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Volkswagen Rabbit, Jetta, Scirocco, Convertible: 1975-1984 (A1) timing marks


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Last Post: May 1, 2014 5:26 PM Last Post By: tcovenant2000
buguy1

Posts: 7
Registered: 04/13/14
timing marks
Posted: Apr 15, 2014 7:56 AM
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Here is the start of a long post. Bought an 84 Rabbit for my son and many issues trying to get it on the road. Fuel, Lambda are all for future posts. I'm sure all this ties together but I must start somewhere.It's actually 84.5 w/ donut spare, two fuel pumps, etc. Manual trans w/ AC.
First issue is with timing. Crank set to TDC according to flywheel marks. Dist set properly. Cam sprocket has me befuddled.On the outside(away from engine) is the dimple and on the inside there is a hash mark. Thought maybe someone had put the pulley on backwards but looking at another 84 cam it is the same way.Coincidence? Motor is 1.8 and I believe it's a JH code. I have tried setting timing using both of these marks and neither wa sa success. Reverting to my shade tree days ,I checked the lobe position on #1 cyl. When using either mark valves are not positioned correctly. I turned the cam to have both #1 valves closed and the car fires(briefly, but thats another post) and sounds fine. Any ideas? I'd like to think I'm missing something really basic. I'm new to this site and the world of water cooled. I spent many years rebuilding, maintaining air cooled. These things are a slightly different animal. Any input is greatly appreciated.
tcovenant2000

Posts: 1,763
Registered: 12/09/03
Re: timing marks
Posted: Apr 15, 2014 5:51 PM   in response to: buguy1 in response to: buguy1
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Was the car running when you bought it?
My '84.5 has a dimple facing away from the engine and a hash mark facing the engine. Neither of these are correct. There is a dimple on mine facing toward the engine as well. It sounds as though your crank may be at TDC, but your disty may be 180 out from the cam. Try turning the crank 180 and see if the cam now lines up, but the disty is pointing the wrong way.
Another, better way is to use the pulley marks on the crank and intermediate shaft to ensure they are aligned together.
The disty is really the only one that can be put on incorrectly, generally speaking. If the car wasn't running and was in unknown state, it's possible someone has the disty 180 out from the crank.
It's also possible the flywheel was put on incorrectly. Pull the #1 plug. Put a soda straw into the hole and watch the soda straw as you turn the crank. Does TDC on the soda straw line up with the crank TDC as viewed from the trans hole? Does TDC on the crank pulley line up at 12:00 when the trans hole shows TDC?

Thomas
buguy1

Posts: 7
Registered: 04/13/14
Re: timing marks
Posted: Apr 16, 2014 4:09 PM   in response to: tcovenant2000 in response to: tcovenant2000
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Thank you for the response.
The car wa snot running when we got it, however it was "in need of a fuel dist". Got it started with 2+2 and it would idle and run until put under load and then would starve for fuel. Transfer fuel pump had siezed and apparantly blown fuses. PO then direct wired the in line fuel pump to a toggle sw on the dash. Both fuel pumps have been replaced new fuel pump relay and wired to spec. Good? Nott so good.
Anyway the point of all that was I did see the car run decently. Next dilema, #4 spark plug hole was hogged out beyond heli coil or time sert repair. Oversized, mismatched plug was forced in and siliconed! First time I ever saw that. Found that while doing a comp test. By the way comp was good and even 1,2,&3. Bought a head from a running Scirroco. Bolted it on, new head gasket,etc. That's when I ran into the timing mark issue.
I am going to try the things you mentioned today and see what I can figure out. Once I'm satisfied with the timing issue, I can move on to fuel.

By the way, any idea of why there are "incorrect " timing marks on cam pulley?
Thanks again.
Steve

tcovenant2000

Posts: 1,763
Registered: 12/09/03
Re: timing marks
Posted: Apr 16, 2014 6:14 PM   in response to: buguy1 in response to: buguy1
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So the head is from a 'rocco? As is the cam and cam gear, I assume? That's maybe what's wrong. I think the markings are different.
Nevertheless...I still think you ought to use the crank pulley and intermediate shaft pulley to line this puppy up. If you get the crank to TDC and you get the valves closed on #1 and you get the disty pointing to TDC you should be good to go.

