some sort of internal leak?

blazer do you think the bosch super is fine, if so I will use those it will only be like 6$ us for me to do it, so I might just do it, since the ones I had, had some oil on them...

It's just you will be there replacing one already, you might as well invest the extra 30 minutes and replace them all.

AND DON'T USE BOSCH!!!

USE ACDELCO ONLY.

I run Bosch Supers - no problem. Bosh platinums - problems. *Shrug* But to each their own on this I guess. I am not brand loyal if it works, or works better.

as far as I can tell, their are no more apparent leaks, thanks alot blazerlt. if this doesnt improve my fuel economy, since oil will no longer on my spark plugs, what is my next step of action?

early '90s ignition systems really don't matter what brand of plug you use. 1996 and newer when GM went to OBD2 and newer ignition systems is when you want to stick with AC Delco platinum plugs at 100,000 mile intervals.

early '90s ignition systems really don't matter what brand of plug you use. 1996 and newer when GM went to OBD2 and newer ignition systems is when you want to stick with AC Delco platinum plugs at 100,000 mile intervals.

Poor assumption.

sounds like someone is a little too loyal to AC Delco parts. I install off brand parts in vehicles all day long and never have a problem.

sounds like someone is a little too loyal to AC Delco parts. I install off brand parts in vehicles all day long and never have a problem.

Yea, silly loyal me that likes to inform people to use plugs made for their trucks.

God help me.

There's a close-out sale on GM branded AC-Delco 5w-30 motor oil for $1.50/quart at a local shop over here. Really old stock too. Not that oil goes bad, but - as an example, following your logic to a "T" on this:

This oil is made for our trucks. It carries a dated SH oil standard on the API service logo - but would you put this in your rig? No, you use the best materials at the best cost. In your case, Esso-XD 0w-30 with at least an SL rating I bet. When our cooling systems start to sludge and Dexcool turns brown - do we put back on a new AC/Delco radiator cap? They are the perfect thing made for our truck. But no, we usually upgrade to a stout, Stant replacement because the inherent design of the factory original caps has been proven to not work well at all. Kind of the same difference in a way when I have deviated from using stock parts in an application where it does not make much difference in this case. In newer ignition systems I wouldn't screw around with things too much, and indeed - AC-Delco works best. But the older ignition systems on OBD-1.5 and earlier will get along just fine as long as the part is gapped properly, has a resistor core, has required thread depth and heat range matched. Denso makes plugs as does NGK, Champion, Autolite Copper #25's and Bosch Super Copper reisiter cores that all work excellently in 95 pre OBD-II and earlier. But oddly enough, this is not the case in 96-on for some reason.

Could it be that they are using an "ion sense" pre-charge ignition system like many GM-built Isuzu's are using? Anything that messes with that calibrated system will cause miss-fire and stumbling idle pretty quickly. It's a litle too sensitive, IMO. I merely recommended that one *try* the Bosch Super plugs because of their shorter insulator length though they are a perfect match for the 95 4.3 iron block V-6 in every other respect. It will save the poor person who undertakes a plug job on their own a few knuckles and the experience of cracking off the insulator on a plug or two. I know I broke them a few times getting them out until switching to Supers. No problems and well over 12,000/1 year on my current set of them in my experience thus far. Besides, if the truck does not like them, they are just $0.85 a piece if you buy a box of them. So please try to understand my stance/opinion just a little on this one. They're cheap, easier to work with, and last about what one would expect - about 2 years or so.

