loquinho

To summarize from my previous thread, during a normal drive I had a sudden loss of power with very little pedal response, a single backfire, and a stall. The car would then not start again. I did a round of diagnostics, and determined the following:

Coil has Spark
Plugs have spark
Carb accelerator pump is functioning

After the advice I got here, I suspected timing, so I tore the car down to the timing chain, which had a lot of slack, but wasn't broken, and hadn't jumped a tooth, and put in a new Cloyes heavy duty timing chain, which tightened things up nicely. I put it all back together, and it's still not working - there was very little change. I did a second round of diagnostics:

Fuel pump is pumping gas in spurts like an artery - 8oz of gas in about 4 seconds of cranking the engine.
Fuel filter is clean
No vacuum leaks that I could find

I could get the engine to start up for a few seconds. It was slow and sluggish, and when I tapped the throttle it died. It seemed to improve slightly when I cupped my hand over the carb, but I can't tell if that was my imagination or not. When it's running, there's no knocking or anything, so at least it's not valves, rods, or pistons.

Below is a link to the video I took of one of my tests when it actually ran for a bit. It was one of the vacuum tests, so please excuse the vice grips - it ran just the same without them. I was outside the car taping, so the variations in speed you're hearing are all being done by the engine, not me.


I'm at a loss right now. Anybody have any thoughts as to where I should go next to solve this problem?

SIXFOOTER

So it has spark and it has fuel, but does it get the spark at the right time?
The video link didn't work
Did a cut and paste, check your timing and make sure its right, should be in the neighborhood of 10 or 12* advanced static timing

...Roger...

I agree make sure your timing is right , it sounds as if the timing is retarded.

Did you roll the engine around a few times making sure the timing marks on the gears kept lining up ?

loquinho

I'll check timing tomorrow if I get the chance. I have a light, but I'll need my wife to crank the engine for me.

I didn't roll the engine over a few times before I put everything back together. It seems no matter how much I try to absorb from the forum on the right way to do things, I miss something. Hopefully everything in there is in good shape. What could I discover by having done that?

oldalaskaman

Disconnect the fuel line and attach a hose from the line to a bucket away from your engine. pour known, good gas down the carb inlet and see if it will kick and start, if it does that check your fuel in the tank for water. if you dont have water , pull the sending unit and change the screen at the bottom of it, then change your fuel filter. you may have a blown diaphram in the pump.etc etc. if you didnt change the timeing and it ran and you got the timing chain on right , it should run now
I apoligize for the next question, but does your gas gauge work, and do you have fuel in the tank.

...Roger...

It would just confirm the marks are lined up correctly and not off a tooth.

oldalaskaman

read your other thread, do a compression check

loquinho

I ran the compression test and after a LOT of mistakes, I finally confirmed I have good compression. That thread is here.

My uncle suggested I check the distributor gear, so I pulled the distributor. It looks to be in decent condition, aside from the mechanical advance being gummed up with ancient grease. So, while I had it out, I disassembled it, degreased and cleaned the metal parts, got a small parts kit from Zip to refresh it, and reassembled it with new grease. I also put in a new ignition coil, and new spark plugs, since I managed to break several removing them for the compression test.

I hooked up a brand new timing light to check timing once finished, and the timing light didn't flash. At all. Just to make sure it got power, I ran a jumper cable from the positive terminal of the battery directly to the timing light positive, still no flash.

Based on that, I decided to re-run the ignition diagnostics test once I had everything back together, just in case I messed something up the first time - this time not with my neighbor's help. Results:

Check for spark at plugs: weak and VERY intermittent
Check for spark at coil: weak and very intermittent - I could only get a spark one time in 4 or 5 that I cranked it. I was using a screwdriver across the coil tower grounded to the block.
Connect jumper to positive coil terminal: weak and very intermittent - not battery to coil wiring problem.
Test light (well volt meter in my case) from coil negative to engine block :12V - good

Electrical is really not my thing, and I'm not sure how to deal with almost no spark. I'm wondering if I could have messed something up reassembling the distributor. It seemed really straight forward. When I reinstalled the distributor, I used the rag-plug method in cylinder one to find the beginning of the compression stroke, then brought the engine around by hand to 8* before TDC. I then dropped the distributor in so the rotor was aimed at the #1 plug on the cap.

