When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I have a 1992 F150 with the 5.0. I very recently put a refreshed motor in place of the old one and it started out great. The truck ran beautifully for about a week or two. then I noticed it losing power and now it cranks for a solid ten seconds before starting. The motor is from a 1995 truck and has the updated firing order. the old motor had similar issues but i wrote them off as just a wore our old engine but the new one is doing the exact same things. A ew thing the truck is doing is it will have absolutely no power until it gets revved up to about 2 thousand RPM then you can feel it kind of kick in and then once it gets close to 3 thousand it feels like someone flapped a switch and the truck starts making good power. I'm at a lose and have no idea where to even begin with it. new motor has less than a thousand miles put on it. Any input would be very helpful.
1) Fuel pressure check may reveal your hard start issue.
2) Checking codes is a good idea, even if there is no check engine light.
3) Removing the computer from the kick panel and opening it up to inspect the board for leaking capacitors and corrosion is easy to do.
Ok sorry to be the guy to make a thread then disappear but life got extremely busy for a second. I finally got a break to run a fuel pressure test and I believe it’s fine but one of you may tell me otherwise.
With the engine off i was getting 40psi and it would leak down to about 30 ish once the pump timed out.
Running with the regulator attached still it got 30psi
running without the regulator I was getting 40 and revving the engine didn’t change it.
Little side note, the exhaust sounded wayyyyyyy different with the regulator unplugged and much healthier at that. Is it possible I have the wrong regulator? Again sorry for the hiatus but I’m back for a little bit.
The fuel pressure should not be leaking down to 30.. it should stay at 40-45 psi with the engine off and the key on. What is the leak rate? It should be less than 1psi per minute. If it's more than that, then you have a bad regulator, injector, or fuel pump check valve.
You're psi numbers sound correct, but on the low side of acceptable. If the engine runs better with the fuel pressure regulator vacuum hose removed, then you probably have a massive vacuum leak. Check your pcv hose, pcv valve, and brake booster for leaks.
You might want to also measure your map sensor for the correct hertz. Check it with a multi meter and a vacuum pump... Don't just replace it.
When I say the pump leaks down I’m mean that as soon as the pump times out or I shut the key off the gauge goes immediately to 30-35psi. Then it will hold that for as long as I have the gauge hooked up. I’ll check the map sensor as soon as I get the chance. How should I go about using the vacuum pump. I have one for air conditioning units, will that work or do I need something different?
When I say the pump leaks down I’m mean that as soon as the pump times out or I shut the key off the gauge goes immediately to 30-35psi. Then it will hold that for as long as I have the gauge hooked up. I’ll check the map sensor as soon as I get the chance. How should I go about using the vacuum pump. I have one for air conditioning units, will that work or do I need something different?
A hand-vacuum pump with a gauge is the most accurate way, but you can just suck on a hose to change the vacuum if you want. You just looking for a proportional change in the hz. The more you suck, the lower the hz.
So I tested the MAP sensor to the best of my ability without a vacuum pump. I read in another thread that key on engine off I should have between 152 and 155 Hz and with the engine running it should be between 93 and 98 Hz. Well with my engine off and key on I have about 157. 156.9 to be exact and with the engine running I have 104Hz exactly. Seems high according to the other forum but not super high.
The forum in question: https://www.ford-trucks.com/forums/1...-testing.html#
Forgot to mention I also have about 2.77 V to the middle wire. Is that to high. The other forum mentioned it’s supposed to be at 2.5 V but didn’t mention a range.
Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath
Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.
