1989 K5 - Gradual Learning

[mrk5]

It used to be a TBI350 thing I read here on CK5 to advance the base timing to 5° BTDC instead of 0°. Back in the day when the TBI swap was what the LS swap is today.

 

[Wes Harden]

Yeah I am thinking it either has an emissions chain set with retarded cam timing, or the chain has a little stretch. Could be the nylon gear is going tits up, and why performance keeps changing.

Advancing the distributor timing will help a little, if this the case.

 

[shima]

Thought I would check-in with you all. Going to get out and work on the Blazer today. 60 degrees and sunny out, can't miss this chance. Also I'm doing the whole quarantine thing because a buddy tested positive for COVID. We skateboarded together a few days before his test came back positive so... no better time to work in the garage.

Goals today are to change the oil just for peace of mind... it smelled a little gassy last time I went out there. Could not light it on fire, but I have some spare oil in the garage and I'll feel better just doing it. Then I am going to advance the timing 4 degrees with EST disconnected and drive it around. When I was out last time, I did notice a really bad vibration coming from the engine at idle. Not sure if that proves I have a dead cylinder or if that could be timing related. Either way if the advanced timing doesn't help much I'm going to buy the tool that @ZooMad75 linked on the last page. I am tempted to buy 8 of them and check all 8 cylinders at once!! lol. Just turn off the garage lights and look at all 8 indicators at one time. That would be kind of fun.

 

[shima]

This thing is f***ed. Bought the in-line spark indicator tool. Checked all 8 cylinders. Light flashes for all 8. Advanced timing to about 5 degrees, drove it, still hard shaking / vibration and low power.

I recorded some videos and took some photos. Will post those soon. Really scratching my head here.

 

[Wes Harden]

Might time to do a compression test.

Edit: be

 

[FallGuy86]

I could dig thru the shed, I've got a nice compression test kit still in the plastic.. somewhere.

 

[Capt Ron]

How goes the battle?

 

[shima]

@Capt Ron thanks for checking-in man. I haven't made much progress. I herniated a disc in my back and have been laying low.

The spark plug indicator tool that I bought is the one that @ZooMad75 linked one page back. It fits really snug onto the spark plug, but the other end of it doesn't fit snug/tight inside the spark plug wire. It's really loose. So I was seeing the light flash brighter for some plugs than other plugs, but I am worried that was only because there was not good contact between the tool and the inside of the spark plug wire. Also I did the test during the day with the lights on inside my garage. I sort of want to do the test again with the lights off so that I can record clearer video of what's going on. I'll probably climb up into the engine bay 8 separate times to make sure that the tool is making good contact with the plug wire. Hoping I don't get shocked again.

Anyhow my plan is to do the test one more time and record the videos like I mentioned and post up in the Tech Section of the forums. I'll just give a basic overview of the symptoms and the history and see where it goes from there.

 

[shima]

Went out to the garage tonight to try and start up all of my junk. I realized that I haven't done a good job of starting stuff up regularly and that I need to do a better job of that.

Status report:

• Sportster
  • Started with some convincing, ran fine once warm.
• K30
  • Wouldn't start. Cranked many times with no go. I think I tired out my starter. Never had an issue starting the truck while warm so I'll try again tomorrow. That big block must be real cold.
• Blazer
  • Started after a couple of tries on the key. Harder to start than normal. Barely stayed running, lights were flickering and it was vibrating bad. I shut it off after maybe 10-15 seconds.

When the Blazer was running I noticed the check engine light was on and it stayed lit. So, I checked the codes and now have some new clues for my issues.

CODE 42 ELECTRONIC SPARK TIMING

CODE 44 LEAN EXHAUST

Never seen those codes before on my Blazer. Gonna do some research on the site and see if I can figure out what's going on. If it is running lean then perhaps that explains the low power and the vibration at idle?

Timing is still advanced 5 degrees.

 

[HankScorpio]

Went out to the garage tonight to try and start up all of my junk. I realized that I haven't done a good job of starting stuff up regularly and that I need to do a better job of that.

Status report:

• Sportster
  • Started with some convincing, ran fine once warm.
• K30
  • Wouldn't start. Cranked many times with no go. I think I tired out my starter. Never had an issue starting the truck while warm so I'll try again tomorrow. That big block must be real cold.
• Blazer
  • Started after a couple of tries on the key. Harder to start than normal. Barely stayed running, lights were flickering and it was vibrating bad. I shut it off after maybe 10-15 seconds.

When the Blazer was running I noticed the check engine light was on and it stayed lit. So, I checked the codes and now have some new clues for my issues.

