New video by Shane Powell
New video by Shane Powell

discountlawncare98

Chevy 3500 intake manifold cleaned and new pressure regulator installed but now runs rough and and burns lots of fuel.

Hey Scotty,

I love your show and YouTube videos. They have helped me so many times. 

I have a Chevy 3500 2 wheel drive and it has had multiple problems and I have fixed most of them but in the process I have created a problem too I believe. 

I have: put new control arms, rotors, calipers, brakes, barrings, new oil pan gasket and the truck ran good and felt great. However I noticed after parking overnight that I had some green fluid on my driveway and so I started to investigate and found a bad coolant hose. So I replaced it no problem. 

Now the main problem that has been bothering me for a long time is this truck would only crank with starter fluid in the intake. I thought it was a fuel pump until someone mentioned to me to check the fuel pressure regulator. Unlike most that are easy to get to this one was under the intake manifold plenum. I replaced it and put new manifold gaskets in while I had it off. I also decided to clean the intake and I think this is maybe where I messed up. 

I took the plenum off and sprayed engine cleaner on it and let it sit overnight. The next day I sprayed mineral spirits enough to get it watery and cleaned with rags until it was clean. You will see before and after photos in the link. I then put everything back together and tried to crank it. I got a backfire from the tailpipe. As I continued to crank I got it cranked without starter fluid but it ran rough and I noticed liquid coming from the exhaust and it smelled like gas. I had a friend crank it and rev it while I looked under the hood and I found a crack in the exhaust manifold and there was gas shooting out of it. 

This is where I stopped and I haven't done anything since. The exhaust manifold is not problem, I can repair that. But I don't know where to go from there to get it to run appropriately or the gas coming from the exhaust. I am thinking it may be a fuel related issue under the plenum. Maybe the injectors are clogged, etc... 

Any help would be appreciated and you can see the photos and videos in the link below. 

Comments (2)
No. 1-2
discountlawncare98
discountlawncare98

Thanks Scotty, I will change out the exhaust manifold and fuel injectors and report back. When you say every plastic part you are referring to fuel injectors? I plan on replacing the entire fuel injection. But I wasn't sure if you meant the plastic plenum needs to be replaced as well? Thx

ScottyKilmer
ScottyKilmer

Editor

classic signs of injector problems which those systems get. Now if it's vortec system, replace EVERY stinking plastic part in it, they go bad with age and fixing one at a time is foolhardy. Seen guys try, all failed unless changing the whole plastic system out