Here's the deal. 86 S10 Blazer, 2.8 TBI Manual.

Thereare a bunch of little things that i am confused about, and would like to know if anyone has any experience with any of the problems that i have. here goes...

1. Injectors are dripping. The back one on the right is really bad about it. I run STP through regularly (the black bottle), so i doubt its dirty. It could be damaged or something, but im not sure.

2. At the bottom of second gear, i get this weird sensation in the tranny. Not like its grinding or wanting to come out of gear, it just sounds like someone is running a plastic fork across concrete or something.

3. The fuel gauge. It used to work, but one day i was downshifting and had to slam on brakes, but for some reason i felt like i had to have it in gear first so i dumped the clutch and the truck bucked really hard. After that happenedthe 1/4 mark is equal to a full tank.

4. The coolant temp gauge is fishy too. No matter how long i drive or how hard i drive it, it never goes too far above the very first line. Maybe its a thermostat making it run that cold, or the gauge is out. Im not sure.

5.Oil pressure gauge. It goes all over the place, but within a range of like 5 to 10 PSI at idle. When i get on it it levels out. Also on cold starts it says i have 80 PSI of oil pressure. Normal?

6. I turned on the rear defrost one day and i heard a pop. I got out and looked at the wires to the back glass and both were completely severed, but not cleanly like they had been cut. Hasn't worked since.

7. Sitting at idle, if i give it a specified amount of gas the rpms rise, then fall back about 50 to 100 and sits there. This is really annoying because if im in first and am holding the accelerator at a certain place the truck surges and trips over itself really bad.

8. Check engine light. It comes on for like 2 minutes on hot starts then goes away. It also will sometimes come on randomly but if i floor it through a gear it turns right off. This is very confusing for me.

9. On said hot starts, the truck cranks really strong, thenimmediately after the first like half second of it runningthe rpms fall back to stall speed andit sounds like i have cams put in. I give it some gas and it clears up.

I replaced the fuel filter, standard tune up stuff is about 20k miles old, air filter was replaced at last oil change about 600 miles ago, and i drive it like an old man.The truck is completely stock, except that i have the aircleaner cover flipped. (This has been like this for a while,helps it run better.)Whats up with this stuff?

 

The first thing that I would address is the dripping injectors. There becomes a point where injector cleaners just can't help the wear and tear that an injector has endured. If the injectors are not spraying properly, quite a few of the problems you are experiencing may result.

With the fuel level sender, it sounds like the sloshing of the fuel in the tank has dislodged the float arm.

Oil pressure of 80psi could be normal for your engine. It should never get below 10psi at idle though. That is when I would be concerned. If it stays above that, I wouldn't worry much about it.

Coolant temperature.. Well I would start with a cooling system service (drain and refill) while you have it opened up to replace the thermostat. While you are at it, put a new Stant safety cap on it. Make sure to check the radiator and heater hoses for signs of degradation.

My head hurts a bit from reading through all of that and I will respond later to the other points you make. Have to start somewhere though.

 

Yeah, i just dont know any chevy guys around here and i figured i could go for broke and post that MASSIVE list.

 

Concerning your injectors..I had the same dripping problem but didn't want to fork out for new ones so I got a "rebuild" kit for them that included new screens, gaskets, O rings and a new pressure regulator.They still drips a little at idle but not as bad as they first did, performance wise they now run perfect. With the air cleaner off, start up the truck and with a flash light, have a look at the pattern of the spray as you rev it up manually with the linkage. Before I tuned mine up you could see the flow almost streaming down but now it's a nice conical pattern with no drips at all. Like i said, I still got a little bit of drippage at idle but it disappears as soon as the RPM increases. I think the kit was about 60-80 bucks. It would also be a good idea to check your fuel pump pressure, with the year of your truck, like mine, parts only last so long regardless of mileage. Good luck.

 

I "paperclipped" it, and got code 45, running rich (as if i didnt already know that). I can hear the dang injectors spitting out gas, andthe only thing keeping me from replacing them is the fact that i dont know if something else could cause dripping and sputtering injectors. I dont want to replace them only to have the problem still there.

Also, when i changed the fuel filter, there was a TINY bit of black in there.Could this have something to do with it?Doesthe black stuffwarrant a fuel pump replacement, even though there was such a small amount? If so, how much of a PITA is that, money and labor-wise?

 

I would start with either replacing or rebuilding the injectors!! Then after if you have the necessary tools, drop the tank and inspect the condition of your pump along with the float assembly and dislodge the float so your fuel gauge properly works. Doing the injectors will clear up the majority of your problems on your list alone!! As far as the defrost on your back window I would trace the wires to see were the grounding out started from then replace everything from that point to the glass and that should get your rear defrost working again.( check the fuse too). Start with the suggestions we have given so far and when you accomplish those let us know how your blazer is doing, if any other problems are still present let us know so we can give additional advice!!!

 

I think im gonna replace the injectors due to my lack of know how on how to rebuild the TB. I would like to rebuild the whole thing but i need the truck to run so i can get to work/school. Also this morning when i was looking at the injectors i was opening the throttle, and saw some exhaust leaking out of the driver side manifold somewhere. i dont think its that bad though.

 

Does your truck also sound like its got an exhaust leak by chance???

 

An exhaust leak would cause an artificial lean condition as the leak would allow outside oxygen into the exhaust, fooling the O2 sensor. Is it possible that something just dripped onto the exhaust?

As far as rebuilding the TB, there isn't much by way of complexity in a TBI throttle body. Should just be a bunch of gaskets. Make sure that you replace the gasket between the throttle body and the intake manifold as this is a common leak point.

 

Thegr81, im not sure what it sounds like, but when i drove by the interstate divider thingy i could hear it clicking. Ive heard from people that's what it sound like, but i dont know.

Swartlkk, i was at advance buying brake pads and got a look at the kit. it had a bunch of gaskets, little screens, and some other knick knacks. I wouldve bought it but problem is i cant return it after ive opened it, so i figured i would get on here and make sure.