Cant get my engine to run. Please help!

[87ChevyR10]

Your truck is an '86 with a carb. Does it have an electric fuel pump? If so, is there a fuel pressure regulator installed? Reason I ask is if the truck had TBI before, the TBI units require higher fuel pressure than carbs. If there isn't a FPR installed, then the fuel pump is putting too much pressure into the carb.

 

[Pender1]

Your truck is an '86 with a carb. Does it have an electric fuel pump? If so, is there a fuel pressure regulator installed? Reason I ask is if the truck had TBI before, the TBI units require higher fuel pressure than carbs. If there isn't a FPR installed, then the fuel pump is putting too much pressure into the carb.

No, it's a mechanical pump. I don't think this is the original engine. No TBI components to be found.

edit: I'm going to try and stop by advance and get a fuel pressure gauge on my way home from work. If I can get this thing to run and idle (my starter was giving me problems the other day) I'll see what it says.

 

[Oldrider]

Have you double checked all the plug wires to be sure you don't have two wires swapped?

 

[Pender1]

Have you double checked all the plug wires to be sure you don't have two wires swapped?

I've checked my firing order no less than a dozen times.

 

[Handy Andy]

When you cleaned your carb what all did you do? How far into it did you dig in? Most mechanical fuel pumps will put out around 7psi. This is even a hair high for most edelbrocks.

I recently swapped my old worn out 350 for a 400 that I built. The new fuel pump i installed was putting out about 7.5 psi. I went with a built Qjet from Quadrajet Power and after doing some research I found that Q-jets don't "like" more than about 4.5 psi.

The fact that you can turn the screws all the way in and stay running really bugs me. There is definitely something wrong in your carb. Either too much fuel pressure is overpowering the needle/seat and float, or you have a bad float, or just a bad needle and seat.

I am a long long long ways from a carb expert, I only got into the carb game a couple years ago. I'm sure there are others on here with some better advice, but if I were in your shoes, I'd get that carburetor straightened out before I pissed with anything else. You may in the end find that the carburetor was causing your issues all along.

Another thing you might do is verify your vacuum readings with another gauge if you haven't already done so... Wouldn't be the first time a gauge went south..

 

[Camar068]

The fact that you can turn the screws all the way in and stay running really bugs me.

good catch....i missed that part. Also, I think the eddy's will run on anything higher than 3 psi....so I've read here and there anyway.

 

[Georgeb]

I can't remember since it's been a while since ive worked on an eddy carb so forgive me my asking but it may be relevant. If there is only 5"hg of vacuum are the main jet rods not pulled down? Would that allow enough fuel through anyway even when the idle jets are closed fully? I still suspect a vacuum leak. Simply running rich probably would still stay running in drive to some degree and if and when it stalls it will obviously be because it flooded out. I figure if its too much fuel you would know it.

 

[Pender1]

Well guys, I think I'm going to throw in the towel on this engine. I plugged every vacuum port and installed a fuel pressure regulator and it didn't change anything. The only thing I can figure is there's some major mechanical flaw in the engine and it's not getting fixed by tinkering. I'm playing with the idea of pulling the 305 out of my wrecked K10 and tossing it in just to get me through the summer. Not sure if it's worth the effort, but I really don't want the Blazer sitting in my driveway dead until the Fall, that would break my heart. Thanks for the ideas, I'm sure I'll be back with more questions when I go to trying to put a different engine and trans in this thing.