new guy needs help, no power under load 454

[TheFastMan]

I've been working on thisntruck for quite q while and am losing patience. Its an 88 v30 crew cab, 454 4bbl quad, 4sp with the np205 transfer case. Its a beast and my dream truck. It ran great for the firat month or ao after I bought it, then the problems started. So far I've replaced the bell housing, trans, transfer case seals, rear main, head gaskets, lifters, coil, and had the carb rebuilt. My problem is it has no power under load, cuts out almost dies and backfires some through the carb. I have it set at 10btdc, have about 25 total timing, running full manifold vacuum. I did a compression test and have 130psi on each cylinder. I think the backfire is due to valve adjustment, I'm a novice at best, but the consistant issue is the cutting out/miss under load. I don't think, or hope, its the cam because it ran well before I had to do all this work. Also, I've done plugs, wires, cap, and rotor. I know this is hard to diagnose over the web, but any other ideas? Thanks for any input. Lovely forum here as well.

[12gaige]

Hard to diagnose without seeing it. But i would start with basics first. Make sure timing is advancing properly, make sure accelerator pump is squirting fine, and not saying your stupid but make sure wires are routed/numbered right. Alwayd start with basics first before you start throwing money at it. Pleasr keep us posted.

[VileZambonie]

Check for fuel starvation, kinked fuel line/hose. Do a compression test. Why did you replace lifters? Make sure exhaust is not restricted

[TheFastMan]

My original issues were the trans tarted coming loose from the bell housing and the bell housing feom the engine which cracked the housing, bent the throw out, messed up the input shaft, and I think took out the rear main seal. I put a good used trans and housing in along with new transfer case seals. I started it up after doing that and had a upper end knock, stuck lifter. So, new lifters, head gaskets while I was at it, and had the carb rebuilt because one of the pickup tubes? fellout of place. I have tested compresion, it has 130 all around. Exhaust seems to flow well. What should my total advance be at idle? Also, where does the power wire come from which goes to the distributor? I haven't tested fuel system yet, but that will be next. I will recheck the dumb stuff as well, I'm just dumb enough to have missed something. Lol

[Jr.]

I'm suspect of your valve adjustment with your lifters being replaced. How did you adjust?  Did you replace the camshaft? Did you you torque your head bolts in sequence. A lot of machinists and engine builders don't like to reuse the BBC head bolts because they known to stretch. So many things to consider.

Sent from my SM-N910P using Tapatalk

[moss5472]

My truck did this the other day on the way to work. everytime i would try to speed up to pass someone it would stutter and bog. so i let it sit while i was at work and it did the same thing on the way home. I pulled into walmart and was looking at it and one of my plug wires melted a little and was sparking on my headers. I twisted the burnt part so it wouldnt hit the headers and drove it home fine then replaced the melted wire. Not sure if this is what happened to you but its worth a shot to check.