Hello all. My name is David. I just purchased a 1995 S10 Blazer. I like the truck alot, but I am having problems with it. I have spent many hours on the computer looking for things/answers. So, now here I am. Here's what I got. It had a really rough idle and poor gas mileage. It would surge and I would have a hard time braking. So I took it to Firestone. Thats were I've had my Civic serviced, if I didn't do it. They did really nothing. But charged me 300 bucks. LOL... But, I went and bought a scanner. I couldn't get a reading. So I took it to GM/Chevy dealership and they couldn't get one either. So they said my ECM is bad. And my EGR was too. So I cleaned my EGR really well, and put a TOMOCO? Gasket on it and ran Seafoam thru itonce. I also changed my plugs and plug wires. But, lots of smoke came out of the exhaust and I started getting a really good idle and better gas mileage. Almost 17mpg. And no SES light. The truck has been driven almost 2 weeks now and both gas and idle are getting bad again.

Now, after all that, if the ECM is bad, could the tuck still be driven on a daily basis? I checked my fuses. They are good. I don't know what I should do here. Ihad a Honda Civic and I worked on it from time to time, so I can work on the truck. But, I only know 4 cylinder and foreign cars. So, I am kind of lost. Oh, I did change out my PCV. And I bought a MAP sensor, but haven't installed it yet. I was told that might help.?

 

Just because the egr valve got clogged doesn't mean it needs to be replaced, first of all. It's not super easy to take off, but doable with a flex joint, an extension and a 10mm (I think) socket. If it's getting clogged, then there are some other things going on - it can get reclogged because there's alot of carbon buildup in the flow system going to the valve and you'll have to reclean it. Or you can try a wire screen gasket (kleenscreen). You can check out my DIY post on the fuel pressure regulator, at the end of which there are some notes about cleaning some of the vents that go to the egr valve. This may help. You could also try cleaning some of the sensors on the top of the plenum too. YOu may need to clean or replace your O2 sensors.

 

Well, the EGR valve really wasnt that hard. Until I screwed up the tread pattern by putting the bolt in sideways. But that was fixed. And I put in a kleenscreen, as Autozone calls them. But, I got what they got. Just paid alil more, unfortunately. But, I put some more seafoam in it last night and again, alot of smoke. So I know carbon is building up. Heck, I can smell it at a red light, when my ac is running. Or when I get out the car. I have been thinking about my catylictic converter. Could it be plugged as well? Is there anyway it can be checked without taking it off the vehicle? And what about the ECM? If it's bad, can the truck still be driven? And I've been looking to replace the O2 sensors. But, somewhere on here, I read that not to get the Bosch, but get AC Delcos? Something like Bosch don't work as well or something. I can't find the thread. But I did research on here before I posted.

And thanks for any help ahead of time with this truck. I know some of this has been posted many times, and I will try to not post whats already been posted. Sorry if some does...

 

Stick with the AC/Delco O2 sensors.

 

Yeah, I figured it would be as much. I am having somewhat the same problem, and I actually had to pull of the entire intake off one of my trucks to clean it out for good. The passage that carries the exhaust gas back to the intake goes through the bottom of the lower intake manifold and there is basically no way to clean it without taking off the damn thing = PITA. However, I have another truck (also a 95, incidentally) that had the problem and it didn't come back after seafoaming it a few times. I would try going this route first.

Unfortunately you might have a dead cat and no there's no way to absolutely check it on the car, at least that I've ever heard of. You can always try to rattle it and if you heard stuff clunking around (or especially if it just does so when the car is running) then you're pretty much guaranteed to have a bad one. I had to replace each of mine, and the O2 sensors as well. However, I used bosch sensors and had no problems at all. I got them at Pepboys and they are lifetime warranted, so if they were to die (which hasn't happened in over a year) they would be free to replace and obviously they are super easy to change. On the other hand, the delcos might be better, but they are hella more expensive. And there are 2 of them, so, take your pick.

