hey guys I have a 1998 4.2 with 1ook on this engine and it just loss power all of a sudden.
I have no codes and I changed a list of items starting with the fuel pump,tps,crank sensor,cam sensor with the syncronizer shaft,coil pack,wires ,plugs still no power!
Starts and idles but can't take your hat off your head!
help please

 

anyone have a guess?

 

Have you checked your fuel pressure after changing the pump? Did you also replace the filter?

Checked for vacuum leaks? Checked the vacuum hoses for wear? Cleaned/replaced the MAF?

Most likely the easiest thing to do would be to invest in something like the BAFX scanner and either an android phone or laptop with bluetooth (or get the wireless version if you are using iphone) and get some data from the truck. Check your fuel trims and O2 sensors at a guess.

 

i hooked up my scanner to it no codes ,looked for vacum leaks and replaced one big line,anytime I change a pump i change the filter but i havent checked the pressure on the new pump. I will do so tomorrow.I haven't changed or cleaned the maf yet but I tried it unplugged and it was no different! thanks john

 

just ran another test and a p1537 showed up and it is bank 1 stuck open on the intake baffles. So tomorrow I will see what I have to do to get it freed up!
john

 

you got it, there's a ton of info on the net.
here's one on
while you're in there do both sides