454 tbi problems

[78K-5BLAZER]

about 3 month me and my stepdad got a 92 k2500 suburban it has had the 350 changed to a 454 for either a 93 94 or 95 I do not know it is running rich and surging and is idling a little high has new 02 sensor 1 upstream only no downstream on truck and a new temp sensor we cleaned the tbi and rebuilt it we also removed the plug that stops you from ajusting the idle put on a new fuel pump reset the iac 3 times no good check for vacum leaks what is happening map sensor checks out ok I do not know if this matters at all but the tail pipe was cut off by some one there is no cat and there is some thing weird behind the muffler I have look on other sites and can really not get any answers so I figured it was time to finally ask questions rather then search every site I can think of and or what ever pops up on google

 

[Hogback Fabrication]

Were any of the fuel injection parts swapped with the bigger engine? i.e. injectors, throttle body, etc.

 

[78K-5BLAZER]

yes every thing from the 454 even the pcm/ecm was used as far as we know one injector is spraying a little more then the other plugs are old

 

[doubletrouble]

Make sure all the grounds are good. I have a TBI 454 out of a 94 in my buggy, I fought with it for a couple of months and finally had performance fuel injection build me a new set up using as much of my parts as possible. They told me this is one of the only TBI's that needs a minimum of 28 psi instead of the 13 psi like most. I got it all installed and was having the same problems I was before, checked the fuel pressure and only had 9psi. Installed a new pump and everything worked great.

 

[Blue85]

Can't work on EFI without checking the basics.

• What is the fuel pressure?
• Where are the fuel trims at?
• Are you getting transitions on the O2 sensor?

 

[78K-5BLAZER]

we have finally got the idle lower I do not know if it is still running rich or not it is NOT throwing codes it still is surging at idle in and out of gear but it throttles out nice and has all the power I know we installed the wrong fuel pump in it could this cause the surging idle I do not know the fuel pressure I do not know what fuel trims are and I do not know what transitions on the o2 sensor means