The annoyance is that without this fixed, I can't really do anything else. I'm assuming the timing light isn't flashing because the current passing through the #1 wire is so weak or non-existent that the inductive pick-up can't close the circuit.

Anyway, so any help or wisdom to share? I'm really unsure how to test anything else to try and isolate the problem. I know it's not the distributor gear, coil, plugs, plug wires, or hot wire to the coil. What am I left with? Points? Condensor? Something else? How do I go about testing any of those?

I just want to drive again.

bluedawg

what do the points look like, whats the dwell set at and can you here the points arc? you didnt say in the first post, but were did the back fire come from. If you pump the accelorator, does it start any easier? Oh and what are the vise grips for? What do the plugs look like? Im assuming stock, what vaccum is it pulling at idle? Not saying i can figure it out, but ill try to help, its been 23 years since i had a points system.

diehrd

I have to agree ,,, points is a good possibility so check em but also I would say replace that coil no testing just grab one and put it in.

bluedawg

Its been so long since ive messed with points, but iirc my old 69 pick up, did about the same thing, turmed out to be points, it seems from description its ignition related, tough to really say with out being there.

LB66383

Put in a new set of points and adjust them. Best if you had a dwell meter, but they're pretty rare nowadays. Then connect the timing light to the coil-to-cap wire and see if you're getting consistent flashing. If so, but no start, replace the rotor. On second thought, replace the rotor just on general principles -- they're cheap.

birdsmith

Loquinho, I've been thinking about this one for awhile now and here's my theory...

FIRST, good on you for completing a PROPER compression test and ignoring my advice to pull the motor. The good news at this point is that your internals are very likely fine, so here's what I think happened-

SOMETHING in the ignition gave up, most likely the condensor but I'm also suspecting the coil. When that happened the car suddenly lost power...it didn't die completely (that's why you were actually able to get it started again) but after a few revolutions of no spark you got a spark and BANG the accumulated gas in the intake ignited and blew out part of the airhorn gasket in your QJet...

You corrected a late-timing issue in your cam, but that wasn't really the problem to begin with. The problem was a very weak spark which was caused by either a dead condensor or coil (the condensor is the first thing I'd change; they're cheap and when they go bad they can make all sorts of wierd manifestations) and it caused an intake explosion that was severe enough to blow out or dislodge the airhorn gasket. The power piston relies on internal vacuum to stay retracted, and without the gasket seal necessary to maintain vacuum it started dumping excess gas into the idle mixture making starting very hard and running very sluggish.

Normal troubleshooting protocol is check for spark/gas/air, not necessarily in that order, but what I think happened here is that an electrical failure caused damage to the fuel circuit, so in one fell swoop you lost two of the three sides of the 'triangle'...

If I'm right the fix could be as cheap as a new condensor and a rebuild kit for the QJet. On a good day QJets are a real PITA to rebuild, and I'm trying to avoid telling you to keep throwing parts at this thing, but I really think that's what happened here- when QJets leak internally they refuse to start and idle properly, and I really think that backfire caused a carburetor problem.

My last bit of advice (unless you're absolutely committed to NCRS accuracy) is to ditch the points ignition and put a Pertronix in there with a Flamethrower coil. I did that with mine not long after I bought it 15 years ago and of all the things I have had issues with the ignition is no longer one of them, it just plain WORKS and I never have to think about it. There are dozens of other guys on these pages that will concur...

