230 issues (again)

[jdl71]

So after this issue was resolved it ran great. I was driving it a few miles a week and noticed it started getting harder to start, idling worse, needing more and more choke until now when it won't idle at all. It will only run with the choke almost all the way shut and it sounds like the engine is going to run away, it's going probably 3000 rpm without touching the throttle. It also has what is best described as a popping or sputtering almost helicopter type sound from the exhaust. An attempt to open the choke results in backfire through the carb and dying. Sound like a massive vacuum leak? I have tried spraying carb cleaner around all possible spots while it was running and couldn't find anywhere that made a difference. I am running fresh gas out of a can using an electric pump. I have checked timing. I have swapped with a spare carb. I have checked point gap. I pulled the plugs and they are clean. Plugs,wires, cap, rotor condensor and points all have about 50 miles on them. I pulled the valve cover and turned the engine over and everything seems to be moving like it should. Help....

http://www.youtube.com/watch?v=jW_cPU4BjOU

http://www.youtube.com/watch?v=xaFDDypyXtI

[Backpayne]

Sounds like a vacuum leak, yet, you say you've sprayed to find one and can't. Did the intake manifold come loose a little or the gasket blow out?

[jdl71]

I grabbed the manifold and tried to move it, nothing. Did the same thing with the carb. I'm using a remflex gasket. It is the only one I could get to seal the exhaust, they are very soft and thick and seal very well. I tried shining a flashlight between the gasket and manifold and head and did not see any light penetrating the other side. I have not put a wrench on the bolts yet, (going to do that tomorrow) but nothing seems loose. I also pulled the pcv out while it was running and was getting quite a bit of vacuum.

[TJ's Chevy]

By the popping that thing sure seems to have either a Huge vacuum leak, or valves are to tight, or something. Did you adjust the valves?

[jdl71]

I did not adjust the valves. I did take the valve cover off and can spin the pushrods when the valves are closed. I was thinking that maybe I had bent one and a valve is stuck but everything appears to be moving normally.

[maxwoof]

Before the engine gets too hot, with the engine running, you could try running water over the manifold/head joint, carb base, anywhere you could have a vacuum leak. Use a hose or a watering can. If there is a vacuum leak, you will hear the sound of the engine change. I once had a chunk of carb gasket break off causing a leak, which I found this way. I would also try running it with the PVC plugged to eliminate that as a possibility.

I would also make sure al the ignition components are in good shape. Bad coils can cause erratic problems that appear to be fuel related. I would agree wit others that you have a vacuum leak because of the back firing and engine speed increase, but another possibility that could cause similar symptoms could be advanced timing if the distributor moved or if the distributor is advancing for some reason.

Start with the easy stuff and good luck with it.

[jdl71]

I swapped with a spare coil. I put a wrench on the intake bolts and snugged up. I can not seem to get any reaction by spraying carb cleaner around the intake surfaces with the engine running. I'm about to start looking for a small block v8. I need this to run somewhat reliably and am tired of fighting it. Thank you for the suggestions.

[63ChevC10]

Sorry to hear about your troubles. I have the same engine in my 63 and it was doing almost all of what you're describing. I also tried the things you've tried. The fix for mine? An HEI distributor. It's been about 9 months since I installed it and I'm still amazed at the difference. It literally runs like I put a new engine in it. Anyway, just a thought man. Good luck!

[TJ's Chevy]

Originally Posted by jdl71

I swapped with a spare coil. I put a wrench on the intake bolts and snugged up. I can not seem to get any reaction by spraying carb cleaner around the intake surfaces with the engine running. I'm about to start looking for a small block v8. I need this to run somewhat reliably and am tired of fighting it. Thank you for the suggestions.

What's interesting is the fact it runs right at 3K and sounds like it's the valves aren't sealing. The symptom is almost the same as ripping the hose off the PCV port on the carb and letting the engine run away. Might be time for a new engine, wish I could come and help you with that one. 6 cylinders have normally been pretty easy for me.

[jdl71]

I was going to rebuild the original 230 that was in it but wanted to wait until this fall. Looks like I'll be getting the chance sooner.

[68gmsee]

Just in case, do a compression test on each cylinder. If the sound of the exhaust changed and it wasn't like that before, it may be a stuck or not working intake valve.

[TJ's Chevy]

Since Geezer hasn't chimed in I'll ask. lol What about the timing? I have to wonder if it jumped, or if the dizzy moved. You might try firing it and then retarding the timing to force the engine speed down, and see if that does anything. Something is causing it to almost run away while running extremely rough. Almost like a diesel running on it's own oil.

[jdl71]

Funny you mention that, I was just getting ready to post. I am more and more inclined to believe something has happened to the valve train. Before I posted any of this I reset the timing to zero. Aligned the mark on the balancer and then pulled the cap to verify the rotor was pointing at number one. Yes, I realize this could still be off but before this started I had it set that way, then gave it about 10 degrees advance with the timing light and it started and ran great. It now acts like it wants way more timing than I can give it. I kept moving the distributor towards advance, and it would gradually run at lower rpms without dying until the vacuum advance can hit the block. I've heard before about an engine "jumping time" but never really understood what that meant. Is it possible for the chain to actually come off, move a a tooth or two and the grab back on? I didn't really think so, but I don't know...seems like if that was the case it would have happened all at once, not gradually like it did. Compression test is next on my list.

