Well I thought that maybe RPM’s have anything to do with it but I noticed it does it even at higher revs, like 3000 RPM’s. As long as i keep the gas pedal steady it seems to be fine. Again every time this happened was after driving for a while on the freeway, it never does it in the city. So maybe speed has something to do with it.
You have integrated wheel ends that release your locking hubs on startup, with engine off and no vacuum the IWE move to lockout position, what’s happening when under heavy accel your vacuum naturally will decrease, with a IWE leaking vacuum or vac supply hose leak your hub is pulling towards lockout position, so check hose and IWE to see if they are able to maintain and hold vac, if not replace IWE or repair hose! Common problem, easy fix
3 year old thread, they may not even have the vehicle anymore.
Hello, I already replied to your other post focused more on the 4x4 issue. I’d really appreciate if you could get back to me please.
My 2006 f150 has similar issues. At first there were troubles starting after a longer trip. Now it sometimes doesn’t start at all, until I use starting fluid. I changed fuel pump, fuel filter, fuel pump drive module, fuel pressure regulator, air filter, cleaned throttle body, changed spark plugs, ran a bottle of seafoam in the fuel, changed oil and oil filter.
After all this, the starting issue hasn’t resolved. And now I’m also getting grinding sounds when going uphill which disappear when release the throttle or give it a gas. I can somehow manage the sound from starting by being very gentle on the throttle. I tested the IWE system following a youtube video. Everything checks fine, except that I can’t simulate driving uphill, when the problem actually occurs.
So I’m very curious whether you figured out was was wrong with your truck? I’m thinking maybe one common vacuum leak spot?
Please, contact me if you read this. I know it’s been 7 years, but fingers crossed 