I have a 95 blazer with a rich running condition..could my poppet injectors be bad

 

Let me futher this by saying this truck hasnt been on the road since 2007.my plans are to change intake manifold gasket,injectors,O2 sensor, and the truck is a little noisy and found broken exhaust gaskets so I will be changing those out too

 

Checking fuel pressure and leakdown will tell if anything in the entire fuel delivery system is leaking. Before we go any further, we need to know which system you have on your vehicle, (1995 had three different systems).

Does your engine look like this:




Which OBD port is under the dash:

 

Captain
Thanks for your response
Pic 1 you posted..yes that's my engine

2nd set of pics..pic 1 is my port

Something caused this truck to overheat..I just talked to the guy I bought it from and he said it got so hot the exhaust manifolds were glowing red.

Again thanks for your response

Rick

 

You have CMFI, (Central Multiport Fuel Injection) with OBDI engine controls. There is one fuel injector inside the plenum with a line going to each intake port. At the end of each line there is a poppet nozzle that the sprays fuel:





The injector is "batch fired" meaning it feeds all cylinders equally each time any one cylinder calls for fuel. The fuel delivery system has several "weak" points inside the plenum that can leak fuel pressure: Pressure and return lines, (nut kit), fuel injector, "spider" lines, poppet nozzles, and the pressure regulator. Fuel pressure and leakdown must be within specs for this engine to run properly, so it's the first thing that should be checked. Most auto parts stores rent/loan the tester, and sell them for around $40. The tester connects to a service port located just to the driver side of the distributor. You can see it at the top of the image above. It has a black plastic cap, and it's part of the "nut kit", (pressure line). When the ignition is initially turned to the RUN position, (not cranking) the fuel pump is activated for ~2 seconds and then shuts off. Fuel presure must be checked while the pump is activated. Key ON, engine off, fuel pump activated, pressure must be 55psi to 61psi. It must remain above 50psi for at least 10 minutes after the pump shuts off. Check it out and post your results.

 

I will do that this weekend..again tha ks for your quick response

Rick

 

I think presure test is going to have to wait until it gets warmer.I tried to get the guage on there and with it being around 5 degrees out there things don't want to work right I can't get the hose to seat al the way down on the port..and with that engine that port is hard to get to anyway. I'm going to go try it again in a few hours. Any tips on how to get it seated al the way in such a confined area.

Rick

 

I've had problems with that, as well. Are you renting/borrowing a pressure tester from an auto parts store? I've noticed that those tend to be a little "rough". I guess since people just rent them, they don't really give a crap how they take care of it.

Combine that with it being in a hard to reach area, and getting a good read can be difficult sometimes.

I've had to take a kit back, and rent one from a different store, before when I was having problems with one.

 

OK I got it. It went up to 58psi then bled down to 0 in 3 minutes..so I'm leaking somewhere

Rick

 

Next step is to test at the fuel filter, or fuel pump, to determine if the leak is in the pump, or fuel pressure regulator.