jimjific

I am stumped on this one. I've worked on cars all my life and can't figure this one out.

First the car. 67 Vista Cruiser 330 with Quadrajet carb. Very stock car. Got the car towards the end of summer. Previous owner put in a new tank and the wrong sending unit 30 ohm. I put a 90 ohm unit in and got the fuel gauge working right. Car drove great for about 4 thousand miles street or highway.

Then 10/4 an a-hole fell asleep and hit my wife in the left rear door al they way down the quarter panel. Car still drives.

Now the issue. Ever since the accident I've been having fuel issues. It only seems to happen when the car is on the highway. It sputters and feels like it wants to stall. As soon as you get off the highway, the issue goes away.

- I've changed the filter (removed an in line extra filter that was before the pump)
- checked the float level
- checked the vent tube
- put in a new fuel pump
- Drilled a small hole in the gas cap

I started to think that maybe the issue only happens when the tank was near 1/4 full and that the aftermarket pickup tube wasn't long enough or bent down enough to pick up the bottom of the tank. So today, I disconnected the rubber line to the fuel pump and siphoned from the fuel line figuring that if the pickup wasn't in the 1/4 tank of gas I would not be able to pull any fuel out. Well, I pulled out about 4 gallons and then reconnected the fuel line. The gauge now reads near empty. Well the car still started with and I drove it around the block with no signs of gas starvation.

I'm at a loss. I really need this car to be dependable since it will be my wife's daily driver.

Sorry for the long post but wanted to be thorough in what I have tried. Any thoughts are much appreciated

Thanks,
Jim

MDchanic

You've got either a kinked steel line or a porous or kinked rubber hose either at the tank or before the fuel pump.

Other possibilities are a bad fuel pick-up sock (but you changed the sender) and a cracked fuel pickup line (inside the tank).

Just go through the entire fuel line from the pickup to the pump and you'll find it.

- Eric

jimjific

Thanks for the reply. I will check the hose from the tank to the steel line since I didn't replace t hat yet. I was also wondering could the exhaust flap on the left manifold cause this? It seems to work ok, but it is hard to tell when you are driving. I took it out on a 69 C-10 that I drive. Are there any issues with taking it out?

Thanks,
Jim

MDchanic

The exhaust heat riser can reduce high RPM performance if it is stuck, but if it is operating properly (as essentially none of them are anymore), it should be fine.

Does it open all the way once the manifolds are warmed up?
If so, don't worry about it.

It won't hurt anything to remove it from your average collector car, which is only driven in nice weather, as its purpose is to aid warm-up when it is very cold out, but if it works, it's not worth the hassle to remove it.


And, yes, those rubber hoses from the tank to the steel lines are your chief target - remove them and twist them around your finger - if you see fine cracks, they're toast.

- Eric

Railguy

Which side is the fuel line on could the problem with it be where it's been hi?
Railguy

jimjific

The fuel line is on the right side (passenger) and is all stock. I pulled the tank to steel rubber line out yesterday and it looked fine. I'm replacing it with new hose anyway.

The only thing I haven't done is rebuild the carb. But it seems like a fuel issue since the one time, the carb was completely empty. I got it started only by putting some fuel down the carb vent.

Railguy

have you tried fuel pressure gauge?
railguy

AJFink

Here is something else to look into. While doing my full restoration I found the vent system on my car plugged up. my system has the vent box (lack of a better explanation) that's behind the back seat. Two of the lines where plugged up and the two lines that went to the top of the tank plugged. All of this is just above the rear axle and is connected with rubber lines. Remove the rubber connections and blow out the vent lines.

jimjific

The only vent line on the 67 Cruiser goes from the top of the tank back to the filler neck. I think its only purpose if during filling the tank since the neck goes into the side of the tank. The vent allows the air to escape when the tank level is higher than the neck entry point. I know this vent is clear since one, I've taken it out to check and two, today's pumps must pump faster than the old days since the neck will fill sometime and then I see gas push through the vent line back out into the neck. It usually ends up spilling back out.

