WTF?! Engine troubles... (1 Viewer)

[FineWynsFJ40]

My engine won't stay running for longer than 3 seconds. I jammed on the brakes pretty hard, right before hitting the clutch, which is the root of this trouble, so it won't idle very well and won't do anything ABOVE idle. I rebuilt the carburetor, but need to set the idle speed, and rebuilt the dizzy. I can't take a timing light to it because it won't run long enough to do so, and I can't figure out why it would do that after a hard brake? I have been over every inch of that engine bay looking for loose hoses, etc., but can't find any. Am I going to have to bite the bullet and *gulp* overhaul it to fix the gremlin, or is there an easier (and less expensive) option?

P.S. How hard and time consuming is rebuilding the engine yourself, versus having somebody do it for you?

Thanks, I really need this help to get her running again before tempers flare and a 5 lb. pickaxe goes to town.

 

[Poser]

This is a repost.....

 

[Poser]

I knew it.....


https://forum.ih8mud.com/showthread.php?t=50637

 

[red dirt squirt]

excellent detective work........thats legendary status

 

[FineWynsFJ40]

Well, I didn't get any good responses the first time, so I figured may as well give it one last shot. Come on people, I need help here! My cruiser sits now as an expensive paperweight in the garage, and summer is slipping away! Any and all suggestions would be great, are much needed, and will be appreciated.

Thanks.

 

[IDave]

So, FineWyns, did you check to make sure the carb solenoid is working?

You say you haven't set the idle speed/throttle yet. Try turning it up a bit.

Can't think of any reason you would have to rebuild the engine, or how it would do you any good.

 

[NJFJ40]

Have you checked the PCV hose and valve connection? Mine came loose once during some rough riding - but still ran just really rough and barely idled.

The PCV Valve just seats into a flange on the PS of the block near the firewall. I would guess hard braking could possibly jog it loose so don't just check the hose connection - also make sure the valve is seated properly.

AndrewT

 

[FineWynsFJ40]

IDave, there is no idle solonoid, it's a manual choke. I have tried to fiddle with the mixture/idle after I rebuilt it, but it still won't run more than a couple seconds, so setting idle is impossible. I'll check the PCV hose and assembly, change the oil tonight, and if the parts came today, then I'll replace the fuel filter and sump the tank.

Actually, come to think of it, the gas station where I last filled up was a pretty rough place, and I'm wondering if there wasn't a bunch of crap that got in the tank and clogged my filter when I braked... I mean, that place was the pits! I still can't really think of how or why a hard brake would affect anything, for I'd been bouncing around the previous couple of days on rocks and things, so it seems that it would've already happened... Thanks.

 

[Degnol]

"IDave, there is no idle solonoid, it's a manual choke."



Uhhhh, these are not mutually exclusive. The idle solenoid cuts off fuel to the idle circuit to prevent run-on and dieseling. The choke is, well, the choke.

There should be a wire connected to the carb that opens the idle solenoid when the ignition is on.

I take it that the thing will run above idle speed, but just not idle????


Dave is right, you can turn up the idle speed adjustment screw at the base of the carb to start your diagnostics.


My guess is the panic stop either sent some grunge into your carb, or the idle solenoid has lost its power wire.




Can you post a pic of your carb so we know what you have???



GL

Ed

 

[Pighead]

Or maybe last panic stop ripped brake booster diaphragm and now you've got a big vacuum leak?

 

[e rock]

Well, I didn't get any good responses the first time

That's the way to get some good help. There were plenty of helpful suggestions in your original thread. Have you gone through all of those?

 

[IDave]

IDave, there is no idle solonoid, it's a manual choke. .

As Ed pointed out, manual choke and idle solenoid not mutually exclusive at all. Even the later 1 barrel carbs had them. My manually choked 2 bbl certainly does. Post a picture of your setup and we can tell pretty quickly.

When I reattached my carb (had it off to mess with the engine) I installed the cable accellerator linkage slightly differently (held in by two nuts and adjustable). I guess I had tension on it before, so the throttle was hanging on the cable, not hitting the stop (but idling correct speed). So I must have installed it a bit looser this time. I had to turn in the idle speed adjust screw in to make it run, else it was just like what you experienced.

 

[FineWynsFJ40]

I should have been more specific, it is a GM Rochester 2 jet carb. I have rebuilt it according to instructions found in the rebuild kit and a book I have, so it isn't the carb. However, I inspected the PCV and found it to be faulty, so I think that this is where most (if not all) of my troubles are coming from. The gas I got isn't the best quality, and I will sump the tank and clean my fuel filter. I am yet to clean and service my PCV, and will try it later tonight. How do I check the brake booster diaphram without the engine running?

E Rock, you're right, my wording choice was bad, I apologize for any feelings hurt. :whoops: I am very grateful for all of the help and suggestions. I have checked all of the things in my earlier thread, and have gone through them individually. The distributor is in its' proper place, and I cleaned the contacts on everything and made sure it was in 100% condition. All hoses and lines are in their proper places with no leaks detected, so I think it's the fuel filter and PCV. I'll try to get those squared away tonight, and post the results.

Thank you all very much for helping me work my way through this. This is my first time doing an in-depth fault-diagnosis, and I got a little rattled when I couldn't figure it out on my own. I really appreciate and respect the quality of the people on this forum. Thanks.

