I got an old 1989 F-150, manual, in-line 6 engine, with an 8-foot bed. I use it for hauling landscaping equipment, as i am starting a business. i will likely start hauling trailers with it this summer, but I also just want the engine to give me more power. What are some things I could do to up the HP, or a better truck in general. I’m not looking to make it into a 350Hp monster, just get a little more out of it. I am in high school, and so cant go spending thousands of dollars, but I’m willing to put a little into it. I try to work on it myself so I learn engines, and because its interesting. I can spend some on it. So I’m wondering what can I replace or add that would do this?
First, the idle dies on me when i put it in neutral, or gets stuck at 2500rpms. is this a vacuum leak, or the idle-air control valve?
Too many questions. You do not need to worry first about more power but first get the engine to running normally. I have no answer for your problem with idle but get that fixed first before you do anything else. That is why there are so many car repair places, maybe someone else here can help!
The 6 is a good engine and if more power is a must then you would be better off just swapping the motor out for a 302 or 351 or trading the truck for one with a V-8.
To perk up a 6 cylinder and get noticeable gains you would have to spend some serious money. A cold air intake, exhaust mod, etc. will not do it. Serious grunt would take cylinder head work and probably a custom camshaft grind and that would be costly on an engine that rarely if ever sees performance work or parts being applied to it.
The idle problem sounds like an Idle Air Valve problem although a vacuum leak and/or sticky throttle could also be involved.
There’s several books about hopping up Ford motors at most larger Barnes and Noble bookstores. Go to their “Transportation” Section and take a look. Your local public library probably has something of interest there on this topic too. However, unless you are doing it just for your own interest, I doubt the payback will be worth the cost in $$ and your time. You’d be better off trading in your existing truck and buying another truck with a more powerful engine, if that’s what you think you need. If your state has stringent emissions standards, that’s another reason to avoid modifying your existing truck.
Inconsistent idling can be due to the idle-air control valve like you say. All that thing does basically is the same as if you pushed the gas pedal down a little further. It is supposed to bump up the idle when the engine is cold or if an extra load is put on the engine, like if you turn on the AC. I donn’t think the IAC is usually able to get the idle speed to 2500 rpm though, so unless it’s really broken, I doubt that is the problem. Does it idle-up ok when cold, then gradually drop the idle speed as it warms up? If so, then the IAC is probably ok.
More likely some kind of air leak. It could be coming in from anywhere, like at a worn throttle valve housing. But like you say, it is probably coming in through a vaccuum line. That’s the first place to look. Vaccuum lines originate at the intake manifold, some before the throttle valve, some are after. Since the problem is idling – not hesitation on acceleration – it is more likley one of the “after” vacuum lines that is the problem. One of the gadgets one of these vacuum lines is controlling has probably sprung a leak. It could be anything from the brake booster to the EGR. Mechanics have a hand-held vacuum gadget, which they use to test each device to see if it holds vacuum.
george, the idle does do that. when i start it cold in the morning, it idles at like 1500, then drops to about 600 once its warmed up. but the engine dieing or getting stuck high has no relation to how long the engine has been running. its completely random, although does happen slightly more if i let the rpms get to about 3000 while in gear.
how would i find a vacuum leak on my own? since theres no way to predict when it gets stuck, and when it does im usually on the road, and cant pull over. Im more concerned about it dieing because it has happened to me when getting on or off highways, and i loose power steering. Its almost caused a wreck, but i got it back on first.
Ducktaped…Is there an auto shop class at your high school? If so, maybe you can get some good advice from the instructor, and since you are interested in this stuff, maybe take a class next term. Or maybe you can get one of your friends in the class to help you work on the truck after school. Here and there some of this might be useful for maintaining your landscape machinery too.
This is probably a good vehicle to learn on, and it will be immensely satisfying to drive it after you personally figured out the problems and fixed them. Probably nothing insurmountable here. You sound capable of learning what you need and making the truck run well.
For finding the PCV valve and other parts, try autozone.com…they have a link on their website that helps you locate where the parts are on a particular vehicle (look for “repair help” near the right in the orange stripe…then “component locations” within that). Or go to a parts store and ask to see the proper PCV valve for your truck, and with that in hand (and advice from a store employee), it will be easier to locate the one on your truck.
Good luck, and report back with progress. Be sure to check oil and coolant levels regularly. Best wishes with the landscape business.
The best way of determining if a vacuum leak exists is with a vacuum gauge if used properly.
A vacuum leak can cause an idle problem and so can an Idle Air Valve. From your last post I gather the truck is also dying at speed. If that’s the case there could be a problem not related to vacuum leaks or Idle Air Valve faults.
Dying at speed could be a fuel pump intermittently failing and it could also be due to an ignition module. Your truck should be a TFI module model and these are known to be problematic; especially in warmer weather. That would be the little gray module on the side of the distributor. Do a net search for TFI Settlement and it will be fully explained.
I would agree that a course in basic automotive maintenance might be worthwhile. And if that truck has the Overdrive 4-speed or 5-speed manual transmission with a rear end ratio taller than 3.5;1 it will be difficult to handle much of a load. I have pulled 24’ pontoons with one of those and it requires some effort. If the engine is running properly and the transmission is working well you might check the rear end ratio and if it is below 3.5;1 shop around for a salvage axle with 4.0;1 or lower… NOTE; higher rear end numbers equals LOWER rear end gear ratio. For instance, a 5.0;1 will allow that truck to pull stumps.