S10 4.3l won't accelerate

[RIDE-RED 350r]

Glad you got it sorted out!!

 

[paragonbuilder]

Glad you got it sorted out!!

Thanks bro!

 

[Brush Ape]

Onced again the EPA sticks it right square up a guy's ass...

 

[huskihl]

And just because you can buy the fuel pump without the gauge sending unit for $25, dont. Their junk. All 4 of them lol. I'd do like super3 said and look for an ac delco or delphi with the sending unit. You'll need it before long anyway

 

[ABarrick]

Glad you got it figured out.

I run a auto repair shop for a living and the area I live in is GM country. Ive worked on a lot of S10s. Cat plugging is common on them. Some will not throw a code without the cat, some will. Depends how efficiently it's burning the fuel. Spark plug non-foulers are usually a waste of time. I've never had one work that wouldn't have passed the cat monitor without it anyway.
Most vehicles that come in with a P0420(catalyst efficiency below threshold) are not cat problems, they're combustion efficiency problems. Not all but many. Thus the reason they plug cats. The CPI vortec engines run great when everything is perfect but as parts wear they still run ok to you but the PCM overcompensates and tends to run them rich. The catalyst is sized to "process" a certain amount of hydrocarbons. Once that limit is exceeded consistently it begins to start plugging the tiny passages. As they plug up, flow is restricted to less and less passages and it gets to the point where it creates an excessive restriction which creates more heat buildup and eventually to the point where the monolith melts down and restricts the exhaust. This is normal and will happen over time to a point but gets accelerated on a vehicle that burns a lot of oil or was run for a prolonged period of time with a misfire or poor fuel, etc. Raw fuel/oil does not burn off cleanly and plugs up the cat. This can happen after the truck is shut off. The cat is still working until the chemical reaction stops. So in your case, your cat was probably right on the edge of failure, you ran the truck and loaded it up with fuel and after you shut it off, it's still cooking away and plugged itself.

The plugs are sooty because of a lack of air as well as trimming too much fuel. If it can't get air out, it can't get air in. The PCM cannot "see" a mechanical problem. The MAP and MAF readings would have been off but that won't set a code for quite a while til the PCM recognizes a consistent residence on that range. I'd change the plugs regardless. Once a plug is sooted, it's never the same. It could have been the plugs that started the whole chain reaction anyway.

In summation, gut the darn cat and slap some good plugs in it (AC or NGK) and run it.

AJ

 

[DELETED (Struggle)]

Is there a way to test for intake gasket?

More than likely at that mileage it has been replaced already. If not it would be a must do repair as everyone I have ever done the plastic breaks/cracks around the ports from heat and it pushes out and leaks. Can cause a drive ability issues.

There is also two different levels of gaskets for it. THe more expensive kit has metal embossed gaskets with seals instead of the plastic molded style.

Sounds like you have you fix now though.

I have worked several times on the 4.3s in blazers and S10 and there is very little room to work with. They are a good engine though.


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[paragonbuilder]

Picked up a stainless cat back exhaust for $190. Walbro fuel pump is on its way. Gonna pull the bed this morning.

 

[rjames]

When you replaced the injection, did you buy the mpfi upgrade kit or use the stock style poppet injector spider?

I have a 97 full size and I've had every issue and turned just about every nut bolt and screw on my truck over the years.
One of the most misdiagnosed and overlooked sensors is the cts (coolant temp sensor). When they go, the engine is constantly in warm up mode. Make damn sure your cts is working properly, especially after replacing a cat.
Really easy to check, use your ohm meter and check it cold, then when it's warm.
Just pull the connector and check ohms. Cold should be high, like 7-9000, when up to temp, should be low around 170-200.

temp

Picked up a stainless cat back exhaust for $190. Walbro fuel pump is on its way. Gonna pull the bed this morning.

 

[paragonbuilder]

When you replaced the injection, did you buy the mpfi upgrade kit or use the stock style poppet injector spider?

I have a 97 full size and I've had every issue and turned just about every nut bolt and screw on my truck over the years.
One of the most misdiagnosed and overlooked sensors is the cts (coolant temp sensor). When they go, the engine is constantly in warm up mode. Make damn sure your cts is working properly, especially after replacing a cat.
Really easy to check, use your ohm meter and check it cold, then when it's warm.
Just pull the connector and check ohms. Cold should be high, like 7-9000, when up to temp, should be low around 170-200.

temp

I got the upgrade kit. Damn truck ran the same. Pissed me off...
It was probably the stuffed up cats though.
Where is that sensor? It's not the one that's for the gauge, correct?

 

[paragonbuilder]

It's a little crusty

 

[paragonbuilder]

What is that black box behind the tank. It's got fuel lines in it???

 

[94BULLITT]

What is that black box behind the tank. It's got fuel lines in it???

It is the vapor canister.

 

[paragonbuilder]

Freakin exhaust is actually in good shape. I probably didn't need the kit...
Oh well. I think my FILs is shot. I'll give it to him.

 

[rjames]

No sir, that one is in the head, driver side and it's a sender, not a sensor. The sensor (often overlooked) should be right by the t stat housing, screwed into the manifold. The sensor changes the fuel mapping as the coolant temp rises.
Glad you got the mpfi, much much better injection.

I got the upgrade kit. Damn truck ran the same. Pissed me off...
It was probably the stuffed up cats though.
Where is that sensor? It's not the one that's for the gauge, correct?

 

[junkman]

It's a little crusty

Weird seeing a truck that new with a rusty frame .They still look pretty new when pull the beds off here .

 

[Stihlbro]

Weird seeing a truck that new with a rusty frame .They still look pretty new when pull the beds off here .

I would wire brush the frame and use the rust convertor. It is available in aerosol cans or by the quart and brush on. Walmart 96 cent black paint and you can buy your self a few more years.

 

[paragonbuilder]

Weird seeing a truck that new with a rusty frame .They still look pretty new when pull the beds off here .

It's the salt. Most trucks 2008 and older here have bed rot already. Sucks

 

[paragonbuilder]

I would wire brush the frame and use the rust convertor. It is available in aerosol cans or by the quart and brush on. Walmart 96 cent black paint and you can buy your self a few more years.

I was thinking of using Por15 .
Only need to get the loose rust off, a lot less work. It's about $100 a gallon.

 

[paragonbuilder]

No sir, that one is in the head, driver side and it's a sender, not a sensor. The sensor (often overlooked) should be right by the t stat housing, screwed into the manifold. The sensor changes the fuel mapping as the coolant temp rises.
Glad you got the mpfi, much much better injection.

Great! Easy to get at. I'll check it out.

 

[Stihlbro]

We're on the same sheet of music, rust convertor is less than 20 dollars a quart. 5 cans of paint is less than 6 dollars. End result is the same.