New thread, and thanks in advance.

Trying to analyze a starting issue. As of now, I've checked my in tank pumps for my dual tank 86 2.9 Ranger. I have verified that the selector reservoir, and the tank selector switch are not plugged. Lines are good. I can get a stream when I check, (I rig a hose after the reservoir). Get a good stream, but on two different gauges, no reading. RonD has told me that the spec is 9 PSI. If I can get a lead on how this appears, or if I should take off the bed and check right at both pumps, I'll be on it.

Thanks so much.

tony

 

Easier to do a Volume test.

Most fuel pumps will have a GPH rating, Gallons per hour, or Liter per hour(LPH) now, lol

To calculate what an engine needs you use Horsepower times .5 divided by 6

2.9l is about 140HP x .5 = 70 divided by 6 = 11.66 gallons per hour, so 2.9l would use 11.66 gallons at FULL WIDE OPEN Throttle in an hour

I find pints easier to deal with, 8 pints in a gallon
So 11.66 x 8 = 93.28 pints per hour, then divide that by 60 to get pints per minute, so 1.55 pints per minute from a fuel pump would be required, for the 2.9l, more is better but not needed

So get a container and mark it for pints, if you have a measuring cup, there are 2 cups in a pint, so use water in the container for gas and mark it for pints.

Then use a watch and time it, 1.5 pint in a minute, I would expect over 2 pints but 1.55 is all thats needed

Pressure is a function of a higher speed pump and resistance at the engine end, can't build up pressure unless there is resistance.
And if there is not enough Volume at the pump then pressure can't be built up by the resistance

 

Gotcha Ron, thanks. Lots of good math there. Thanks so much for laying it out in such detail.

tony

 

Your welcome

And just to be clear, this is to calculate what a normally aspirated engine needs based on its horse power, a minimum requirement, not what a fuel pump should deliver, that would be something the fuel pump maker would post, yours could pump 3 or 4 pints a minute(30GPH), which is great, and you'll know that's not your problem

 

Ron, thanks again for all that detail. I checked the volume on both tank pumps. Front one puts out around 5 pints in a minute, the back around three.
Tested the high-pressure pump at the rail with the Autozone kit. Zero pressure, and heard a squish sound, like the purge valve was letting gas blow by.
Waiting here for my new high pressure pump to be delivered. Today, I will pull the injectors off of the rail, look for any signs of leaking. I did have the fuel rail checked for leaks, and it checked out good. Mater of fact, the guys thought it was weird that I was even there in the shop.

When I assemble everything, (seen your earlier posts about fuel issues), I will NOT hold the pedal down. I may crank it over a bit with the leads off to the coil. As far as fuel goes, this is the end of the line.

Thanks,

tony

 

I wanted to post the conclusion of THAT problem: It was not starting because the engine wasn't aspirating--the catalytic converters were blocked. (I'd passed a smog test 4 days before the engine died). Never saw that coming.

Thanks for all your help.

The story isn't finished. The truck has been in two different shops since the end of January. I have an idle issue that Reno mechanics can't or won't find. Just had the IAC replaced, and the truck runs good. Then, well, another issue that I'll search the threads for.

Thanks for the help! I learned a lot.

tony

 

Hello I'm Jen. I need some help with my idle problem. I had the fuel pump replaced and then the pressure was so high that it was idling at 3000. I tried to put gas in it but it sprayed back out. Now after sitting for a month the idle starts at 2000 then drops to 1500 for a minute then dies.

 

Hi Jen
Welcome to the forum

Our model Rangers were made from 1983 to 2011, and there were many changes over those 28 years
So we need some help from you

You should start your own thread, and include these things so we can help
YEAR of Ranger <<< this is the BIG one
Engine size
2WD or 4x4
Manual or automatic transmission

 

I've been trying to figure out how to start a new thread here. If you could point me in the right direction I'd be glad to.
Thanks! Jen

 

From the main webpage select a Sub Forum, like "General Discussions" or specific engine size forum or ???, your choice depending on your topic

Click on that sub-forum then after that page loads, look just above where the Posts start, and to the Left, you will see "+ New Thread", click on it

Type in your title for the new thread and then the topic info

Always include the YEAR of the Ranger in question
And engine size, manual or auto, 2WD or 4x4, if you think that will help in someone answering your question, but YEAR is the big one