1994 S10 blazer idling rough

Curious as to what could be causing a very rough idle on this vehicle. I've replaced the spark plugs and wires (they were all original 95,000 miles on them) They are correctly gapped, I replaced the fuel filter, I have pressure on the fuel line for sure. I took off the distributor cap, and the points were worn, and had a white powder built up on them... Not sure what it came from, but almost like you get on battery terminals. I don't think it was from all the salt on the roads (I sure wasn't going to taste it to find out)

It is idling so rough, it makes the entire blazer shake (which doesn't take much, but still...). It seems like it isn't firing on one or more cylinders, because it almost seems like I can smell the unburnt gas out the exhaust and the backfires. It has plenty of power as soon as you press on the gas, and doesn't seem to have any other problems, just at idle. The service engine soon light comes on occasionally while I am driving, but it goes out and when I check for stored codes, there aren't any...

Any ideas on what I could check before I pry open the wallet?

Reply to
Tux in a Ram
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egr or distributor

~KJ~

Reply to
KJ

replace your cap and rotor and all should be well.

-Bret

Reply to
Bret Chase

Replace cap and rotor. I had a 90 Blazer that I had to replace cap and rotor at least once a year because it had the buildup and was worn also but I put a lot of miles on in a year.

Reply to
Daryl

Reply to
Mike Levy
50 bucks says your EGR is sticking open with a hunk of carbon. A VERY common problem. Causes a lopey idle and hunting, will run fine as soon as your going down the road but will not idle.

The white powder in the cap is what is left when the spark ionizes the air as it fires causing the aluminum connectors to corrode.Then any moisture also leaves behind any minerals on the posts as well.

On the EGR just remove the air intake duct (two clamps and the hold down bolt, one wire connection near the throttle body) Then the EGR connector and one 13MM nut and a 10 MM bolt on the other side. Pull it out through the hole between the water outlet and the Throttle body. Tip the front up about 90 degrees while turning it just a bit and it will come out. Push the pintle up and clean out the carbon. There is a gasket available that has a screen to stop this from happening again.

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contact them to see where your closest placeis.

Reply to
Steve W.

Reply to
reitze

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