 

[ranger]

First thing I would have checked is what you did to initally have the problem. You said that you hit your brakes really hard and it wouldn't idle any more than 3 seconds after that. My first guess would be the brake booster or check valve. Disconnect the hose to the booster and plug it. If it runs, that was your problem.
You might want to buy a service manual and start reading, it will save you alot of time and money on swapping and rebuilding parts. If you really don't know what you are doing you can make a small problem a major nightmare.

 

[FineWynsFJ40]

Thanks Ranger. I do have some idea, and have a manual. I have tried all the simple things already, it won't run NOW for more than 3 seconds, although when it happened it would idle all day, probably due to it being warmed up. I should have specified that in the beginning. Last night I discovered:

The PCV valve is faulty, so I will replace that, and when I went to pull the plugs and change oil for routine maintenance, I discovered black stuff caked onto the plug, with which were small pieces of debris. I then cut open the old oil filter, very carefully, and discovered: Copper shavings/shrapnel!!

With copper shavings in the engine (and other things, possibly dirt, I think the previous owner didn't take as good of care of it), I now do not want to run it. Is it the piston rings, and would distinegrated piston rings cause the problem of backfiring/bucking/not running well at all? Second question is what is the timeframe/cost/difficulty in doing an overhaul/rebuild, and is it worth it to have a professional place do it, especially since I have very little time to mess with something so complicated and tedious as an engine?

BTW: I'm posting right after work, before I can prod around a little. I'm working as a cherry picker, so 12 hour days and no days off for 3 weeks straight chew into free time/cruiser time like none other! Thanks, I appreciate all the help.

 

[Pin_Head]

My engine won't stay running for longer than 3 seconds. .

If it runs at all, it is not fundamentally a timing issue. It sounds like it is running out of gas. Does it run longer if you pour gas in the carb. Is your fuel pump pumping enough gas?

The PCV valve is faulty, so I will replace that,
Is it the piston rings, and would distinegrated piston rings cause the problem of backfiring/bucking/not running well at all?

The PCV doesn't have anything to do with it. Bucking and backfiring through the carb are classic fuel starvation symptoms.

The kind of thing I would think of since it happended when you stopped quickly is that you dislodged some crud in your fuel tank that is blocking the opening.

 

[ranger]

Thanks Ranger. I do have some idea, and have a manual. I have tried all the simple things already, it won't run NOW for more than 3 seconds, although when it happened it would idle all day, probably due to it being warmed up. I should have specified that in the beginning. Last night I discovered:

The PCV valve is faulty, so I will replace that, and when I went to pull the plugs and change oil for routine maintenance, I discovered black stuff caked onto the plug, with which were small pieces of debris. I then cut open the old oil filter, very carefully, and discovered: Copper shavings/shrapnel!!

With copper shavings in the engine (and other things, possibly dirt, I think the previous owner didn't take as good of care of it), I now do not want to run it. Is it the piston rings, and would distinegrated piston rings cause the problem of backfiring/bucking/not running well at all? Second question is what is the timeframe/cost/difficulty in doing an overhaul/rebuild, and is it worth it to have a professional place do it, especially since I have very little time to mess with something so complicated and tedious as an engine?

BTW: I'm posting right after work, before I can prod around a little. I'm working as a cherry picker, so 12 hour days and no days off for 3 weeks straight chew into free time/cruiser time like none other! Thanks, I appreciate all the help.

The black crud on your plugs is carbon, either from running to rich or burnt oil. Replace them and gap them to specs. Copper for the engine usually indicates bearing wear, not rings.

 

[honk]

I'd look at the carb float sticking.

 

[FineWynsFJ40]

Alrighty, I got some time off of work due to breakdown to run to my local Car Quest. The guy there said bearings, yep, and also possibly a shim or spacer with the valve springs? A theory I came up with is that the oil rushed to the front of the engine, splashing up on the springs, carrying some metal flakes with it, into the engine and oil ways. At the same time, crud from the tank clogged the filter, creating the loss of power and backfiring. Just a theory, please correct me if I'm wrong. I'll change the oil filter and oil tonight, as well as sump the tank and replace the gas filter (finally came in).

Honk, I just rebuilt the carb, so it shouldn't be that, although if the other stuff I try doesn't work, I'll pop the top off and have a look, but if it was the case it shouldn't affect it after the rebuild if it was doing it before? I'll check anyways, thanks.

The guy said to pull all plugs, which I did, and to crank it a couple times so the compression can blow the chunks out. I'll give it a try, as I may as well try to get it running, for if I have to rebuild it, I may as well be damn sure!! I'll do a compression test, picked up a tester today. What are normal tolerance numbers? Within 15%, but what is the usual target #? Thanks. Tonight I find out the truth...

 

[FineWynsFJ40]

Results:
1. I sumped the gas, yep, there was crud and fuel filter was partially clogged. Replaced and drained, fuel line is 100% now.
2. Drained oil, replaced filter. I stuck my finger up inside the oil pan, and there were BIG chunks of things there that I couldn't get out without taking the oil pan off.
3. Replaced PCV.
4. Replaced spark plug ignition wires
&
5. Cleaned cylinders by cranking w/out plugs in, and then compression test yielded the following results of:
Cyl #1 (front) - Cyl #6 (rear) = 115, 90, 110, 105, 110, 130

Something is wrong with this picture... Poser, some help here please?

Edit: I believe I didn't test the compression properly, as I can't warm the enginee up, but also didn't have the throttle plates open all the way... I'll try cranking her up tomorrow to warm her up, and then compression with throttle plates open all the way.