[crushme99]

Hi all,

I just purchased an 88 4.3 S10 Blazer with 205k miles on it. I've driven her for a week (probably 500 miles). It takes a couple seconds to turn over but starts up.

First couple days, engine ran perfectly. Perfect at idle, perfect at high speeds. No hestitation.

Yesterday during the day, at a traffic light, it would idle fine but then every 10 seconds or so, the idle would drop and it felt like it was going to stall.

Then in the evening and again this morning, while running for a while, at higher speeds (50-70), there seems to be a hesitation, like a sputtering. Idle seems consistent. When I give it a little gas and when it downshifts, its fine. Then after it shifts back up and runs consistently again. It does it again for a couple seconds.

What could this be? Spark plugs? Injector needs cleaning?

If so, is it hard to change the plugs on her, and where could I find instructions..
What kind of injector cleaner works the best??

Thanks all!!!!
Chris

 

[BlazerFRS]

I would take off your distributer cap and look for condensation/corrosion. If either is present that can cause hesitation/sputtering.
Only about $20 to replace a car and rotor, so it's worth a shot anyway.

Seeing as it has 205000 mi on it you will probably want to change the spark plugs too; unless the previous owner did it in the last 60,000 mi or so.

If you're not sure when they were replaced you can remove one and look at it. if the bottom looks corroded/worn or is the gap is wrong (you will need a gap measureing tool from an auto parts store, pretty cheap) you should replace them and the wires as well.
Me, I go with the OE ACDelco spark plugs, but I've hear of others using different brands.

To find the plugs just follow the wires from the distributer cap, these will lead to the plugs. You will need a special socket for your ratchet to screw them out, should be avalible anywhere. The real issue with this job is space. There's not alot of room in there for a socket and rachet, so you'll have to get creative at times to get them out. It took me an average of one hour (yes one hour) per plug to remove, replace, and run the new wire.

It's time consuming, but not really hard to do.

Good luck!

 

[rlith]

Check the usual suspects, cap, rotor, wires, fuel filter.... But I'm more interested in your EGR... Sounds like it's clogged... Pull the EGR, clean it with carb cleaner and a stiff wire brush...Make sure the pintle is freely moving (use the eraser end of a pencil to move it) Clean the EGR port on the manifold itself and run some seafoam through the engine)

 

[joshuaga]

Well i did some checking late last night and checked the egr valve. Its working great. The plugs need to be changed so ill goto that next. I talked to a tech friend and he said that if any of the sensors were bad it would throw a code. I have no codes now. Also what are the possibilities that there is an issue with the timing? Im going to try to check it tonight but im not sure if i can tell anything without it running. Thank you all so much for the input!

 

[nickelsun692]

Since you don't know the maintenance history, I would definitely replace the inline fuel filter. Next idea is that the fuel pump and or guage could be fauty. Any performance difference with a FULL fuel tank? Be carefull, but check fuel pump pressure when you replace the filter. Have a trusted friend briefly turn engine over. Good stream should indicate that the pump is ok. Don't do this in a garage, pull distributor wire, be ready to run like hell!!