OK this is pestering the hell out of me i have a 01 chevy blazer and recently it started to miss like it starving for fuel but only does it once in awhile but is getting worse i dont think its the fuel pump but has anyone had problem with the main injector on the spider pump itself i have replaced the cap rotor plugs and wires and still its the same i had a 93 with a votech and repplaced the spider pump in the manifold and it fixed the problem but this is dooing different things than that one was i was wondering if the injector was going bad or the fuel pump or possibly the relay? any help would be greatly appreciated.

 

Welcome to the forum.
Does this "miss" occur any time or at idle, under load, acceleration or coasting. Does engine coolant temp seem to make any difference?
You can test the individual injectors for resistance with an ohmeter. Each injector should read 11 to 14 ohms.

Sorry, that's all the info I have for now.

 

It does it when im driving no matter what speed im at it has did it since i have bought it but it has gotten worse for about a week now and i didnt know if this had a spider style pump in it or indivdual injectors, but you can be driving and it cuts out and it isnt a lite cut out it acts like its going to shut off but my fuel pump doesnt have a whine to it or anything like that its getting very frustrating cause its getting worse plus i would like to know how to fix the fuel gauge fluctuation i have no other problems but this with my blazer it gets maintained regularly and is taken care of and has 73,000 on it.

 

plus the engine coolant tempp does not matter its always at operating temp when it does it but if your sitting at a idle and try to get it to do it i havent been able to get it to cute out

 

I would suggest starting with a fuel pressure test.
Have you changed the fuel filter?
When you change the fuel filter, drain it and then tap it out onto a white paper towel or cloth. If you see black come out of the filter, that's a good indication that the fuel pump is failing. The black is from the carbon brushes in the fuel pump.

 

I changed the fuel filter about 6,000 miles ago when i did the tune up and i dont really rember it haveing any black stuff in the filter cause i did tap it on a towel to see waht was in there

 

When was the last tune up? If it tends to miss more when it's damp outside, I would look at the cap/rotor and wires. Pull off the cap and see what the terminals inside look like as well as the tip on the rotor. Also, if the button in the middle of the cap is worn flat, replace the cap and rotor. Your wires can be checked at night with a small spray bottle full of water. Just mist the wires and look for stray sparks. You'll see them if your wires are bad.

 

I had the same problem and it was a clog cat! I am not saying that is your problem too but it never hurts to check by taking out your o2 sensors and driving it.

 

When I bought my current 95 Blazer 4 years ago, that is what the seller told me was the only thing wrong with it. It had 110K miles on it at the time and he said that the dealer told him it probably needed a complete fuel injection overhaul for about $1000.00. I test drove it and for 30 miles it ran very well. I bought it cheap for the mint condition it was in. Or at least I thought $4000 was very cheap. After about 500 miles sure enough it started doing it, running rough and stalling and SES light came on. Then it miraculously went away and run great again in a matter of 20 minutes and SES light went out. Drove it for a week and it did it again. I stopped into Autozone and they took my codes and got the usual random misfire, O2 sensor and he saw "low voltage" code. It was running good again and he also said possibly fuel injector problem. When I got home I kept wondering why a low voltage code? Anyway, you guessed it, positive cable was not very tight. I took it off, cleaned it along with negative connection, tightened them both good and drove it for a 200K (turned 324K today on my way home from work) without it ever happening again. I'm not sure that is your problem but it seems a lot of these Vortec engine problems on this website are more electrical than mechanical. I just recently had an episode of badly corroded sparkplug wires that were only 8 months old and caused the same type of symptoms, but you say you already changed the cap, rotor and wires.

 

Although I should not assume that you are talking about a 2001 extreme p/u but most of the 4.3L from 1996 to present have a spider style setup. In 2002/3 GM decided that warranty work on the poppet styles were getting out of hand (my opinion) they switched to the LS1 style multech injectors in the intakes, but it is still a spider style fuel meter body. They just have the injectors in the intake instead of po(o)ppet valves same fuel lines etc.

You could have a fuel pressure regulator problem but since it is intermittent it makes it more electrical.

If the problem happens during heavy wetness check the cap like Kyle says but also check the base of the distributor there are supposed to be two screens that allow for moisture to escape if they become clogged then moisture becomes trapped, causing moisture buildup inside the cap.