Sometimes is seem fin but quiet often these day on acceleration it will work fin for a lil pedle but when i hit the pedle down it is like the engin is being strangled power and RPMs Drop if i keep it held down it will almost die.
no lights or codes and idiots at the dealer want to rebuild the engine when that was done only 40k miles ago.
has full compression, fule pressure, fire, etc.

anyine ever had this issue before.

time for a basic tune up, sounds like you might have a misfire, you say you have spartk, but so did i on my fullsize and when i pulled the plugs out the porcilin was missing on some plugs, the cap i was jsut amazed i had spark after seeing how that was... so pull the cap and roter off look at them and check your plugs and replace the wires never hurts

Well all of that is new for the most part just put new coil on it as well and heavy insulated wires. plugs only have 40k on them

How's your converter...could be blocking up...

hmm... yuve got me, ill ask around and see what i can come up with, sorry i cant be more help

Checking back to see if any 4.3 vortech experts have seem my issue.

short of replacing all of the sensors most of the electrical system is new
still loses power when i put the peddle down like the enging is being strangled

Get A Tech Manual And Check Your Pick Up Coil In Your Distributor

Check your fuel pressure and go from there.

take off your mass air flow sensor your check engine light will come on but it wont hurt anything then drive the truck thats most likley your problom if it is your choice you can leave it off or buy a new one but you dont need to run it if you can deal with your check engine light on

take off your mass air flow sensor your check engine light will come on but it wont hurt anything then drive the truck thats most likley your problom if it is your choice you can leave it off or buy a new one but you dont need to run it if you can deal with your check engine light on

What the hell are you talking about?!!

Our engines need the MAF sensor to run right so in the future, if you don't know what you are talking about, then can the bullshit and do not post at all.

Jesus, yea dude, remove the MAF sensor, like, the engine doesn't need it.

WTF are you thinking? It is one of the most important sensors on a 1996+ 4.3L.

Well all of that is new for the most part just put new coil on it as well and heavy insulated wires. plugs only have 40k on them

Explain all the new stuff you have used for your tuneup.

same problem , good tune up, air and fuel filters, coil,
new map, and still had the same prblem. also timing was good. checked fuel pressure and gage read 10psi, which
is somewhere inbetween. 3 months and could never figure it out until the fuel pump went out. changed it
problem fixed. dont really understand how i got
good pressure reading with a weak pump. i guessing
but at idle it was fine but on acceleration it just couldnt keep up pressure. does that sound like a good guess on why i had good pressure reading?
well i hope that might help.

same problem , good tune up, air and fuel filters, coil,
new map, and still had the same prblem. also timing was good. checked fuel pressure and gage read 10psi, which
is somewhere inbetween. 3 months and could never figure it out until the fuel pump went out. changed it
problem fixed. dont really understand how i got
good pressure reading with a weak pump. i guessing
but at idle it was fine but on acceleration it just couldnt keep up pressure. does that sound like a good guess on why i had good pressure reading?
well i hope that might help.

I am talking to the thread starter.

What the hell are you talking about?!!

Our engines need the MAF sensor to run right so in the future, if you don't know what you are talking about, then can the bullshit and do not post at all.

Jesus, yea dude, remove the MAF sensor, like, the engine doesn't need it.

WTF are you thinking? It is one of the most important sensors on a 1996+ 4.3L.
Do they even run without the MAF?

Nope, in most cases the engine will die immediately if you disconnect it.

i started mine, unplugged it and it stayed running, but it didnt sount healthy at all

Yea, it will default to limp home mode in most cases.

Default sensor values.

Having same issue on low RPM accel...runs great over 25 Mph. Changed fuel/air filter, pump is 15 month old,vac lines are good...in da' hood. can someone guide me through the troubleshooting process from "free - done by me" to being broke for a week. most likely three.

if memory serves you need 40-50 psi fuel pressure, i had 20 and had the same problem fixed by a new fuel pump.

Thread is now over 4 years old.