As for the ECM, I doubt that has anything to do with it. If it were bad, you probably couldn't drive the truck at all, not by choice, but that it just wouldn't run because the drivetrain is electronically controlled in alot of ways. Autozone will test ECM's for free. It could just be the connector, not the ECM.

I do suggest this if you are seafoaming alot, and this is slightly a pain - get a spare set of cheap spark plugs to install when you are going to do the decarbonizing. That process will spoil your plugs and it might pay to get some decent ones like Delco RapidFires for actually driving use, but don't ruin them by smothering them in carbon goo then running the vehicle. You can more easily get to the middle drivers side plug by using a T-handled spark plug wrench (by Great Neck - available on both Amazon.com and at any Autozone for $5) to get it out very easily. Just cut off the retaining spring first.

Remember, it's not that carbon is building up so much; what you are actually doing is getting rid of it. Once you've gotten most of it, it might be a long time before the buildup would present a problem again (maybe, of course). I think the reason for this is because there might be a problem with the valve guide seals going out on these vehicles (95's/CPI engines at least) but I haven't conclusively isolated that yet. I'm about to change mine on the one vehicle that has more severe problems and we'll see if it helps. They are not too hard to change.

PS - if you are going to post on here very much, you need to put down your vehicle details in your sig, per forum rules.

 

ok, I didn't read the rules, like a dummy. But I will post the info. And as for spark plugs, I got the very best, rather the most expensive. I think they are Bosch+4 or something. I used NGK's for my civic that I have. And they have lasted very well to the abuse that i've put it through. But I did forget about the plugs needing to be changed. And I did just change them. So does that mean they are no good now because I did use the Seafoam? But, something is causeing all this carbon build up. I've read, and I still have the stickie from another forum, that the problem is a software issue on the vehicle. Here is the site for referrence:
http://www.topix.com/forum/autos/che...LP71GP38P51IOV

When I took my truck to GM/Chevy, they looked at me like a retard. Said there's nothing like this, and that this isn't my prob. And I did try to get Autozone/Advanced to check for codes, and they can't get anything either. So, can someone give me some suggestions? Should I just go ahead and change out all the O2 sensors and get a new cat? I'm almost ready to trade it in for something else. And I haven't had it very long. Is this stuff going to haunt me as long as I have the vehicle?

 

If you want to sell an otherwise good 95 blazer with those problems without trying to change the O2 plugs and the cat first, I'm in the market!

Ditch those bosch plugs - they actually are pretty worthless. Sorry to be the one to tell ya. ACDelco plugs are really the way to go in these trucks, and many people recommend using platinums. Autolites are also considered good. I use the Delco RapidFires (which are platinum plugs) and I could really feel the difference once I put them in, especially when accelerating hard.

If the exhaust sounds like it's chugging or it's spewing black stuff, chances are also good the cat is bad.

Just because they say they've never heard of it at the dealer doesn't mean its not out there. Some dealers are just lazy, ... etc. You can always call another dealer and give them some more specific details (service bulletin number) then they can look it up. I did nothing else but clean out my EGR and change O2 sensors on one truck and that fixed the problem completely, as I said before. I'm not sure how a different programming is going to fix a big chunk(s) of carbon stuck in the EGR, but I'm not an expert.

To change the O2 sensors you will need a 7/8 (I'm pretty sure) wrench (or a slightly smaller metric equivalent) and some penetrating oil. You can check the size of the wrench by checking the size on a new sensor at a store.

 

Ok. I will go see what the O2 sensors would cost. And the cat shouldn't be no more than 200 bucks. Hopefully. I will look at my extra spark plugs and see what they are. But, there are 4 O2 sensors right? 2 in the engine bay and 2 at the cat. I would assume all 4 would have to be changed. I did get a book from Autozone, which these books are hard to find where I live. But any ideas with the ECM? Why I can't pull codes? If I could pull a code, I could fix this truck and that would be that. But, I can't, neither can Autozone/Advanced, or Gm/Chevy.