Ok, for starts. Truck has right at 200,000 miles and I am nearly certain the IP and Injectors are original.
Truck is an 84 with stock water seperator and stock fuel filter(I have a newer all in one but its not on yet)

Put on an electric fuel pump a week or so ago. It starts much easier. First time on the highway with it was today. Get it up to about 55(4.10 gears) and it starts surging a bit. Step down on the pedal and it runs like crap, feels like its running out of fuel. White smoke pouring out of the exhaust. Drive it around town and its fine. I switched tanks just to rule out a tank issue. Still happened.

I put the fuel pump right in front of the tank selector and did disconnect the mechanical fuel pump. I also removed the fuel heater as I had some strange fuel leaks. Its not a cheapo pump either, its a mallory 110gph pump.

I haven't really checked it out yet, so I am going to check some things like voltage to the pump, fuel pressure at the filter etc. Figured I would post and check responses after I check it out.

 

if your injection pump has that many miles on it its probably got worn advance piston that is sticking

 

110 GPH at what pressure?

Fuel pressure over about 7 PSI changes the timing.

 

Its 7psi is what it is supposed to be. Haven't checked what it is yet. Will get to it tomorrow.

 

<TABLE cellSpacing=0 cellPadding=0 width="100%" border=0><TBODY><TR onmouseover="this.style.backgroundColor='#f5f5f5'; " style="BACKGROUND-COLOR: #ffffff" onmouseout="this.style.backgroundColor='#FFFFFF'"> <TD class=overview-c1 width="25%">Free Flow Rate:</TD><TD class=overview-c2 width="75%">110 gph</TD></TR><TR onmouseover="this.style.backgroundColor='#f5f5f5'; " style="BACKGROUND-COLOR: #ffffff" onmouseout="this.style.backgroundColor='#FFFFFF'"> <TD class=overview-c1 width="25%">Maximum Pressure (psi):</TD><TD class=overview-c2 width="75%">7 psi</TD></TR><TR onmouseover="this.style.backgroundColor='#f5f5f5'; " style="BACKGROUND-COLOR: #ffffff" onmouseout="this.style.backgroundColor='#FFFFFF'"> <TD class=overview-c1 width="25%">Inlet Size:</TD><TD class=overview-c2 width="75%">3/8 in. NPT</TD></TR><TR onmouseover="this.style.backgroundColor='#f5f5f5'; " style="BACKGROUND-COLOR: #ffffff" onmouseout="this.style.backgroundColor='#FFFFFF'"> <TD class=overview-c1 width="25%">Inlet Quantity:</TD><TD class=overview-c2 width="75%">Single</TD></TR><TR onmouseover="this.style.backgroundColor='#f5f5f5'; " style="BACKGROUND-COLOR: #ffffff" onmouseout="this.style.backgroundColor='#FFFFFF'"> <TD class=overview-c1 width="25%">Inlet Attachment:</TD><TD class=overview-c2 width="75%">Female threads</TD></TR><TR onmouseover="this.style.backgroundColor='#f5f5f5'; " style="BACKGROUND-COLOR: #ffffff" onmouseout="this.style.backgroundColor='#FFFFFF'"> <TD class=overview-c1 width="25%">Outlet Size:</TD><TD class=overview-c2 width="75%">3/8 in. NPT</TD></TR><TR onmouseover="this.style.backgroundColor='#f5f5f5'; " style="BACKGROUND-COLOR: #ffffff" onmouseout="this.style.backgroundColor='#FFFFFF'"> <TD class=overview-c1 width="25%">Outlet Quantity:</TD><TD class=overview-c2 width="75%">Single</TD></TR><TR onmouseover="this.style.backgroundColor='#f5f5f5'; " style="BACKGROUND-COLOR: #ffffff" onmouseout="this.style.backgroundColor='#FFFFFF'"> <TD class=overview-c1 width="25%">Outlet Attachment:</TD><TD class=overview-c2 width="75%">Female threads</TD></TR></TBODY></TABLE>

 

That should be fine, it has a little more free flow than the Holley Red that several users have had good results with.

55 MPH with 4.10 gears should be about 2400 RPM.

How many miles on the IP?

 

My guess is it has 200,000 on everything. When I got it, it still had the painted gray return lines on it so I would assume it hadn't been touched, but otherwise I have no idea.

The truck acts like it has at least one leaking injector and maybe one that fires too early. Seems to have a slight rattle even after I retarded the timing. Seems to have gotten worse too. Thinking its time to do the injectors and IP.

I think my current problem has something to do with the pump just because it didn't do this before I changed the pump.

 

The old injection pumps had a plastic ring inside the IP that would come apart.
One thing to look for that indicated this was happening was chunks of black rubber or plastic in the return line elbow on the IP.

When that ring came apart, the timing would change as you drove down the road.

When my original IP failed, that is how it acted.
After I changed the IP, the engine ran better, but it still did not run as well or as smooth as it should have until I also changed the injectors.

I will say that the increase in fuel mileage did pay for the IP and injectors in about 1 year of driving, but I drive mine every day.

 

Well, checked the fuel pressure. 11psi after the filter. Turned it down to about 7. I have a couple regulators. Would I benefit any by adding a regulator and turning the pressure down further? If so what should I shoot for. I am pretty much at the lower limit of the fuel pump adjustment.

Planning on an injector and IP change here soon, just want to make sure everything else is in order before I do that.

 

Took the truck out for a drive after turning the fuel pressure down. Seems to be a slug.
Took it on the highway and its still doing the same thing. Acts like its starving for fuel.

 

Any smoke while this is going on?

 

The other day it was white smoking looked like a crop duster when it was doing it. Today I didn't notice as much

 

I guess I should add that it was only smoking when it was running badly while I had the pedal to the metal and at higher speeds. Seems to surge a bit at a cruise speed 60mph.

 

check out my video on youtube.com/bssproguy07 my truck does the exact thing. Let me know if that is the problem you are experiencing with the smoke and all. Mine used to get to 45 and wouldnt go nemore pouring out the smoke....now it dont run at all.

 

disconnected the electric pump and reinstalled the mechanical.

Took it for a drive. About 5 miles on the highway and was fine. A bit of city driving then back on the highway for another 5 miles and it was fine again. several full throttle runs from 55 to 70 and plenty of steady cruise.

So what the heck is going on? Thinking either I have too much fuel pressure(It should be right at 7-7.5) or I am having issues with the stock water seperator.

By the way my test drive was to work to get my 3" mandrel bent exhaust that I bent up for it today. Need to work on the Ram air also then I am done till the turbo goes on next summer.