Thomas
buguy1

Posts: 7
Registered: 04/13/14
Re: timing marks
Posted: Apr 17, 2014 5:26 AM   in response to: tcovenant2000 in response to: tcovenant2000
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cam, gear and head from 'rocco. Cam . gear and head part numbers all match what I took out of the car. The cam marks are the same on both cams. I can only assume it was the original motor .
Used a straw, good eyes and common mechanical sence and can get the car to fire. Breifly. Which leads to my next problem.
On my way to work soon so keeping it breif. I have no voltage to the frequency valve when the fuel pump relay is jumpered 30-87. Pumps run, good measured system pressure. Good spray at all injectors which increases whe I lift the ars sensor plate. Car will run a couple seconds then die. Starts immediatly and dies. so on and ao on. Tested Lambda relay and to the best of my skills it tests OK. Cleaned fuel dist,freed plunger,etc. Will the lack of a working freq valve cause this behavior? Also, no cont in the thermo/time switch when cold.
Thanks in advance
Steve
tcovenant2000

Posts: 1,763
Registered: 12/09/03
Re: timing marks
Posted: Apr 17, 2014 5:25 PM   in response to: buguy1 in response to: buguy1
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100% yes. Timing isn't your issue. If the frequency valve isn't running with Key On and FPR jumped out you've found your problem.

The Freq valve, along with the lambda controller and other things are powered from the Power Supply Relay which is located in the spaghetti under the steering wheel.

However:
The Freq Valve, the Lambda controller, the heaters for the CPR and the Aux air regulator are all grounded at the 5th valve on the manifold. There are three brown wires that should be connected to one of the mounting bolts on the 5th injector. Check those first.

Thomas
buguy1

Posts: 7
Registered: 04/13/14
Re: timing marks
Posted: Apr 17, 2014 7:30 PM   in response to: tcovenant2000 in response to: tcovenant2000
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OK. Replaced the Lambda(02) relay today. Also, Cleaned grounds at the csv. Terminal 1 of the hall sender was ugly so I cleaned that also. I now have a buzzing Fv, power to the CPR and the CSV. Same result. Car starts and then dies. I can start it with some throttle and it will run the same length of time. at higher RPM About 3- sec.
I have replaced both fuel pumps, accumulator, filter, cleaned the fuel dist, cleaned the CPR screen and have 70= PSI as system pressure. Actually here is what I get. With fpr jumped 70+ psi. When attempting to start, I get the 70 psi for the breif period when the system primes 2-3 sec and then back to about 30-35 psi.(It will hold that pressure almost forever) When I turn the key system pressure is back to 70 when cranking. I've not checked cold control pressure yet . Still looking for the correct fitting to make the complete unit.
Also attached my dwell meter to the test port . Not that I know what I'm looking for , but looking for something. With key off I get nothing on dwell, cranking the motor I get nothing, and when it starts I get nothing. Proven good dwell, tach voltage meter. Haven't found much info on that subject with a non running motor. Feel free to direct me.
Checked al vac lines,grounds , etc.
I know I'm missing something just not sure where to find it.
I also want to thank you for your input. I suspect thes posts are all over the place as far as subject goes. I spend alot of time searching, reading and asking. Looking forward to driving this little critter down the road.
Thanks in advance
Steve
tcovenant2000

Posts: 1,763
Registered: 12/09/03
Re: timing marks
Posted: Apr 18, 2014 5:47 PM   in response to: buguy1 in response to: buguy1
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You're close.
What you're missing is almost certainly the coil signal to the fuel pump relay. I see where you jumped the relay out and got 70+ but you didn't say if you tried to start it that way. I notice, also, that you are getting the 70PSi during the 3 seconds of priming.and when cranking. Does the tach move while you are cranking? If no, then the coil wire signal isn't getting to the underdash (cluster and relay). If the tach is moving it doesn't mean that you have a coil signal to the relay.
With the relay in, the relay doesn't need a coil signal during priming (3 secs or so) but it does need it after, so having 70+ for the prime time is correct. No coil signal would shut off the pumps. If you are cranking, fuel is flowing but the injectors won't open below about 40PSI, so holding at the 30-35 for hours is correct and a good sign.
I don't like that you have no dwell signal. One of those two wires goes straight to ground at the cold start relay. Ohm it to bare metal on engine. Should be 0 ohms. The other wire comes from the Lambda controller. It's the same signal as goes to the freq valve. If the valve is humming you should have a dwell signal there.
Try this:
Jump FPR. Does it start and run? Or just die after the 2-3 seconds? Once you have the right fitting you can open the valve on your jig and run the engine while monitoring fuel pressure. What happens to fuel pressure while you are running?
You may need to pull the injectors and check for good spray. The prime time also includes an injection of fuel into the manifold from the cold start valve. If one or more injectors isn't working or if they arent' getting fuel (bad fuel disty) then it will start and run for 3 secs or so. But, not after the three secs. Another thing you can do is wire the cold start valve to the battery (use a fuse and a switch! Fuse to protect you from fire and switch so you can shut it off when you aren't cranking). If the cars runs longer (even crappy running) then you've got fuel flow problems somewhere.

