stumbles and runs bad when put into gear.
 

So once again I have to post thing about my K5 not running right. I thought I had it figured out. Any ways here's a list of things I have replaced. New 700R4 with converter (installed last Nov 2010) only put 1300 mile on it so far, new T-case (installed last weekend), water pump, 140 amp alternator, AIC, TPS, fuel regulalor, fuel filter, new spark plugs and wires, new distributor and cap, headers and exhaust, EGR, PCV valve, coolant temperature sensor, 3 core alumium radaitor and dual electric fans. It will start up like a champ and idles fine, but once it goes into gear you have to work the pedal to keep it running. It will stumble, hesitate, has no power, and will die on you if you let it. Tomorrow I am going to install a new fuel pump. Thats the last thing I can think of so if you have anymore ideas, thoughts or guesses please send them my way. I have till Nov 4th to get my Blazer running for a Elk and Mule deer with my dad.

P.S. I have a 1988 chevy K5 Blazer with a TBI 5.7 Liter engine that only has about 20,000 miles on it.

timing comes to mind have you checked that

Have not and to be honest I totally didn't even think about my timing. I will give that a go tomorrow as well. Thanks

I checked my plugs and even thou I just got them a few months ago, they were all fouled up. I cleaned them up and place them back in the block and now I can put it into gear with out the motor dieing. It still has some hesitation here and there. I think I am just going to replace them all with new one and see if thats fixes it.

But if that cures the problem then you need to find out why they got fouled so quick, or you'll be back to square one.

if they fouled in just a few months, your problem will most likely return if you just replace them. without seeing them i would say your running rich but thats just a guess, i would look at a solution to that if you dont want to keep replacing plugs.

Did you check timing yet?

Your totally right about running rich, they we all really wet and black. Last November was when I had it timed and I've done a lot of work to the engine since then. So I probably should get it timed again. Should I put in the new plugs right before I do that. I'm still a rookie to all this engine stuff and I am learning as I make mistakes. Thanks for you help.

I'd make sure it's running correctly first before you put in new plugs. I know you say you cleaned them already, but I don't know how, so here's how I do it. Just take the old plugs out and hit the center electrode and ground electrode with some 150 or 200 grit sand paper until you can see bare metal. Then use a small wire brush to clean off any other crud (including any sandpaper residue). Set them to the correct gap and reinstall. After you get your truck running properly then put the new plugs in and make sure they are set to the correct gap - don't assume that when you get them from the store that they are set correctly.

Well for now I cleaned the plugs how you said and reinstalled them back inn, since I am not throwing any codes, all I can do from here is take it to a mechcanic and pay their stupid cost of repair. Although I did have one last guess and that was maybe my injectors are toast and their just dumping to much fuel. Now that I recall after I had painted and installed all my new stuff and hooked everything back up. When I first started it the injectors where dumping so much dam fuel it was just flooding out big time. I had to unplug both the injectors in order to start my blazer and then plug them back in once it fired up and since then it has ran like crap.

Ok, so I took my Blazer in to have it fix and $260.00 later they don't have a clue whats wrong with it. They said they thought it was a vacuum leak, but no leaks. Does anyone have any other ideas for me to look at. No codes, it will start up quick and idle fine, throw it in gear and it hesitates, stumbles and wants to die. Plugs are getting a lot of fuel (they are wet when I pull them out). I was thinking my injectors are spewing to much fuel. I have 16 more days till I leave to Montana for a Elk hunting trip.