Engine won't reach 2000 RPMs under load

[Spittybug]

If your micro switch at the throttle is functional, then it will have cut the vacuum to your distributor and your 13* is accurate. If the switch wasn't working, you'd have seen >23* I would guess. What I would have like to have seen is you rev the engine and confirm that the timing advanced! For that you SHOULD disconnect the vacuum advance so that it doesn't interfere with making sure that any advance is purely centrifugal. I'm theorizing this because if for some reason you aren't advancing as the RPMs go up, the spark comes late in the stroke and you are basically igniting the charge the piston is nearing the end of its throw rather than closer to TDC. If too much unburned charge leaves the cylinder, that's when you can get the popping in the exhaust.

[jangell]

Ah, I see. Ok, I'll put a few things back together and test that on Thursday morning. Thanks!

-- Joe

[Ron]

If your micro switch at the throttle is functional, then it will have cut the vacuum to your distributor and your 13* is accurate. If the switch wasn't working, you'd have seen >23* I would guess. What I would have like to have seen is you rev the engine and confirm that the timing advanced! For that you SHOULD disconnect the vacuum advance so that it doesn't interfere with making sure that any advance is purely centrifugal. I'm theorizing this because if for some reason you aren't advancing as the RPMs go up, the spark comes late in the stroke and you are basically igniting the charge the piston is nearing the end of its throw rather than closer to TDC. If too much unburned charge leaves the cylinder, that's when you can get the popping in the exhaust.

Since it was cold, the thermal vacuum switch should be directing the vacuum to the WUR/CPR, so the switch would have no effect. IE the vacuum advance should have been disabled (but not for long). Good thing is that the setting is probably correct.

===========

P.S. If the RPM drops when pulling each wire, there is no need to check the cap and rotor (or if the wires are in the correct order ;-), they are doing their job.
If you are going to tear it down that far, you might as well change them both while you are in there...

[jangell]

Didn't manage to test the distributor today, unfortunately: I put back the bits I'd started removing the other day (mostly the W pipe and a fuel injector), and tried to start the car. It cranks fine, and would fire for a fraction of a second (sounded like up to three cylinders had fired before it just went back to cranking), and then it would just crank and crank. If I paused for 10 or 15 seconds it would fire once or twice and then go back to cranking.

I confirmed spark with a timing light, and I'm pretty sure I had fuel as I could smell it (I didn't pull any lines to confirm, but the fact that if I let the car sit for a bit before cranking would result in the car catching very briefly implies to me that I have fuel). I tried putting the CPR plug on the cold start valve, but it still wouldn't start. I pulled the cold start valve and put it in a jar, cranked the engine, and the jar was dry. I tested the cold start valve with a PowerProbe by applying 12v to one pin and ground to the other with the RPM relay jumped; again, nothing, no matter which pin I put 12v to. I didn't feel a solenoid kick when I applied power, but I'm not sure if the valve is strong enough to feel it.

I'm thinking that either the cold start valve is dead, or it's plugged and not operable. I suppose I'll order another one (and a cap and rotor, while I'm at it) -- unless anyone knows how to clean it and get it running again? This is most annoying, since I want to do EFI this fall, and I don't want to replace a part that I'm not going to use in a few months.

I tried to use a multimeter to test the harness connection to the CSV, but I was unable to get a reading with my multimeter. Some searches suggest that it is very difficult to get a reading from it for some reason. At the moment I'm assuming my thermotime switch is good, and that it's the valve that's bad.

I've attached a few (admittedly poor quality) pictures of the CSV's outlet. It looks 'dirty', but I don't know if that's how it's supposed to look. While the hole in the center is clear, it could be plugged up inside the housing.

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Again, thanks everyone for your help. I'm going to clean the tank and replace the fuel pump on Sunday, put in the Bosch plugs I ordered and probably check out the cap and rotor, since I can't actually start the car right now.

-- Joe

[lazabby]

You might check the wiring (plug) going to the CSV. I had a situation once where one of the wires in the plug was not seating properly so it wasn't making the connection.

[jangell]

I don't think ti's the connector on the harness. I should mention that this is a new harness (about a year old). Still, I should have tested it.

This morning I did do a few more tests suggested by Dave Swingle, since it's pretty uncommon for these to fail. Here's the list in case anyone else needs it:

1 – take the cold start valve off the engine.
2 – plug the grey plug from the warmup regulator onto the cold start valve. Put the cold start valve in a cup or jar.
3 – Pull the RPM relay. Jumper the brown wire on that socket to the Yellow-red wire AND the white-purple wire (the fan fail jumper is good for this if you have one). This will turn on the fuel pump AND hotwire the cold start valve at the same time.
4 – See if this makes the Cold Start valve spray. If so, it is not bad and you are chasing other problems. If it does not spray:
4A – Take the line off the cold start valve and turn the fuel pump on again. If no fuel comes out of that line, the pump isn’t running and you are chasing other issues. If fuel comes out of that line you probably do have a bad cold start valve.

ALSO - disconnect the cold start valve and measure the contacts on the valve with an ohm meter. If you read just about anything but infinity it’s good. Should be under 200 ohms.

ALSO – see if you can start and run the car on brake cleaner sprayed into the intake. If it will run on this, the entire ignition is good.

