Im new to the site. Just got a 90 454SS. It needs a lot of love and was hoping you guys could help me out on a few things.

 

welcome!! what ya needing help with on the truck?

 

I started a post in the classic section. I Just want to get it drivable for now. I tried to replace the smal cap HEI with a big cap HEI. That didnt work out very well. Now the injectors do not get power. Im thinking about just putting it back the way it was today. The main problem is it just doesnt want to run right. First it would run for a while then start skipping and sputtering. Then cut off and not restart. If I let it sit long enough to cool off it would restat. I replaced the O2 sensor. Put new plugs, wires, cap and rotor in it. It still did the same thing. I replaced the ign module with one I had in something else and It did much better. It would stay running but after a while it would idle fine but when you tried to give it gas it would cut off, but would start right back up. If you was easy with giving it gas it would do OK. I drove it and it was doing fine. But if you floored it from a roll it would sputter in the upper RPM's. Right before it shifted. Thats when I put the big cap HEI in it. I know a lot about cars. I have a 71 chevelle that runs 6.60's in the 1/8th at 105 on 87 all motor, but most of my cars have had carbs. Im not completely clueless when it comes to EFI, but I am fairly new to EFI.

 

Your truck looks nice by the way.

 

This is what Im starting with.

 

My chevelle

 

Love those trucks! Good luck with it.

 

Few things I would like to know now. Is there a way to get it to work with the big cap HEI and keep the TBI? If I do go to a carb. Is there a way to use to stock fuel pump? Also I would like to find out what kind of block I have. From what I have read the gen 5 didnt come out untill 91, but I cant find a fuel pump mounting boss on the engine I have and that would say its a gen5. I have a set of 781 heads I want to put on it, but I dont think they will work with the gen5 block. Any help would be great thanks.

 

welcome!

 

i had the same problem years ago with mine when it was still tbi with it falling off in higher rpm range. after trying all the same parts that you have already changed i pulled my fuel pump and the short piece of hose that connects your pump to the hard metal line inside the tank had a split in it and was losing oncoming pressure when the motor turned up. i replaced it along with a new pump and the truck ran like new again.

as far as the stock fuel pump and a carb goes, you can run a good quality regulator and pull the pressure down to 5 or 6psi and be perfectly fine.

you will have to put your stock tbi distributor back in to fire your ignition and injectors...

thanks for the props on my truck

Jamie