Any Suggestions??

[dmeeks]

Hey guys Im new here and trying to help a friend out who just moved to Canada. He has a 1994 Yukon that used to have a 350 TBI. He has put in a 1990 454 with TBI. Hes done a great job except it has no guts. In park it runs and sounds great, slight chug in idle. Driving...now theres the problem. Driving down the road easy on the gas it seems ok. If you go wide open throttle it does kick down but the thing "chugs" like it wants to go but just doesnt have it. It goes faster but "chugging" like its missing or not enough fuel or something. Hoping some one here can help..I have a couple pictures of the engine bay. I am not sure how to post them on here though... Any and All help is appreciated. Thanks to those in advance

 

[Donnie Yukonie]

As Per the photos You can post them Using Photobucket as a Source, Not to familiar with a 90s 454 to know enough about them sorry hope someone else will chime in

 

[TxDrewski]

I had a 454 SS. Started doing the exact same thing. I wanna say mine was the coil and maybe one of the plugs but I just cant remember. I suppose id start there. Probably not much help lol, but I remember exactly how mine felt while accelerating. Felt just like you described. Miss that truck

 

[dmeeks]

thanks so far guys...Yeah I replaced the coil and all the plug wires. Still no change...I was thinking maybe its either timing or fuel or he tightened the rockers too much affecting the valves opening and closing.... going to check the cap and rotor tomorrow...see if I see anything there too....

Thanks for the heads up..ill have to remember my photbucket account lol

 

[SunlitComet]

um, is using the proper computer and programming?

 

[dmeeks]

yes apparently he sent out the computer and had it reprogrammed... heres some pics

[/URL][/IMG]

[/URL][/IMG]

 

[TxDrewski]

If the PC plugs and wires are good I think your right on the cap and rotor Id check that next.

 

[SunlitComet]

um, what about fuel pressure regulator AND fuel pump designed for the 454?

 

[dmeeks]

I was thinking of that too. In tank fuel pump.... I have changed in tanks before but I cant seem to find any high flo in tank pumps...can I and how could I convert it to an inline feul pump? I see there are adjustable regulators and ill try looking into that as well. Thanks for all the replies. really helps my head get in the right direction

 

[SunlitComet]

just replace the in-tank unit. the big block use at least twice the fuel pressure at 26-32 psi. assuming all other components of the assembly are the same just replace the pump itself at about $70 for a delphi oem unit at oreilly auto.