89 Mustang 4 Cylinder conversion.

Ok lots of you guys have experience stuffing bigger motors in these fox body's

My kid is running an 89 with the original fuel tank. Added a Holley blue pump with Holley standard regulator.

Pretty sure they removed the stock electric pump but seem to be having issues feeding the the 427 Windsor motor they have now.

He tells me the fuel tank whistles when he takes the gas cap off so I am assuming it is a non vented cap and the tank is going vacuum.

Conversely the carb is acing like it has to much pressure sometimes even tho the gauge is only reading 6 pounds.

So educated guesses on whats going on???

Aerating the fuel cuz it cant suck it out of the non vented tank???

Let me know what you think or have seen on your cars.

Thx.

dkp

You need to start by getting a decent vent into the fuel tank. What is the carb problem like if you run it with the cap off ? Does it still seem to be over-pressured. What size lines is he running?

X2,Make sure the vent hose from the tank is big enough or isn't plugged.

Later Mark.

3/8 fuel lines.

Acts like it is starving out of fuel at times.

fuel looks to be boiling in sight glass sometimes under part throttle.

dkp

I would say sort out vent first cos I believe that is causing all the woes. Could be something to do with bypass in bottom of pump, but doubtful.

x2 Try it with the cap off.

Hi Dean,
How sure are you that they remove the original fuel pump? I think I would double check on the pump being removed, and do a vent then go from there.
When and if they removed the original pump, what did they put back in the tank for a fuel pickup? Since the pump is part of the pickup tube, if the pickup tube is inadequate after they removed the pump, is there a chance it is sucking air under acceleration? Maybe that is where the fuel aeration is coming from.
Are you ready for Seattle in a few weeks? Hope the temperature cools down a little by then. See you then.

They did try it with the cap off recently but I am thinking this pump is messed up now. been on there for a while. At least one other failed holley pump before this one. I agree on the vented tank thing. That was my first thought as well. told him to drill a hole in the cap at the very least.

I also asked about the original pump being removed. IS There a kit or something you can buy for that??

Hoping to be in Woodburn and Seattle both. Depends on a family issue we are dealing with.

dkp

bosshoss wrote:They did try it with the cap off recently but I am thinking this pump is messed up now. been on there for a while. At least one other  failed holley pump before this one. I agree on the vented tank thing.  That was my first thought as well. told him to drill a hole in the cap at the very least.

I also asked about the original pump being removed.   IS There a kit or something you can buy for that??

Hoping to be in Woodburn and Seattle both.  Depends on a family issue we are dealing with.

dkp

If the pump is still in the tank just take the pump off the pick up and add a peace of tubing in place of the pump with a small peace of rubber line.

Granatelli motorsports makes a tank insert with -10 feed and -06 return fittings. Even if he removed the pump and extended the pick-up tube, those original inserts are tiny. I ran the granatelli insert on my 87 small block car and used the return line with a separate pump for nitrous.
Hope this helps,
Russ

Have you tried taking bottom off of pump making sure there's nothing stuck in there.

austin460 wrote:Have you tried taking bottom off of pump making sure there's nothing stuck in there.

I will mention that to them thx

dkp

Dean,
I'm sure you might have, but did you hear about Frank Nelson Sr.?

Yes I did hear about Frank. Helluva guy. Drag Racing in the Northwest will miss him a ton. Used to visit him at his place in Auburn. Great guy.

dkp