i got the shoe off, prayed it was solder.... nope, welded. 45 minutes of cutting w/ my dremel finally cut off the offending blob to free the lever from the old shoe. Now will have to wait the week for the replacement parts from BD to finish a brake job. I ordered a pair...

any guess what i'll find on the other side's brakes?

on edit: yep, on the other side too... what an idiot...

dp
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77 Westie 2.0L FI ... slowly restoring bit by bit...

[TristanM]

Dweller,

FWIW, I used the Hot-Spark kit with my SVDA in a 1600 and it ran fine for about 50 miles before the symptoms you described started happening. The owner of H.S. suggested using a ballast resistor....I wondered why I would need another ballast resistor if my coil had the correct impedence? Plain and simply put, the problem progressed until I switched back to points and condenser....no more problems. Why doesn't Compu-Fire or Pertronix suggest to use a thermal paste and ballast resistor in their instructions?....Most likely because they are a better product. Just my .02.

[aryue]

That weld sounds like it was the work of the DPO's mechanic trying to flat rate the job.
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OldandSlow - but still chuggin.
http://www.ph.utexas.edu/~yue/VW/VWBus.html

[dweller]

[dweller]

[mikedjames]

Over here in the UK we also get Accuspark brand. Basically a Pertronix clone but with thermal paste under the module . I have run both Petronix (until idiot wire swap) and then Accuspark which is half the price.
Both of these work well with a Bosch stock coil and with no condensor.

The misfire and bucking could be breakdown of the coil due to the higher spark voltage with the electronic module, or a fault in the ignition sensor in the distributor.

The rubber grommet with the ignition module is to protect the wires going through the hole in the side of the distributor. Need to make sure the wires inside the distributor have a big enough loop in them to allow the vacuum advance to operate smoothly without pulling on the wires.

THe great thing with the Accuspark was it has 'adaptive dwell' which means that at low RPM the dwell is less than 45 degrees as it does not need to spend that long loading up the energy in the field on the coil primary (once the current maxes out with the points closed, the remainder of the dwell time is heating the coil) and it then maxes out at 40-50 degrees at higher RPM. And when the engine stops, the current cuts. So no more hot coils, and the module doesnt need to dump as much heat.
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1974 VW T2 : Devon Eurovette camper with 1641 DP T1 engine, Progressive carb, full flow oil cooler, EDIS crank timed ignition.
Engine 1: 40k miles (rocker shaft clip fell off), Engine 2: 30k miles (rebuild, dropped valve). Engine 3: a JK Preservation Parts "new" engine, aluminium case: 26k miles: new top end.
Gearbox rebuild 2021 by Bears.

1979 Westerly GK24 24 foot racer/cruiser yacht Forethought of Gosport.
1973 wooden Pacer sailing dinghy

[donzi33z]

Bought a hot spark It worked well for a few months It started dying out when the engine got hot. I have emailed the guy for a replacement. He tried to tell me I had too much voltage going to it. Performed the voltage /ohm tests and it was within specs. Wound up buying the EMPI drop in distributor The fit was a little tight but it runs very well with no further issue. I do not recommend this product

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