I was thinking about a fuel pressure gauge. Do they make one that hooks up into your stock hard line?

Also, I got the new tubing in today and filled up the car. I did a couple of trips no issues. I will have to see as the tank empties how it goes.

Thanks again for all of the thoughts.

Jim

MDchanic

If I recall, you found that the tank level didn't matter before, so I am optimistic.

- Eric

jimjific

Ugghhh! After a couple of successful rides yesterday (about 20 miles worth) it had issues again going to work (it's only a couple of mile drive). I have over 3/4 of a tank so now I can rule out the tank level being the culprit.

This mornings event felt more like a carb issue since as soon as I tried to get into the throttle is stumbles and won't pull the car past 20 mph. I got onto a side road and after a couple of turns the car "woke up" and started running right. So I brought it to work.

Before leave to go home, I will check to see if the choke is set. I know is open when the engine is warmed.

I've had a 69 and a 72 Vista Cruiser in the past and they were just bullet proof. This has become very frustrating.

Jim

MDchanic

Time to start thinking about spark.

Bad coil? Bad condenser? Bad coil high tension wire? Loose/cracked/scuffed hot wire inside distributor?

- Eric

Railguy

Does the Quadrajet have a built-in filter?
Railguy

jimjific

Yes, it does and I've replaced it.

BlackGold

I agree with checking the ignition. My car once started hesitating only at cruise. Turned out to be a loose coil wire, sitting more than an inch above the center contact of the distributor cap. Spark was jumping the gap just fine except, oddly enough, at cruise. Maybe the accident jarred an ignition component loose on your car.

jimjific

Thanks Brian I will check to see if there are any issues. I was planning on getting a Petronix electric ignition since I've had pretty good luck with them. Maybe I'll step up and get one and new rotor and cap.

The ride home was bad. As soon as I started up the one hill it really started to die. I put it in neutral and it revs fine, put it back in drive and it wants to stall under load.

MDchanic

Sounds very electrical.

- Eric

jimjific

Sorry to bug everyone again, but what would you suggest, a Petronix and new coil or an HEI? I have no experience with HEI's but they seem to be relatively cheap. Looks like you can get them for about $85. Plus new wires.

Thanks again,
Jim

MDchanic

You can get them for less than that, if you keep your eyes open, much less in a junkyard.

HEI is fine, but seems like a radical solution to a problem that you haven't even diagnosed yet, plus you will need to use a recurve kit to readjust the centrifugal and vacuum advances to tune it the way you want it to be.

Pertronix will maintain your current timing curves, and is known to work well.
You will only get the full performance potential from it if you also get one of their coils, but if your coil is fine, you may not actually need theirs.

I'd try to figure out the problem first, then make a final decision on an electronic ignition afterward.

- Eric

jimjific

Ok, I did notice one thing that is probably not right. The condenser that is on the coil is not hooked up to anything. Could this cause such an issue? How important is the condenser? I am uncertain if the condenser has been off the whole time I've owned the car. The wire is not broken so it almost seems like someone would have had to disconnect it on purpose. I assume that e condenser should be hooked up to the negative side of the coil? The car seems to be getting worse over time. If this is not the smoking gun, I will switch carbs with my C-10 pickup that has the same Quadrajet and runs perfectly to see if the issue goes away. If it does, I will know it is a carb issue.

Thanks again for all of the help,
Jim

oldcutlass

The condenser on the coil is a for filtering radio noise, its not needed for the engine to run properly. An HEI will work on your engine fine although you can't use your stock timing settings. Its not hard to convert.
You need to figure out if your issue is ignition or fuel related.

jimjific

Eric,

That is what I always thought. I was looking on the internet to see what side of the coil it is supposed to attach too and saw people writing that it suppresses arcing of the points. I will be doing the carb swap.

Thanks,
Jim

jimjific

Here's an update, Well I swapped the Vista Cruiser carb with the Quadrajet from the C-10 and it seemed to run well. I couldn't get the car to do the hesitation thing. I did about 5 miles. I guess I will start the carb rebuild.

