Hello everyone, I'm new to the site so bare with me. I have an 87 f150 with a 302ci 4x4 fuel injected. I've got the truck running after 3 years of sitting. I've installed 2 fuel pumps (rear tank and high pressure) 8 injectors, plugs, wires, cap and rotor, timing chain. checked timing, new battery, but the truck still has a hesitation with a little back fire through the intake. Im sure there is something I am missing but I cant seem to find it. Any help would be greatly appreciated.

The problem was 10x worse before I installed injectors.

 

When you set the timing, did you remove the spout.
What's your fuel pressure (to verify regulator is working correct)
What firing order did you use.
Hesitation could be tps or map sensor.

 

Yes I removed the spout, new tps and map sensor. not sure of the fuel pressure, need to get a gauge. do you know what the fuel pressure should be?

 

You forgot one question... What firing order.
Also, what did you set the timing to.
Fuel pressure with vacuum line unhooked should be 38-42. Unless you have a use for a real fuel pressure gauge, don't buy one. See if a parts store has one to borrow. Or I suggest buying a cheap oil pressure gauge and kit, it usually has the 1/16 npt fitting you need.

 

I went by the firing order under the hood on the breather box (don't remember off the top of my head). I went by the white mark someone made on the balancer but now that u mention it I wonder if it is the correct mark. do you know where the timing should be mark on the balancer?

 

The balancer has a "0" on it. And will have degree marks from there to 20 or 30 btdc and 10-20 atdc. Depending on what type of timing light you have, kinda makes it important where you mark the balancer...
How did you time it.

 

removed the spout and checked it that way. timing light is a basic light. + wire, - wire, and a wire that goes to number one with a trigger.

 

So how do you know you set the timing to spec if you didn't verify where that mystery line was.
If your timing light does not have a **** on the back, you will verify that the balancer is marked at 10* btdc, then when you pull the spout, you adjust the timing so that the pointer and 10btdc line up, then lock down distributor. I think the truck may just be incorrectly timed now if you can't guarantee where that line is that you used.
As a reminder, passenger front is number1 cylinder.

 

Thanks for the help I will try this and let you know what happens.

 

The timing was set correctly. After I fired the trick up or started running fine for about 30mins then started to due out again. Found out the fuel pump relay was going out. Truck is running great. Thanks for your help.