Chevy Astro and GMC Safari Forum banner

Iffy spark plug

3K views 35 replies 12 participants last post by  MrBob 
#1 ·
Some of the plugs coming out of my van look like this. I had a tech tell me they are oil fouled so I am installing anti foul shields on the ones that look like this.

Another tech told me its fine & just show the exhaust valve side of the plug.

Going through everything with a fine toothed comb to try to fix misfire issue.

Any opinions?
 

Attachments

See less See more
1
#5 ·
I had an '87 1/2 ton van w/ a 305 that used to oil foul 2 plugs consistently. I bought the next step hotter plug for those cylinders and that solved my issue.
In your case I'd be checking the gap when you install new plugs and maybe over or under gapping, possibly shorten the electrode. I've heard of cutting them back to the center of the core to expose more of the spark.
 
#7 ·
Man, it seems like you're all over the place with this thing. Best thing to do is keep it simple and not complicate things by just replacing a bunch of stuff that may have an unknown knock-on effect on what you're trying to fix. Seems like you need to get back to a baseline, as everyone else mentioned, go back to OE/Delco plugs without any of the other "add-on remedies". I'm not sure what you magic those expensive "special" plugs are going to achieve...

Also, perhaps find a knowledgeable independent repair shop with a good reputation rather than the Goodyear and Firestone type places.

Best of luck, I hope you can get it sorted.
 
#8 ·
Yeah, corsemoto, that would be great but they all refused to take it on since I have done everything they would do.

I have a couple guys at a taxi shop that are helping me and will try another local guy Monday.
'
For the first time today I cruise controlled it at 60mph and it DIDNT MISFIRE!

I am on the right path. Only the idle is a mess now.
 
#11 ·
Anti-foulers are like leak stop...they didn't come standard with the engine, and are meant only

as a stop gap measure until you can really fix the real problem. Eh !

Uncle Bob
 
#16 ·
So today was in downtown Brooklyn and saw a 92 astro I see every week when I go there for church. I found the owner who worked at Brooklyn law school. Older Mexican gentleman. I could tell he knew his van. It had 250k miles.

His suggestion was to swap coil and PCV valve (like my mentors on here said too).

These vans are like bikes because of the cult following they produce. Gotta love that.
 
#18 ·
So how do I tell the temperature of a spark plug and chose one to not foul (or whatever happened to these?)

I got some NGK's but am trying to figure temp range compared to the autolites.

Then NGKs are marked UR5GP & 3547. The autolites only say 25.
 
#19 ·
chevymaher said:
That is why i got the truck after the first engine wen't out. I am pissed if something happens. I just park it a week and cool off. Then look at it.
I parked mine once for several months. Not working on a car for a while gives you a chance to actually get your hands clean. Well, they don't really "get clean" they just shed the dirty skin and grow new.

Lump
 
#20 ·
Lumpy said:
I parked mine once for several months. Not working on a car for a while gives you a chance to actually get your hands clean. Well, they don't really "get clean" they just shed the dirty skin and grow new.

Lump
I just find you do better work and make better decisions if you had a chance to mull it over. No big rush.

Object is to solve the problem so it is over for 20 years. Not rush so it is running to drive.

And miss things like a "Cracked Head" which will cause more grief in the future LOL. Not mentioning any names RANDY. It is apart take your time and check everything. Not just assume it is good because that wasn't the problem "YET".

Case in point. It sat longer before I even looked at it this time. Than it took to rebuild and put together last time. Tired of screwing with the motor the hardest part on this thing LOL.

Time to move on and do much easier maintenance issues.
 
#21 ·
chevymaher said:
...you do better work and make better decisions if you had a chance to mull it over. No big rush.
And SAFER. Same with working late in the day. "I'll just hurry and get this thing on before the sun sets"

chevymaher said:
Object is to solve the problem so it is over for 20 years. Not rush so it is running to drive.
Everyone should re-read that.

I think that's the difference between DIY and pay a shop. When your car is not running, and you take it to a shop, if they give you a choice of $300 or $900 to fix it, which do you choose? You choose the lower price because you're emotionally upset, tired, NEED to get back on the road etc.

But the $300 fix is the "rush so it is running to drive" fix. If you DIY'd it, you'd get the "20 year $900 fix" but it would only cost you $300 to do yourself. Plus you'd end up with the tools, knowledge and most important confidence to fix other stuff in the future.

"Oh My God! I'm stuck in Duluth with a busted Weinstein valve and they want $1200 to get me back on the road"

vs

"I replaced my aging Weinstein valve bracket that was cracked. Cost me $60 from RockAuto and I had to buy an 11.4mm coarse Torx socket that cost $9"

Lump
 
#22 ·
I fully agree with you in principal lump. But not everyone can stay hundreds of miles from home indefinitely without major problems in the rest of you life.

Not to mention a place to wrench and the lost time from you only vacation of the year with your family.

Its not always black and white.

Now that its home and life resumes, I can take the DIY approach. My driveway, my tools and this forum.
 
#23 ·
smokinjoe said:
I fully agree with you in principal lump. But not everyone can stay hundreds of miles from home indefinitely without major problems in the rest of you life.

Not to mention a place to wrench and the lost time from you only vacation of the year with your family.

Its not always black and white.

Now that its home and life resumes, I can take the DIY approach. My driveway, my tools and this forum.
I'm not recommending anyone stay hundreds of miles from home indefinitely.

I'm suggesting that a $900 repair bill while you're on vacation is a problem. A $300 repair bill while you're on vacation is much less of a problem. A $100 maintenance bill 3 weeks before you left would be even less of a problem. You stop to eat, sleep, fuel up, feed the ducks. No different to stop to change a fuel filter, unless you allow your mind to turn it into some kind of emotional trauma.

Time away from your family while on vacation - If your car's broke, your car's broke. I guess you could sit in the hotel room, with your family, and cry about the expensive repair and how you don't get to visit any of the vacation spots you've planned on.

Black and white - Actually, it IS black and white. Car parts either work or they don't. It's the human emotion factor that interjects the grey areas. Repairing cars is a flow chart. You look in the book and it says "TEST THIS - IF THE ANSWER IS A, GO HERE. IF THE ANSWER IS B STOP". Nowhere in any repair manual does it say "try replacing a bunch of parts just to see if maybe that's the problem". You diagnose what's wrong, then repair THAT part.

I'm glad to hear that you're now interested in the DIY approach. That means taking ownership of what can be maintained and repaired. Because at the end of the day, dispite all the worrying and the dozens of threads on "Maybe it's this part" and the thousands of dollars spent...Your van isn't working properly from the method you've been following.

Life "resumes" - I'm not sure that I understand that philosophy. Unless you die and are resuscitated, life doesn't "resume". I'm the same guy whether I'm home or away. Maybe if I viewed things like "OK I'm going on vacation, nothing can go wrong" then I'd understand all that. But I don't.

If you're not in control of your universe, then you are at the mercy of someone else who is. Not someTHING else, someONE else.

Lump
 
#24 ·
smokinjoe said:
So how do I tell the temperature of a spark plug and chose one to not foul (or whatever happened to these?)

I got some NGK's but am trying to figure temp range compared to the autolites.

Then NGKs are marked UR5GP & 3547. The autolites only say 25.
Those plugs were not oil fouled so the hotter plug won't help. I believe that burn may have been because of the gap or maybe the plug was dropped, insulator broken.
In any case to find a hotter plug you need to find the manufacturers code. Google for it, "spark plug temperature range" maybe? I don't know. I don't remember the details on how I got it as when I did this we had no interwebs, could have been trial and error or maybe I was told. Sorry,,,
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top