ALSO - take off the air cleaner. Have an assistant try to start the car. While cranking press the air flap with your finger. This will put more gas in the engine. If it runs like this you probably have the CO set way too lean to run.

I found the following:
- Using the CPR's grey connector on the CSV had no effect.
- Jumping the RPM relay to run the fuel pump and CSV had no effect.
- Taking off the CSV's fuel line sprayed fuel everywhere (what with it being under pressure)
- Jumping the RPM relay to run the pump with the CVS's fuel line disconnected sprayed more fuel everywhere (I didn't have a jar with me to collect the fuel).
- I got 400 ohms from the pins on the CSV's connector.

I'm thinking that the CSV is plugged up, but I have no idea how I'd clean it. I also don't know if I should feel the valve click open/closed when I apply voltage to the pins; when I try it, I don't feel anything like I do with the idle speed motor. Of course, the idle speed motor is a much larger unit.

-- Joe

[Bitsyncmaster]

My CSV reads 4.01 ohms. You may have just read the meter wrong but 400 ohms would not work the CSV. It takes a few amps to operate the CSV.

[DMCMW Dave]

My CSV reads 4.01 ohms. You may have just read the meter wrong but 400 ohms would not work the CSV. It takes a few amps to operate the CSV.

Or it is really bad.

[jangell]

I think you're both right: First, there's clearly no fuel passing through the CSV, so if it's not electrically bad then it's plugged.

Secondly, I probably read the multimeter wrong. misunderstanding the ranges and how to read them (you'd think I'd know how to do this by now). I happened to take the CSV home, and used a second (different brand) multimeter to test it, and got 5 ohm (after checking the docs to make sure I'm using it correctly).

At this point, I'm leaning towards not only the CSV being bad, but at least some of the five cleaned injectors are probably toast as well (It was worth a shot cleaning them, but David T did say they were the worst he'd ever seen), and although it seems to be working fine I wouldn't be surprised if there was some kind of damage to the fuel distributor as well. Rather than spend $500-$1000 on K-Jet parts just to replace them with EFI parts this fall, I think I'm going to move ahead with my EFI conversion. I know that trying to fix a problem by installing another entire system in its place isn't necessarily the wisest thing to do, especially if my problem isn't actual fuel related, and then I'm be fixing two things at once. But I'm sure everything will go great and I'll have no problems at all. I'll start up an EFI thread when I get closer to getting this going.

Still, I have a couple more tests to try, and maybe if I whack the CSV hard enough it will unclog and let me check out the mechanical advance tomorrow.

Thanks again everyone!

-- Joe

[jangell]

Another update:

I whacked the CSV against the floor a few times to see if I could unstick it, but no go. I did discover how much gas would be sprayed around the engine bay if you run the fuel pump when you've forgotten to tighten down the banjo bolt on the CSV, though.

I followed Dave Swingle's advice and started the car by pushing the air deflector plate down while cranking the starter. I didn't have an assistant, to crank, but I was able to work around this due to a relay I'd installed in the engine compartment to resolve a low-voltage starting issue many years ago (it's basically service bulletin ST-05-2/82, which I thought I had but actually didn't; this mode serves the same purpose). I plugged a momentary push button from Advance Auto into it in place of the relay, which allowed me to crank the engine while pushing down the deflector plate.

IMG_0901.jpgIMG_0928.jpg

The car started without too much trouble, although it was a little tricky to keep it running. I found that if it wouldn't start while I was holding the plate down a little, that releasing it and trying to start it, and then trying again with the plate down a bit would start it. If I released the plate the car would stall after a few seconds, although on my last attempt (after revving it a fair bit while checking the timing) it actually did stay running. At this point I noticed the plate remained slightly opened, never actually closing all the way while the car managed to stay running. I'm not sure if that's normal, or if it's supposed to be completely closed (it is completely closed when the car is off). It ran a bit rough, however; certainly not as smooth as when the CSV is working.

It took me a few tries to juggle pushing the button, holding down the deflector plate, pulling the throttle arm to rev the engine and grabbing the timing light to actually check the mechanical advance (with the distributor vacuum disconnected). It looks like it's working -- I don't know the RPMs (I had a tach hooked up but forgot to actually look at it), but the red dot on the pulley moved to the left (counterclockwise) quite a bit. If I had to throw a number out there I'd say it was at 40 or 50 degrees from 0. I have not put the Bosh plugs in yet, although I did get them; I'm still using the NKG TR5's.


I also tried cleaning the tank out more thoroughly so that I could install the new pump/sender combo. It was clear that this was necessary once I had the baffle out. New pictures show that under the pump and near the back of the tank were pretty dirty. My main problem is that I simply cannot reacy back that far -- my arm won't quite fit in the pump's hole enough to get my elbow in and reach all the way back. I'm thinking of picking up a squeegee or sponge-on-a-stick or something and trying again next weekend. Hopefully the acetone won't dissolve it too badly...

IMG_0961.jpgIMG_0971.jpgIMG_0979.jpg

This picture shows a pinhole leak in the plastic cap of the old fuel pump. I'm guessing this is how water was getting onto the top of the pump and rusting everything. I bet there's a small hole through the rust to the tank itself, too.

IMG_0946.jpgIMG_0951.jpg

Thanks again!

-- Joe