Edit: I have a pre-OBD-II '95 Blazer with an older style ignition system where the plug wires stick straight out of the top of the distributor towers. And it loves the Bosch Supers. Before I swapped to them, it was running 1 AC-Delco plug (in the #3 plug hole, go figure) and the other 5 were #25 Autolite Copper cores. No difference I could tell when swapping them all for new Bosch Supers. However, the Bosch Platinums and any of the +2/+3/+4 varieties should be avoided. The electrode tabs for some reason get hammered off of them in our engines and they float loose inside the cylinder causing mucho damage.

my question is still un answered, if this doesnt help with the fuel economy what will?

what kind of milage are you getting?
are you getting any O2 sensor codes?
are you fouling any plugs?
are you still having the idle problem?
is the motor TBI or CPI?

its a cpi motor, and what is meant by fouling? previously I had an internal oil leak, but I believe that is fixed now. I was getting about 12 mpg on the road and about 14 mpg on the highway...

the idling has also gotten way better

are the ac delco rapid fire plugs good?

any suggestions on the ac delco rapid fire plugs?

There's a close-out sale on GM branded AC-Delco 5w-30 motor oil for $1.50/quart at a local shop over here. Really old stock too. Not that oil goes bad, but - as an example, following your logic to a "T" on this:

This oil is made for our trucks. It carries a dated SH oil standard on the API service logo - but would you put this in your rig? No, you use the best materials at the best cost. In your case, Esso-XD 0w-30 with at least an SL rating I bet. When our cooling systems start to sludge and Dexcool turns brown - do we put back on a new AC/Delco radiator cap? They are the perfect thing made for our truck. But no, we usually upgrade to a stout, Stant replacement because the inherent design of the factory original caps has been proven to not work well at all. Kind of the same difference in a way when I have deviated from using stock parts in an application where it does not make much difference in this case. In newer ignition systems I wouldn't screw around with things too much, and indeed - AC-Delco works best. But the older ignition systems on OBD-1.5 and earlier will get along just fine as long as the part is gapped properly, has a resistor core, has required thread depth and heat range matched. Denso makes plugs as does NGK, Champion, Autolite Copper #25's and Bosch Super Copper reisiter cores that all work excellently in 95 pre OBD-II and earlier. But oddly enough, this is not the case in 96-on for some reason.

Could it be that they are using an "ion sense" pre-charge ignition system like many GM-built Isuzu's are using? Anything that messes with that calibrated system will cause miss-fire and stumbling idle pretty quickly. It's a litle too sensitive, IMO. I merely recommended that one *try* the Bosch Super plugs because of their shorter insulator length though they are a perfect match for the 95 4.3 iron block V-6 in every other respect. It will save the poor person who undertakes a plug job on their own a few knuckles and the experience of cracking off the insulator on a plug or two. I know I broke them a few times getting them out until switching to Supers. No problems and well over 12,000/1 year on my current set of them in my experience thus far. Besides, if the truck does not like them, they are just $0.85 a piece if you buy a box of them. So please try to understand my stance/opinion just a little on this one. They're cheap, easier to work with, and last about what one would expect - about 2 years or so.

Edit: I have a pre-OBD-II '95 Blazer with an older style ignition system where the plug wires stick straight out of the top of the distributor towers. And it loves the Bosch Supers. Before I swapped to them, it was running 1 AC-Delco plug (in the #3 plug hole, go figure) and the other 5 were #25 Autolite Copper cores. No difference I could tell when swapping them all for new Bosch Supers. However, the Bosch Platinums and any of the +2/+3/+4 varieties should be avoided. The electrode tabs for some reason get hammered off of them in our engines and they float loose inside the cylinder causing mucho damage.


I really don't get why you are saying all that when all I was stating is that the AC Delco plugs have yet to fail in ANY application when used in our trucks.

I recommend what works, not what possibly could work.

Why you are bringing up old oil and defective rad caps and dexcool is beyond me.

any suggestions on the ac delco rapid fire plugs?

They are good, but standard AC Delco plugs will work fine in your truck.

I have rapidfires in my truck and to be honest, I can't really feel any difference.

I got them for cheap off of ebay and that was the only reason I used them.

if I decided to use them, would I need to change my wires? and also this did not improve my fuel economy... the leak is indeed gone, but I still only get like 10 miles per gallon on the road and maybe like 14 on the highway, any suggestions..

ps, blazerlt, you have been a real help man, I started out not knowing anything, and so far everything you have told me has been correct. and Now I can do alot of my own repairs... thanks!