CODE 42 ELECTRONIC SPARK TIMING

CODE 44 LEAN EXHAUST

Never seen those codes before on my Blazer. Gonna do some research on the site and see if I can figure out what's going on. If it is running lean then perhaps that explains the low power and the vibration at idle?

Timing is still advanced 5 degrees.

Start it again and warm it up. Those codes could mean nothing at this point. Old truck, cold, etc. 10-15 seconds isn't enough to rely on.

 

[Wes Harden]

yeah shouldn't have even tested for problems in 10 or 15 seconds, not until closed loop.

 

[imiceman44]

Went out to the garage tonight to try and start up all of my junk. I realized that I haven't done a good job of starting stuff up regularly and that I need to do a better job of that.

Status report:

• Sportster
  • Started with some convincing, ran fine once warm.
• K30
  • Wouldn't start. Cranked many times with no go. I think I tired out my starter. Never had an issue starting the truck while warm so I'll try again tomorrow. That big block must be real cold.
• Blazer
  • Started after a couple of tries on the key. Harder to start than normal. Barely stayed running, lights were flickering and it was vibrating bad. I shut it off after maybe 10-15 seconds.

When the Blazer was running I noticed the check engine light was on and it stayed lit. So, I checked the codes and now have some new clues for my issues.

CODE 42 ELECTRONIC SPARK TIMING

CODE 44 LEAN EXHAUST

Never seen those codes before on my Blazer. Gonna do some research on the site and see if I can figure out what's going on. If it is running lean then perhaps that explains the low power and the vibration at idle?

Timing is still advanced 5 degrees.

When it's really cold like I know it is there now it's normal to run rough like that for a little bit, you need to let it run till it warms up and smooth out.
You should hear what my big rig sounds like when I started it in Colorado in the winter and that was every day. You let sit for a while and it is worse

 

[mrk5]

Sometimes carbs can really be hard to start cold. Sometimes the fuel bowls are just dry and need to be refilled.

I've said it in lots of places on CK5, but if you're running a carb these days I would highly recommend buying alcohol free gas.

 

[shima]

Hey thanks guys for the responses.

I went out and started it just now. It stayed running but man is it angry. The idle sounds more metallic, like something is getting chewed up inside the engine. Yikes.

Here is a video in case anyone wants to listen to it (be warned it is loud if you are using headphones):

Sometimes carbs can really be hard to start cold. Sometimes the fuel bowls are just dry and need to be refilled.

I've said it in lots of places on CK5, but if you're running a carb these days I would highly recommend buying alcohol free gas.

Yeah, I think @Wes Harden mentioned that as well on my K30 build. Only two gas stations in Denver metro according to pure-gas.org... might be worth the trip out to them since I don't drive the K30 that often.

 

[mrk5]

Murphy USA and Maverick stations around here have it. It's usually mid-grade, but sometimes it's only available in premium. But I can tell the carb runs smoother with the 0 ethanol stuff. It think it's especially a good idea for a vehicle that sits more.

 

[Wes Harden]

If not able to get ethenol free, use an additive. I use Lucas, the only ethenol free is in 5 gal cans and $50+ .
That sounded horrible. Did it have oil pressure? What is the temperature and what weight oil is in there?

 

[shima]

If not able to get ethenol free, use an additive. I use Lucas, the only ethenol free is in 5 gal cans and $50+ .
That sounded horrible. Did it have oil pressure? What is the temperature and what weight oil is in there?

Yeah it really sounded awful. I didn't look at the oil pressure gauge while I was out there. I'll check it next time I start it up. The temp in the garage was probably 45 degrees, and I believe that there is 10w30 in there.

 

[Wes Harden]

Yeah not that cold, and 10 30 should be fine at that temp.
Has anyone ever checked the timing chain?

 

[shima]

The PO told me that they pulled the motor out of a Suburban and had it machined and whatnot. This was 6 months to a year before I bought it in 2017. I can't imagine they did all that without looking the timing chain over but who knows. I haven't ever checked it.

I said earlier in this thread that I would change the oil for peace of mind and I didn't do that. My reasoning was that I changed it just recently (back in June). But with these sounds coming from my truck perhaps I should change it just to see the condition of the oil that comes out.

 

[Wes Harden]

Well what my phone represented of your recording may not be what the motor sounds irl. So maybe nothing to it just a cold motor.
If they machined the block in anyway it should have been totally disassembled.
If only did the heads then the chain may be original. 70 to 90k is about it on a SBC factory chain and gears