Hopefully you get to the bottom of this soon, and keep us posted

centralcalvette

A weak spark will be worthless with compression and fuel. Retest for a weak spark using a spark tester (prefered, non-hei), or a good, new spark plug. Ground it, on good, clean steel, or better yet, a ground wire. Still weak spark ? Set the points to .019" at the highest point of the distributor cam lobe. Good, the points are set (close enough to run). Have someone crank the engine, look at the points, do they arc? They should not. If they do, the condenser is bad. If not, how's the spark? If good (should be by now), try to start it, don't pump the accelerator. Does it sound better, does it start ? If it sounds like it wants to start, mark the distributor (so you can easily set it back), loosen it somewhat, and have someone crank it over while you slowly turn the distributor. It should start now, if the dist is close. If not, relate your findings, and ot will figure it out.

bluedawg

If the points arc isnt that also signs of either the dwell being off(which setting the points might eliminate) or points being bad, id not heard that about the condensor, but it makes sense.it would probably be best to replace the points, set them at .19" like central says, and then listen for the arc/ check for spark, my first vehicle was the only vehicle i had with points, so i dont recall settings but a service manual will know. I remember getting moister in the cap and having to clean it with wd40.

Indiancreek

My first best guess too. I'd pour or squirt fuel through your carb to see if it fires. Hold the choke wide open and crank.

loquinho

Ok guys, sorry for the delay in the response - it took me a little while to find the time to get back out to the shop and get any significant work done.

Per all your advice, I did the following: I sanded down the contact surfaces, got some feeler gauges and checked the dwell on the points. I set it properly to .019". I then checked for spark. I didn't have any at the plugs. I spent the $15 and got a new set of points and condenser. I installed those in the distributor, and set the dwell. I got spark!

the Petronix unit was very tempting, but since I'm using this car to try and learn how these cars work, I'm trying to not replace anything just yet. Now that I know how points and a condenser work, I'll trade out for the Petronix unit as soon as the points give me trouble again, and probably before that. The Ignitor III unit looks crazy simple to install, and the rev limiter is an interesting feature as well.

Now that I knew I had spark, I set up the timing light, which started flashing, so I knew spark-wise I was in business. Unfortunately, when I started cranking the engine, the mark on the harmonic balancer was nowhere to be found. I turned the engine by hand until I was lined up at 8* before TDC. I took off the distributor cap, and realized I somehow had the distributor installed 120* off - the rotor wasn't pointed anywhere towards the #1 plug. I loosened it, pulled it halfway, and got it lined up correctly. Then, before I put the cap back on, I marked the direction of the rotor with some tape on a nearby hose. I put the cap back on, and rotated the distributor so the #1 plug was also in line with that tape. I rechecked the timing with the light, and bingo, I was exactly at 8*.

Unfortunately, the car did not start. So, timing is good, but the car is still not starting. I'm quite certain, due to some other symptoms I discovered, that we're moving on from a timing problem to a carb problem, so I'm going to start up a Diagnostics III thread for that.

Many thanks to everyone that helped me through this process. Even if this wasn't the problem in the first place, I know I fixed several small issues that were probably affecting the performance of the vehicle, which means that when I get it working, it will work better than it ever has, and I'm now not afraid to tear into the engine a little to get things figured out. I love this forum.

bluedawg

Ok so try a little starting fluid. If it starts, then we'll head down a different worm hole.

REELAV8R

You may now have the timing off by 180*. When you discovered it was off by 120* and the timing mark was up it may have been up on the exhaust stroke. Take the dist off again and change it's position by 180*. Then try again nothing will be harmed by doing this. Double and triple check your work make sure you got it right before moving to the carb.

Good job on diagnosing the lack of spark energy and staying focused on that until it was resolved. That is how to fix a problem. One thing at a time and stay with it until it's fixed then if still won't run move on to another system. It's too easy to start throwing parts left and right at things that are not the problem and then getting frustrated because it still won't work. Stay with the ignition system until reslolved completly, you have already determined that is the issue here.