'93 S10 Vortec 4.3

[jlsanborn]

Wondering what troubles (engine performance) could come from a smelly cat converter? After warm up the idle is rough and hunts around. It also seems to be lacking power at WOT. Fresh rotor, cap wires and plugs, pcv, air filter, oil and filter. No trouble codes logged in the ECU (12, 12, 12, 12...) The only noteable problem that I can see is that the cat smells eggy.

[wyldman]

The rotten egg,or sulphur smell is caused by the catalytic convertor working overtime due to a rich mixture\unburnt fuel.

I would get a scanner on the vehicle,and take a look at the O2 sensor readings,and the fuel trims.

I would say you have a problem casuing it to run rich,or the computer cannot correctly control the fuel mixture.Some common things (that may not set codes),are a bad O2 sensor,MAP sensor out of calabration,poor exhaust grounding,leaking fuel injectors,or ignition timing.

[jlsanborn]

Thanks for the tips!
Should there be a ground strap on the exhaust somewhere?

[Mowerpan]

Cut the cat off. Lol I did:P

[John DiMartino]

Which 4.3 do you have? If you have the CPI engine VIN code W (8th digit),they are NOTED for bad injectors.I have replaced a lot of them and they acted the same way.You wont always get codes either..If you have the 4.3Z engine they arent prone to this,and I'd look as wyldman suggested.

[TLS]

Is there an exhaust leak prior to the O2 sensor? I've seen that cause a rich mixture.

[FarmerJay]

I'm a new guy here, but I can tell you I had the same problem and changed everything you can imagine trying to fix the problem. You know it turned out to be? The fuel injection spider they call it. It's inside the manifold. It starts to leak raw fuel, and the engine will run rough and smell like no tomorrow. I finally got turned on to what it was by a GM Mechanic I was talking to while out for a beer one night. It was like a 2 hour job, and if I remember right, around $150 for the spider. Let me know how you make out. It would be nice for my ego if my first post fixed a problem for someone right off.

Jay

[AmerilawnOfWisconsin]

I am very curious to see what the fix is for this problem. I have owned 5 different s-10 blazers over the years but had a similar problem with the last one I owned that never got solved. It was a 1994 with the 4.3 vortec v-6. Started to get hard to start and smelled like sulfur and raw gas. I am not a mechanic but really do try to tackle all problems myself. At the time I was swamped with work and decided to save the headache and take it to a mechanic. After several trips back in and many parts thrown at it, problem was not much better! His first try was the fuel pressure regulator that was pouring too much fuel through. Supposedly not avail as a seperate item but he could have mine "rebuilt". Started better after that but still had the sulfur smell and lack of power. Next try was the new GM fuel injector assembly with regulator? Still no better! After a while I didn't want to deal with him "fixing" it anymore and just took it back. It was sold without the problem ever getting fixed and to this day I wonder if it was just something simple. I have yet to find a decent mechanic by me. Let us know what the fix ends up being.

[SIPLOWGUY]

Jay may be right. I remember hearing something like that on a buddies S10.

[John DiMartino]

::D I'm a new guy here, but I can tell you I had the same problem and changed everything you can imagine trying to fix the problem. You know it turned out to be? The fuel injection spider they call it. It's inside the manifold. It starts to leak raw fuel, and the engine will run rough and smell like no tomorrow. I finally got turned on to what it was by a GM Mechanic I was talking to while out for a beer one night. It was like a 2 hour job, and if I remember right, around $150 for the spider. Let me know how you make out. It would be nice for my ego if my first post fixed a problem for someone right off.

Jay
Jay,in my post above I advised him that the injectors go bad very frequently. The Vin code W injector is a CPI unit with 6 tubes,call it a spider or whatever,but its the injector I mentioned almost a yr ago.;) .If you would have found this site/post sooner,you might have gotten fixed faster.:D

[Pickering Snow]

The 4.3 vin w of this vintage has a problem with the fuel pressure regulator leaking instaide the intake , simple to check pull the plastic cover off the top take the tuning vavle off tow screws look on the left side standing over the engine the area will be clean from fuel washing off the carbon, another thing that happens and can start slow is the fuel feed line set under the upper intake cover is plastic and those lines get brittle and leak fuel inside has well.

Smell your oil on the dip stick if bad enough it will cause fuel to dump into crankcase.

The unit termed fuel dist is sold has a assem dont attempt to replace regulator only those kits dont work out well at all.