help please
 

alright so im having some real problems with my 1997 k1500 with a 5.7 in it, recently my truck had been running horribly, real lack of power and when i go to take off sometimes it would act like it was trying to stall and then randomly clear up, and then one day i went to start it and it wouldnt start, so i assumed that the fuel pump was going out and finally just went out, so i replaced the fuel pump, well i went to start it and no luck, so i was messing around with things and found little problems here and there and finally got it started but it was running like crap, shaking like crazy, and if i try to clear it out or push on the gas at all it stalls, now when i start it, itll run for like 5 seconds and then stall and it will have a blow back through the intake , anyone have any ideas


and i have codes po102, p1406, and p0300

Hmm, fiddle around your distributor a bit. Check wires into the pick-up and ignition control module. Look for pinched wires.

Also check the rubber hose going from the MAP sensor to the TBI. If the rubber is rotten and you try to start on a humid day it will go bonkers. If you have a MAF sensor suspect that. Make sure needle isnt clogged up with dirt or broken.

300 is related to what happens when it is running. Nonspecific misfire
102-MAF low circuit input
1406-EGR plugged downstream.

102 is the only one that sounds relevant.

ive completely switched out the plug wires to test that and it checks out, dist cap seems fine, plugs are fine, and i dont have the TBI i have the spider poppet system, and the MAF has been defective for a while, i have a CAI and i think i used to much oil when cleaning it, ive been through a couple of the options for the misfire, like checking the ignition and even unbolting the exhaust at the manifold to see if the cat converters were clogged, also i just noticed that some of the plenum studs were sort of loose so i just got done tightening them and it didnt really make that much of a difference, lke instead of dying after running for 3 seconds, it stayed running for 5 seconds, ive left the MAF and EGR unplugged before and it didnt stop it from rinning, im wondering if i need to test my injectors

Reading that gave me a headache.. ok, so your truck dies after 5 seconds? And it continues to run normal if the MAF is unplugged? If so, then your truck is dieing from a bad A/F mixture from a incorrect signal from the MAF. Either you have a shot MAF (VERY likely if you over oiled the rechargeable filter, I have heard of that oil killing MAFs before) or you have a leak in the air stream somewhere after the MAF (air tube, TB gasket, IM gasket [very likely since you said you found loose bolts], cracked IM, or a nasty vacuum leak).

Now if I misread that and it still dies even with the MAF unplugged, and you have indeed ruled out all those possibilities mentioned, then it is very likely the spider, injectors, or poppets are not properly functioning. My truck was not firing on #2 cylinder recently because of a clogged poppet. So that is definately likely. Could also be the distributor or even internal damage. Quite a few possibilities. First test I would recommend is taking off the intake (with the MAF unplugged!) and trying to fuel the engine yourself with some ether (starting fluid). If you can keep it alive longer than normal, then it's definitely a fuel issue and you can go from there (pump, filter, spider, regulator, etc etc). If it dies like normal, then you can rule the fuel system out and we can help you work it out from there.

what i need to do is get to the junk yard and get an ass load of parts for some test, id like to test the fuel pressure regulator, injectors, camshaft position sensor, crankshaft position sensor, MAP sensor, EGR valve and i need to get just the black part of the MAF sensor, i ported my MAF sensor and ground that bar that goes across it (for more power obviously) but the MAF sensor actually comes apart into 3 pieces so i just need the middle piece, ive even read that the PCM could be bad, which would SUCK

Just realized I never noticed your first post, my screen popped up with the post I quoted 1st on the screen. Wow I feel stupid.

But still unclear, does the truck run decent with the MAF unplugged? If it runs decent with it unplugged, then that is your problem. If it's dieing with it unplugged, then as I previously mentioned, try using ether to keep the truck running. If you succeed, then look at fuel parts for your solution.

im saying that ive been cleaning things before and have forgotten to plug in the MAF and it starts and ran perfectly fine, and that code has been on for a long now so i dont think thats the problem, same with the EGR valve, i think its the p0300 code thats causing it not to run

Yea, that code is from the MAF being unplugged, I have had the same code before for the same reason. Probably the same thing with the EGR. But unless I keep reading this wrong, you say the truck does run with the MAF unplugged? Again, either your MAF is bad or you have a leak in the air stream, probably the MAF since you used that oil on the air filter.

The dieing after 5 seconds issue isn't caused by the random misfire, but it is very very likely they are both being caused by the same culprit. Which is most likely that bad MAF...

o2 sensor?

o2 sensor would not kill an engine, and it would throw a code. But it wouldn't hurt to unplug them all and start it anyway... wouldn't expect anything though.