ohm check the coil wire while you have the meter out. 3000-7000 ohm per foot, is acceptable for carbon core wire.
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
1989 K5 - Gradual Learning
- Thread starter shima
- Start date
First 4x4 - learning basic maintenance / upkeep and maybe some small mods.
I got the new stuff in:
Two plugs smelled like gas and I found a crack in the electrode strap on one of those two. I decided to get new plugs from the parts store (AC Delco CR43TS).
I get everything installed except for the coil... so just new plugs and wires. Fire it up and it fires off fine but dies almost immediately. I tried again and the same thing happened.
I thought no harm in resetting the IAC once more, so I do that. I give it a little pedal to keep it running. When I let off of the pedal it sounds terrible but stayed running for about 30 seconds and then died.
I verified that the injectors are spraying fuel, and I don't think I got the firing order wrong because I replaced one wire at a time. I'll have to take another peek at it tomorrow. Had to just call it a night. I'm bummed out but will keep on keeping on.
EDIT: I suspect the timing may need to be readjusted, I am going to start there.
- AC Delco Wires
- NGK Coil
- Lisle Spark Plug Boot Remover Tool
Two plugs smelled like gas and I found a crack in the electrode strap on one of those two. I decided to get new plugs from the parts store (AC Delco CR43TS).
I get everything installed except for the coil... so just new plugs and wires. Fire it up and it fires off fine but dies almost immediately. I tried again and the same thing happened.
I thought no harm in resetting the IAC once more, so I do that. I give it a little pedal to keep it running. When I let off of the pedal it sounds terrible but stayed running for about 30 seconds and then died.
I verified that the injectors are spraying fuel, and I don't think I got the firing order wrong because I replaced one wire at a time. I'll have to take another peek at it tomorrow. Had to just call it a night. I'm bummed out but will keep on keeping on.
EDIT: I suspect the timing may need to be readjusted, I am going to start there.
Last edited:
I uhhh...
I had forgotten to reconnect the IAC after disconnecting it. It runs fine now.
The stumble while in gear is still there, but it's a lot less harsh (i.e. I don't believe it would die on me anymore). I am going to go through a few key cycles and see if it smoothes out further.
I had forgotten to reconnect the IAC after disconnecting it. It runs fine now.
The stumble while in gear is still there, but it's a lot less harsh (i.e. I don't believe it would die on me anymore). I am going to go through a few key cycles and see if it smoothes out further.
I'm still leaning towards the EGR.
Martin
Martin
This stumble issue has been around for a long time, and I've been getting consistent EGR codes for a long time.
Educate me a little bit... if I have confirmed that the EGR is fully closed and I have also plugged the vacuum line to it... could it be contributing to the stumble?
I would have guessed no, which is why I've been ignoring my EGR for so long.
The stumble happens as you tip into the throttle? Less noticeable with a gradual pressure on the throttle, and more noticeable with quick opening of the throttle?
Fixed multible TBI stumbles by fixing the EGR.
Martin
Martin
Egr valves are fairly cheap, seems like it'd at least be worth a shot to put a new one on.
After replacing the torn spark plug wires and whatnot, the stumble is not detectable when my foot is on the throttle. The K5 accelerates smoothly and drives like a dream. When I come up to stoplight and I take my foot off the throttle, it stumbles. So I'll be sitting at a stoplight shaking. Then when the light turns green I hit the gas pedal and the shaking goes away.
Back in the day (when I first saw the EGR code), I replaced the EGR valve. Then the code kept showing and I replaced the EGR solenoid. Then the code kept showing and I gave up. I do have the shop manual diagnosis steps printed out and they're laying around in my garage. I should try to go through them again. I know a bit more now than I did back then when I first printed them off.
Ok that symptom closer resymbals a miss fire at idle.
Which could be as simple as idle speed, or vacuum leaks.
I know you and Rob gave it a thorough vacuum leak check.
Martin may correct. The egr may still be leaking air/exhaust into the intake. A bad egr valve base gasket, warped base, or dirty pintle all could be the source.
Either a new valve, block off plate or manifold w/o egr.
Since you need an emissions test I suggest a new valve. I would leave it disconnected to see if solves the rough idle.
The new valve should be an AC Delco or genuine gm if you can find. Some of the after market valves are to generic and create drivability issues.
Which could be as simple as idle speed, or vacuum leaks.
I know you and Rob gave it a thorough vacuum leak check.
Martin may correct. The egr may still be leaking air/exhaust into the intake. A bad egr valve base gasket, warped base, or dirty pintle all could be the source.
Either a new valve, block off plate or manifold w/o egr.
Since you need an emissions test I suggest a new valve. I would leave it disconnected to see if solves the rough idle.
The new valve should be an AC Delco or genuine gm if you can find. Some of the after market valves are to generic and create drivability issues.
Thanks Mike. I will give the EGR system a second look. It has been years and I should check-in on everything.
One question I have for you guys... I just remembered this now... after going for a long drive yesterday, I came home and brought the Blazer into the garage. I wanted to make sure it wasn't arcing anymore. I turned off all the lights and it was totally dark in there. I didn't see any arcing but I saw a flashing "glow" from some of the cylinders. Almost like I could see the spark going off inside the cylinder somehow.
I didn't think it was much of a problem because the plugs and wires are brand new. Does that concern you guys at all?
Not sure what you are seeing. Is this a glow near the exhaust port ? like a heat glow ?
It was an intermittent flashing glow right where the spark plug wire attaches to the spark plug. It was pretty dim. I tried recording a video and my camera couldn't pick it up at all. I saw it on only a handful of cylinders and the flashing seemed random (i.e. it wasn't constant).
Boy, that can't be good. Could be the clips on the end of the plug wires aren't gripping the plugs right. If you had anything coming out of the combustion chamber, you'd have additional problems.
That implies your wire is not tightly connected to the spark plug and is jumping a spark right there.
Are you sure the connector clicked good?
a little dielectric grease in the boots too.
Thanks guys. My to do list right now is to:
- Look over the EGR system as a whole...
- Take it for a long drive... park it in the garage and turn out the lights... identify exactly which cylinders "glow" and double-check the plug wire connection on each of those.
You should check the wires before the test drive. Try and bend the boot at plug tip. It shouldn't move more than a tiny wiggle. If it can bend at all straighten it out and push onto top of plug.
Gonna hot as hell after a long drive.
Gonna hot as hell after a long drive.
This may sound stupid, but what color was the “glow”? Was it blue or orange? Blue would be spark arcing, but orange would be either the exhaust manifold getting hot or if the manifold gasket was compromised it could be flame coming from the port. Though it would be a wicked loud exhaust leak noise too.
Under normal driving I wouldn’t expect to see cast manifolds glowing from heat. Don’t get me wrong they get hot, but normally not hot enough to glow unless it’s under a severe load at lower speeds or excessively lean fuel mixture.
I’d do what Wes mentioned about checking the wire connection at the plugs. Then focus on the egr.
Under normal driving I wouldn’t expect to see cast manifolds glowing from heat. Don’t get me wrong they get hot, but normally not hot enough to glow unless it’s under a severe load at lower speeds or excessively lean fuel mixture.
I’d do what Wes mentioned about checking the wire connection at the plugs. Then focus on the egr.
Definitely not blue. Intermittent yellow-orange flashing. My exhaust manifold gasket(s) are almost certainly compromised... that's something that I never got around to tackling. @Wes Harden was it you who suggested I remove them entirely and skip running a gasket? A long time ago (years), someone on the forum chimed in with that advice and I never got to it.
I'll double-check the connection on all plug wires ASAP.
