Here are the details:
I have installed a rebuild engine about 20,000 miles ago. At that point I installed new cap, rotor, wires, and plugs. A new fuel filter about 5,000 miles ago. I have replaced the fuel pump a while ago... but not exactly sure.

In the past week is the first time that i have notice this issue.

Here is what happens:
I drive somewhere, I shut off the p/u, I am in the 'store' or at home for about 20-45 minutes b/f I leave again. I crank the engine... it sounds and feels like it is hitting on half the cylinders, and will sometimes died. As I am sitting in the vehicle, I can smell the exhaust, and it smells like it is flooded. After about a minute, it revs up and starts to run fine. There are no performance issues after that.

If the engine has not run for about 5-10 minutes, I crank the engine and it runs fine.
If it sits for more than 60 minutes it will start fine.
Also if it sits overnight, the next morning it starts right up... no problem.

I have been watching the oil level, and as of now, I am not really seeing a rise in the oil.

I have a feeling that it is an injector issue (as the injectors are original (to my knowledge), therefore have approx. 190000 miles). And that one of the injectors are bleeding into the TBI.

Do they need to be replaced, or is there something that I can run through the fuel system to clean the fuel system??

I have talked to a friend and they said to run a gallon or so of E85 fuel (in a full tank of fuel) and that may help to clean the fuel system. Could this be true?? Or what is my best option at this point.

Thanks in Advance,
ptrkptz

 

Which engine do you have (2.5, 2.8 or 4.3)?

Do you have the throttle body model number?

I assume the E-85 would be to collect any water present in the fuel system ... I can't find an on-line owners manual for 93 Chevy but recall my 90 Subaru owners manual cautioned against using ethanol mix, claiming it could damage injectors.

I don't recall if GM had similar cautions for any of the early 90's engines.

 

on my 95 s10 (4.3) I had similar issues, most of the time it required an "injector flush/clean" I think I did that every 25-40k miles, not to pricey, and did improve things, other things to check is bad plugs/wires, same symptons if not all cylindars are firering correctly, I also had a bad EGR that caused bad missing, rough, power loss etc...

I do not recomend a DIY injector flush (i.e. pouring any chemical in that states injector clean)

 

I had a similar problem with my 91 s-10 and i found that my injectors were dribbling instead of spraying an even pattern while running. Its easy to check when its kind of dark with a led flashlight shining on the fuel as it comes out of the injectors. I tried to use some injector cleaner and saw a very slight improvement, so i replaced the injectors and never had the problem again.

 

So the problem was one of the injectors going out. I found a used throttle body... I am just going to replace the entire TBI... does anyone know what the TBI is supposed to be torqued to?

 

BTW -- it is a 4.3

 

Well the haynes manual says that the throttle body nuts should be torqued to 144 in-lbs.

 

running e-85 in a non flex fuel vehicle is not a good idea, the ethanol is caustic to aluminum and can damage aluminun fuel system parts