[jdl71]

Originally Posted by TJ's Chevy

What's interesting is the fact it runs right at 3K and sounds like it's the valves aren't sealing. The symptom is almost the same as ripping the hose off the PCV port on the carb and letting the engine run away. Might be time for a new engine, wish I could come and help you with that one. 6 cylinders have normally been pretty easy for me.

It doesn't run right at 3k (as in correctly), it just runs. Still has all the popping and carrying on like a Huey.

[TJ's Chevy]

Originally Posted by jdl71

Funny you mention that, I was just getting ready to post. I am more and more inclined to believe something has happened to the valve train. Before I posted any of this I reset the timing to zero. Aligned the mark on the balancer and then pulled the cap to verify the rotor was pointing at number one. Yes, I realize this could still be off but before this started I had it set that way, then gave it about 10 degrees advance with the timing light and it started and ran great. It now acts like it wants way more timing than I can give it. I kept moving the distributor towards advance, and it would gradually run at lower rpms without dying until the vacuum advance can hit the block. I've heard before about an engine "jumping time" but never really understood what that meant. Is it possible for the chain to actually come off, move a a tooth or two and the grab back on? I didn't really think so, but I don't know...seems like if that was the case it would have happened all at once, not gradually like it did. Compression test is next on my list.

If some of the teeth broke then it could easily jump. These don't have a chain but have two gears. If the teeth somehow stripped or broke....which is really rare....then the timing could jump causing it to run at higher rpms and much rougher. And with all the effort it took to start it almost seems like it's way to advanced.

[68gmsee]

Re. jumping the cam gear teeth.

Unless it was changed, a lot of cam gears in these engines used the fiber type gear. Not sure if yours has it but the teeth will strip after time and can give you similar symptoms. Place the engine at TDC with #1 in compression stroke and check the timing mark on h-balancer lines up with TDC or "0". That will let you know real quick.

Cam gear pic of one with broken teeth. I had one that stripped three or more teeth.

[jdl71]

I'm still not ready to buy the "jumped time" scenario just yet. It did not just start running poorly one day, it gradually got to this point. I've also read these distributors can be problematic, but once again something mechanically breaking or failing I would think would lead to an instant issue.

[Oberon67]

Originally Posted by jdl71

I'm still not ready to buy the "jumped time" scenario just yet. It did not just start running poorly one day, it gradually got to this point.

What if one of the gears was slipping on the shaft?

[jdl71]

Originally Posted by Oberon67

What if one of the gears was slipping on the shaft?

Idk, if that was the case wouldn't the timing just be getting farther and farther off until it wouldn't run at all? Really not sure, but I'm going to post some info in just a sec, might make a difference to someone smarter than me.

[Oberon67]

Originally Posted by jdl71

Idk, if that was the case wouldn't the timing just be getting farther and farther off until it wouldn't run at all?

Yes, and it sounds like you're on your way.
Posted via Mobile Device

[jdl71]

Compression

1) 150
2) 145ish
3) 135 (a few drops of oil brought it to 150, so rings not valves)
4) 155
5) 140
6) 150

I don't see anything slapping me in the face here, but if someone else does please chime in.

Now on to timing. With the timing mark on the balancer at zero, #1 has already started back down. When #1 was at TDC I would estimate the rotor was close to one cylinder behind which is just what I was getting the other day when I kept trying to move the distributor CCW to get it to run better. In my previous post I think I was getting advance and retard confused, but what it seems to want is spark later rather than sooner, which would make sense by what I saw tonight. However, I put this distributor when I put this engine in and it has probably been like this since then and it used to run right. I guess the next thing I am going to do is pull the distributor and clock it a few degrees, and stab it back in based on what the piston is doing and ignoring the balancer marks to try to get some more adjustment out of it.

[jdl71]

Originally Posted by Oberon67

Yes, and it sounds like you're on your way.
Posted via Mobile Device

Good point. Guess I wasn't seeing the trees for the forest.

[68gmsee]

Originally Posted by jdl71

I'm still not ready to buy the "jumped time" scenario just yet. It did not just start running poorly one day, it gradually got to this point. .....

jd, the info I posted was for reference only. Just to let you know some of these engines came with the fiber type cam gear that will wear or break off some of the teeth. I actually have had two of them give out on me, but as you have mentioned, the failure wasn't gradual but suddenly.

The compression seems to be within tolerances and doesn't indicate a bent or stuck valve. In the past, the only things I've had that gave me similar symptoms were either fuel or ignition related. The fuel issues were a bad fuel pump (ran okay at lower rpms and bogged bad as I gained speed), clogged filters, contaminated fuel and restricted fuel line from tank to the fuel pump. The ignition failure was a bad coil and points/condenser loose wire in my old distributor.

Good luck.

[jdl71]

Originally Posted by TJ's Chevy

You might try firing it and then retarding the timing to force the engine speed down, and see if that does anything. Something is causing it to almost run away while running extremely rough. Almost like a diesel running on it's own oil.

I did this. Sounds like it's hitting on maybe 3 cylinders now and still popping. I found TDC by the piston, the balancer mark is way off, and had to move all the plug wires back one spot to get enough twist in the distributor to get it to slow down. I also checked my wires three times, 1-5-3-6-2-4

[TJ's Chevy]

Originally Posted by jdl71

I did this. Sounds like it's hitting on maybe 3 cylinders now and still popping. I found TDC by the piston, the balancer mark is way off, and had to move all the plug wires back one spot to get enough twist in the distributor to get it to slow down. I also checked my wires three times, 1-5-3-6-2-4

Yep, really sounding like the timing gears jumped or maybe the dizzy gear is stripped.