Thanks,
Jim

oldcutlass

Hopefully that will fix it.

MDchanic

Well, sounds like it wasn't electrical.

Glad you narrowed it down!

When you rebuild it, look at it carefully to see whether you can find the problem, so that you know you've fixed it, and you can tell us what it was.

- Eric

jimjific

Update,

Finally got the carb rebuilt this weekend. No big surprises other than one of the primary rods looked a little bent at the tip. I bought a new set of rods with the rebuild kit. The only other thing that I noticed was that the float needle clip was attached to the float through the holes in the pivot bracket. According to Doug Roes book, the clip should just hang on the lip of the float.

Anyway, the car has not done the stumbling issue yet. I have only made a few trips nothing too long distance wise. I also got my Petronix ignitor 2 in the mail today. I will put off putting it in to see if I have really solved the problem with the carb.

Thanks,
Jim

64Rocket

Have you check all the rubber hoses along the whole length of the fuel line? From the back along the frame up to the fuel pump.

Gene

jimjific

Gene,

Yes, they looked ok, but I changed them out anyway.

Thanks,
Jim

jimjific

Here is an update to this issue.

I think I finally found the smoking gun with my issue.

After the carb rebuild, the car seemed to run better, but it still seemed to have a flat feeling when you are doing about 25mph and push the throttle in. Hard to describe, but it just didn't feel right or instill confidence for a really long trip. So this weekend I finally got to putting in a Petronix ignition that I bought a while back. I took someones advice and bought the service manual off of e-bay. Glad I did, it looks like a great resource. Anyway, I replaced the resistor wire and got the coil all set up. Then came the Petronix module. I pulled the dist. cap off and then the rotor. Next came the points. Once that was removed I looked down at the base plate and noticed that the ground wire that goes from the vacuum attaching point to the base plate was broken where it is crimped onto the plate.

Well, this can't be good. So I reattached it and finished the install. Car now runs great through the entire rpm range.

So here is my thinking. Since the wire was there and would make partial contact say at idle, it seems to fit that when you would try to accelerate the vacuum would move the plate causing the complete disconnect and a resulting stumble until the distributor moved back. It also seems to make sense that my issue was intermittent.

So Eric, it sounds like you might have had it right all along.

Thanks to everyone for their advice along this journey,
Jim

classicmuscle442

Great job troubleshooting, nice to find the true source, I would of bet that it was fuel related.

76olds

[QUOTE=jimjific;985062]
So here is my thinking. Since the wire was there and would make partial contact say at idle, it seems to fit that when you would try to accelerate the vacuum would move the plate causing the complete disconnect and a resulting stumble until the distributor moved back. It also seems to make sense that my issue was intermittent.

So Eric, it sounds like you might have had it right all along.

Thanks to everyone for their advice along this journey.


I couldn't add any advice with your issue, however, I followed along closely. Your thread has been very informative to myself and most likely many others.
Awesome post and trouble shooting skills Jim, very much appreciated!!

Cheers
Eric H

MDchanic

Well, not all along. Initially, I thought it was a fuel supply restriction.

I only went with electrical after you described the problem a little bit differently.

But, yeah, you've really got to look at the entire ignition system when the car does stuff like this, which, best of all, doesn't cost anything.

And, yes, you've described the nature of the problem perfectly: vacuum level determines points plate position, and the ground is tenuous or intermittent in some positions, so when you've got to press the gas pedal farther, the points plate moves more, and the ground path is degraded. There is probably some degree of ground connection through other metal components, so it's not all or nothing, but the connection is not 100% constant, and has more resistance than a functioning ground strap would.

Glad you got it fixed, and that you got your carburetor rebuilt!

I hope your wife doesn't hate the car by now ("I don't care if it's fixed - I don't trust it!").

- Eric

jimjific

Funny comment about the wife. She is a little leery about the car now. I've actually been driving it to work out the bugs. And now that it seems to be running right again, it's time to work on fixing the damage done from the accident. I got right rear quarter from Desert Valley last week. It will need some work, but it's a good piece.

Jim