I don't mind helping. I've been working on these things for years! I love my Wabbit! Had it for 12+ years now and very, very happy! Weather is getting nice. Time to un-winter it and drop the top!

Thomas
buguy1

Posts: 7
Registered: 04/13/14
Re: timing marks
Posted: Apr 19, 2014 7:43 AM   in response to: tcovenant2000 in response to: tcovenant2000
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and getting closer. Cleaned all coil terminals. Jumped the fpr and lo and behold it fired and stayed running@ 1500-2000 rpm with my foot on the throttle. Still dies at idle. I put the fpr relay in and got the same results. Very exciting. Sounds decent when running a littlt miss here and there but overall sounds good.
I ohmed the test port to ground and got 1 ohm. Also noticed the wire at the top of the 02 sensor is sort of crushed or bent over wire, connection is still there but i am not very trusting of the condition of the sensor.Still no dwell signal when cranking or running. I have another 02 sensor and I am really looking forward to changing it.
What is the 1 ohm reading telling me and can I test the replacement sensor before installation as it is not new.
what to do about the idle or will the new 02 have an effect on it.
Again, thank you.
tcovenant2000

Posts: 1,763
Registered: 12/09/03
Re: timing marks
Posted: Apr 19, 2014 12:59 PM   in response to: buguy1 in response to: buguy1
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Yay! Coil wire was it!
Very good signs that she runs.We can fix the dies at idle, but need to look elsewhere first.
A broken O2 will send a "Too Lean!" signal but is SUPPOSED to be ignored. However, the Lambda TEMP switch may be bad.
When the lambda temp switch is closed (cold engine) it tells the controller to ignore the O2 sensor and sets the Freq Valve to 60% duty cycle (higher is richer). So we need to verify that. On your 84.5 it's attached to the head coolant inlet. Follow upper rad hose to the head. There's a bunch of sensors there. The one you want may be on top or below. It's easy to spot, as it has two wires and both wires have a separate connector. The other sensors will have multiple wires on the same connector. So: Find it. Pull both wires off. After car sits overnight, ohm across the sensor. Should be 0 ohms or close to that. If not, sensor is bad. No worries. Get a paperclip and unbend it. Push it into the two wires and then tape it with electrical tape so it can't touch anything. Next trick is to start the car. Does it run better? Idle? It should be noticeably better. You can leave it like this for the duration of the testing, but don't try driving around with it jumpered. It's only supposed to be 0 ohms when cold. It will overrich and cause crappy running and damage to Cat converter.
If the O2 is suspect, simply disconnect it. It only affects warm operation (assuming the lambda temp sensor is good). Disconnecting it will prevent it from affecting operation.
Back to the test port. Yes. One ohm on the brown wire to ground is fine. Keep in mind that you only see a signal at the test port when the engine is running or you jump the FPR (freq valve is humming).
Try putting the meter on AC VOLTS. Connect to the lambda test port. Run the engine and see if you get ANYTHING. It's basically a 12V square wave, so the meter on AC VOLTS should read somewhere between about 3 and 10V. I don't have a wiring diagram handy, so can't remember if it's supposed to be the same wire as the freq valve or a different one.

I await further results!
Thomas
tcovenant2000

Posts: 1,763
Registered: 12/09/03
Re: timing marks
Posted: Apr 19, 2014 1:00 PM   in response to: tcovenant2000 in response to: tcovenant2000
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Oh...no...there's really no way to test an O2 sensor without installing it and running the car until hot and then checking freq valve.

Thomas
buguy1

Posts: 7
Registered: 04/13/14
Re: timing marks
Posted: Apr 23, 2014 4:56 AM   in response to: tcovenant2000 in response to: tcovenant2000
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OK, here we go. Where to start. I get no ohm reading at the temp control. After running the car till hot, still no reading. Jumped the two wires leading to it and no real change in running. I can keep it running at about 1500 rpm. I was able to get a dwell reading. At 1500 +- I get around 40 on an 8 cyl scale. Increases as I increase throttle. we're getting closer.
Just to add to the mix,as I was looking around, there is a green & blacck wire that comes from the "harness tha goes to the cpr. Two to the cpr but cant find a home for the third.
The o2 light goes on at about 2000 rpm and goes back off below that.
The car starts easily , still has a miss but I feel were making good progress. I decided to take a couple days away from it. Dont want frustration to set in. Again, thanks in advance.
Steve
tcovenant2000