Reset your computer by pulling the negative battery termainla for an hour.

Let the engine relearn the proper air/fuel mixture.

Also, with the new plugs you shouldn't need new wires unless if they are really old or are arcing.

I have done that already...

Just to recap, how many miles are on it and have you ever replaced the O2 sensor?

i have 112k miles, and I replaced a sensor, I dont know if it was the 02 sensor. It was a sensor that checks what temperature the car is at, and then delivers fuel accordingly, it was located in the mid area behind the serpintine belt

come to think of it, it may have been the coolant temperature sensor that I replaced...

also, if the O2 sensor is bad, wouldnt a check engine light come on?

I recommend what works, not what possibly could work.

Why you are bringing up old oil and defective rad caps and dexcool is beyond me.

I am merely stating the same thing. I am recommending something that works, and is easier to get in than the longer AC-Delco stock/Rapidfire replacements. The reason why I bring up old oil and Dexcool + Radiator caps is for contrast. These things are specified to work in our trucks too, but newer formulations of oils are better, as are revised formulations of Dexcool which has proven to be slightly more resistant to air exposure; and ditching the radiator caps for Stant units over factory original "Made for our trucks" stuff. My argument really is, if a plug meets thread depth, width, heat range and electrical characteristics, it will be a good match and Bosch Supers meet that criteria easily in a much smaller package that's so much easier to maneuver about without having to drop the steering column or go through any real contortions to get into place. *Shrug* But at this point I will stick to using them if nobodsy else does. They work. Plain and simple. I'll shut my mouth and agree to disagree on this point and that will be that I guess. :dunno:

ok, blazerlt, I have replaced the coolant temperature sensor, fixed the leaking valve covers, check for more oil on the spark plugs, no more is there. I reset the computer, and replaced the fuel filter, changed the oil , changed the oil filter, and air filter. Even reset the computer... I have 113k miles on my truck, and I have only had the truck for a year, and I never changed the 02 sensors. I do not get a check engine light.


I am beggining to think my fuel injection is bad. I think my plugs are fouling up, and I detect a slight smell of gasoline when my truck has been running for a while.

What other things could be causing poor fuel economy.

Also, I disconnected the hoses that go to the heater core, to try to stop the waterfall that I have on the floor of the driver and passanger sides, but it looks like some water or coolant is still there. Maybe It hasnt dried up yet, I dunno...

Sounds like you are in deep into the truck! I would hazard a stab and spin the mighty wheel of possibilities... *clickitey-click-click....click* PCV vale? They're $3 - swapping it out may improve idle quality and stop ingestion of oil to foul the plugs. Have you looked into replacing that yet?

just replaced it last week before I replaced the plugs...

also My idling has pretty much gone back to normal after repairing the valve cover gaskets

Well, then get your #30 Torx wrench out and pull off the plastic Vortec plate atop of the engine. Use a #15 to remove the round looking plug right in the front of the upper plenum, this is your IMTV. Peer inside with a flashlight and get a good sniff too. If there is fuel pooling in there, well, your CPI may be suspect again. Be sure to put the IMTV back the same way it came out. :)

ok, I am gonna have to do it in the morning, it is already dark out... what do you expect may be my leak inside the car, if I disconnected the hose leading to the heater core?

The heater core. That is some work to get to - the entire dash has to come apart and be unbolted to rotate back on lower hinges so you may reach up and behind it to get anywhere near the core.

just did the heater core, it was seriously a huge pain in the ass...

I believe heater core can be done on 1st gen S-10s without removing the dash. Here is a link.

http://www.sytyarchives.com/howto/viewarticle.php?article_name=heater_core.php&dir=climate_controls

ok, I have the new heater core installed, I forgot, because I have not been using my ac, but for some reason cold air blows out of the floor and window vents, but not out of the vents that are pointed at your chest... I checked the pipe that connects to the fixture in which the heater core is installed, and everything is reconnected. but for some reason no air will come out of those vents. for some reason the air only works on the highest setting, and not on any lower ones...