Posts: 1,763
Registered: 12/09/03
Re: timing marks
Posted: Apr 23, 2014 11:01 PM   in response to: buguy1 in response to: buguy1
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I am 600 miles from the car, so can't help, really with the wiring. I can take a look at that CPR harness when I get home Friday. On a guess I'd say it's oil pressure or temp sender for the temp gauge. But I will have to look.
Dwell of 40 on 8 Cyl? Don't know what that means, as I've never tried it on an 8CYL scale. I think the scale is different for 4 cyl? 1/2? Need to know. If it's reading 40 on 8 cyl and that means 20 on 4 cyl then that's not so good and likely why the car dies. Also, if it is reading 40 on 8 cyl and that means 80 on 4 cyl that's also not so good and likely why the car dies. It's somewhat of a good sign that it goes up when RPM's go up, even though it really shouldn't. Likely means that injector sprays are bad so it's starting to starve for gas.
The Lambda temp sensor being "open" (infinite ohms) when cold means it is bad.
Next tests:
1. Let it sit overnight. Disconnect the O2 sensor. This is in prep for a later step.
2. After sitting overnight, jump the two Lambda Temp wires with a paperclip and start it. Does it run better? Easier to keep idling? Jumping the Lamda temp sensor is only meaningful when engine is cold. If warm, it makes things worse. Hook up the dwell meter. It should read 55-60% (which is 50-55 degrees) with the lambda temp sensor wires jumped together. If it doesn't, something more fundamental is wrong. Unlikely but possible.
3. Keep it idling for 2-3 mins, then let it die. Unjump the Lambda sensor. Start it again and what is the dwell? With Lambda unjumped and O2 disconnected it should be spot on 50% duty cycle (45 degrees of dwell). How does the car run now? Better or worse than step 2?
4. Keeping it idling, with the engine still warm, carefully grab the wire that connects to the O2 sensor (not the end that actually is attached to the O2 sensor, the other end...that disappears into a harness) and hold it against bare metal (ground somewhere...maybe use a jumper wire to - on battery). This simulates a REALLY LEAN signal from the o2 sensor and dwell should start to climb. Does car get easier to keep running or harder? This will tell us if she's too rich or too lean.

Are you SURE the O2 light comes on above 2000RPM and off below 2000? Do you mean the oil light? That would make more sense...especially since your mystery wire might very well be the low-end oil pressure sensor which, when disconnected, will make the oil light come on (and usually a buzzer) when above 2000RPM. The O2 light is on a counter, which is tied to the Alternator light and should have nothing to do with RPM's.

Thomas
buguy1

Posts: 7
Registered: 04/13/14
Re: timing marks
Posted: Apr 29, 2014 8:03 PM   in response to: tcovenant2000 in response to: tcovenant2000
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OK. More test results. I'm basing this on the fact that my dwell meter values are to be doubled for a 4 cyl engine as it only has an 8 cyl scale. All the info I can gather tells me to doublu values. Seems to hold true for RPM so I asm *** uming it is correct for dwel.
With Lambda temp wires jumped(cold motor) dwell is 70 deg. Holds steady at that.
Motor warm, temp sensor wires not jumped or connected dwell is 50 deg
Grounding the o2 sensor inreases dwell and seems to run a little smoother. I can almost
maintain a 950 RPM idle. Getting closer?
What' your diagnoses , doctor.
Thanks in advance
~steve
tcovenant2000

Posts: 1,763
Registered: 12/09/03
Re: timing marks
Posted: May 1, 2014 5:26 PM   in response to: buguy1 in response to: buguy1
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I'm liking it more. 70 degrees with lambda jumped is really high...works out to 77% duty cycle and the things only good up to 80 or 85...but with O2 disconnected you're hitting 50 actual, which works out to 55%, which is 10% high, so your 70 is probably 10% high also meaning more like 63 actual dwell, which works out to 57% which is right where I want it to be with lambda jumped. So, yeah. I'm liking it.
Grounding O2 makes it smoother and increases dwell. That's good and bad. Good that it goes up, bad that it runs smoother when doing so. It's starving for fuel, which is what I expected...why it won't idle well. Or else vacuum leaks. Also, tells me the O2 is likely bad...because it should be compensating.

Next step is to connect the O2 sensor and warm it up and watch the dwell. Make sure the temp indicator is showing mid-range or the O2 won't be warm enough to read correctly. What does the dwell read when idling with O2 connected? Hopefully really high...which still indicates a lean condition but also a good O2.

For the lean condition you're looking at bad injector sprays and/or vacuum leaks. I'd start with injector sprays, since it's hard to idle.
Oh...one other thing...with the engine cold and off (so you don't burn yourself), locate the idle screw (it's a hex head screw sticking out of the throttle body (where the air intake meets the manifold). It points toward the firewall...kind of hard to see. Can you turn it easily by hand? If you can then you have a big vacuum leak right there. You'll want to back it out (count how many turns) and go to a hardware store and buy replacement orings then put it back in the same number of turns.

Thomas

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