I own a 1985 F250 with an EFI 302 and the T-18 4speed tranny. The problem is that it dosen't seem to have much power. When driving if you step on it it would just make like a loud clicking/ticking sound and thats it, it wouldn't accelerate or speed up it just made noise. I plugged the EGR and it is way better but there is still room for improvment. I live in hawaii and they don't do emissions tests or even look for the cats so anything goes in hawaii. I was thinking about removing the cat but wasn't sure. Any thoughts? I have a very small budget so I don't want to spend much if any money. I have also changed my fan due to the clutch going bad. I am very cheap and took the fan off my mustang. The difference is the fan off the mustang is direct drive, no clutch. Would changing this help any. I was also considering changing over to electric fans.

 

I also want to mention that It has had a tune up,8.5mm wires Bosch platinuim2 plugs, and i have done a compression test and the result is cylinders 5-8 are all from 140-150. Cylinders 1-4 are 140-155 and #4 is 125 psi. Is this the problem or what would that mean. Need of a valve job, new head gasket?

 

The biggest problem you have is a 302 is too small of an engine in an F-250. That small of an engine in that heavy of a truck is just not a good combo and a 302 is not known for torque, which is what you need to get off the line. You could get headers, true dual exhaust or even an ignition upgrade to something like an MSD box, but it's still just a 302.

 

I was going to take the cat off and run dual exhaust. How much would that help?

 

I'm not sure you want to take the Cat off the truck. Since it's fuel injected, the computer has to have all the emmision components in place to work right. If you run a free flowing dual exhaust with high performance cats, you'll make good power. The more air you can get in and then out of the engine, the better. If you get a K&N air filter and an MSD ignition to burn the fuel more completely, you'll be good to go.

 

I don't see any problems with those compression numbers, it should run fine at that. First thing I'd do is remove those platinum spark plugs, only Ford trucks that run on those are 97 and up modular motors. Older SBF's and SBC's for that matter don't like them, it's actually the ignition system that doesn't work well with them.

Are the other basics ok? timing, advance, vacuum, etc...

That flex fan will only rob power at higher rpm, I wouldn't worry about that until you got the motor running right.

I think that 302 with a 4 spd is plenty of motor, even for a 3/4 ton. It could be anything causing it to run bad. Fuel filter, fuel injectors, fuel pressure regulator, ignition, faulty emmision control devices. It's hard to tell, Is there any other symptoms you can tell us about? Bad EGR system will cause all kinds of problems. Oxygen sensor could be bad. There's just tons of stuff.

You don't need cats or smog pump for the EFI, you do need the O2 sensor, that's all you need in the exhaust for the EFI to work properly.

 

I set the timing to the 10 degrees BTDC. Thats what the sticker says it should be. When I plugged the EGR it has alot more power than before so I am guessing the EGR valve was bad. Oxygen sensor I am going to replace soon but I don't know if it is actually bad or not. I checked the fuel pressure and I think it was like 39-40 psi, wouldn't that mean the fuel pressure regulator is good then?

 

My experiences on removing EGRs on carburetored, non-computer vehicles is that the mixtures are too rich at cruising speeds. Don't know if this holds for EFI. Maybe the O2 sensor can cause the computer to adjust the air/fuel ratio enough to compensate. If not, you might want to repair/replace the EGR system components.

 

10* initial should work fine. Fuel pressure looks good. You can either replace the EGR valve and other defective emission controls or take them out, that's up to you. It's illegal no matter if you have emissions tests in your state or not. All mine are gone completely. I think emission controls that aren't working properly are worse than a good clean running engine with no emission controls.

Yeah, if you messed with the EGR and it changed/improved then you're on to something. Did it just start running bad? Is that why you replaced the spark plugs? What did the old plugs look like?

If the motor has been somewhat negleted or allowed to run poorly it can surely plug up catalytic converters. If the motor burns oil, runs rich, leaded fuels, or fuel additives can easily trash cats. If you were wanting new exhaust anyways, you might start off with a nice simple dual exhaust and go from there. Definately get the platinum plugs out of there, I've tried them on 302 motors from carbed 1982 models to HO EFI 1991 and they don't work well at all. You need a good old fashioned copper core resistor plug.

You might do some sensor checks. Alot of them can be checked with a multimeter. I'd highly recommend getting a repair manual for your truck. It will have alot of the test procedures for various sensors, throttle body, etc...

Where do you think this clicking/ticking noise is coming from? Doesn't sound like a normal poor running engine sound. Maybe exhaust leak?

You could possibly have something internal in the engine causing you problems as well. Need to throw a vacuum gauge on it, that could tell you if you have issues internally. Might be worn out cam, valves, something like that.

 

Have you checked for vacuum leaks, plug wires, fuel filter,would change the spark plugs as well to the motorcraft stock plugs, air filter, pcv valve, check the intake manifold for leaks, map sensor,

 

When I got the truck it was running okay but it needed a tune up because the guy I got it off of wasn't high on mantinence. As far as senors I borrow a code reader from school and do checkups once in while and the only codes I'm getting right now are thermactor system problem and ECT. All other senors I've checked or replaced. I did take the belt off the air pump. How do you do a vacuum test? The cat is going to come off sometime soon. Does anybody know why the platinum plugs don't work? When I got the truck I changed plugs,wires,rotor,and distribuitor cap. I changed my fan back to one with a clutch and now it runs closer to the temp it supost to. My engine dosen't burn a drop of oil. Off the line power isn't to bad it's the top end that seems to have the problem.

 

I am going to change the fuel filter but am wondering how bad would my engine run if it has a dirty filter?

 

A bad Fuel filter has an effect. I would like to know more about the "Loud Clicking / ticking sound"

You have to remember that it's only a 185hp 302, but with that said they do run well. I would make sure everything is ok (I.E. No codes, Fresh Tune...), Then attack the exhaust.

A bad cat can rattle and would definatly cause high rpm problems. Cut it off and see how it runs. The truck is old enough that it won't care that it's not there. If the cat's the problem I would put a new one on even if you don't have to. Leaving it off doesn't give you anymore power, but it does pollute more. Same goes if you put duals on. Put two basic universal cats on it.

Bigger pipes, better mufflers; they'll make more power. Beyond that it's going to cost money.

Also try 12-14* timing. Most trucks will take it, but listen to see if it's pinging (Sounds like rocks in a coffee can) Mine likes 12* and it's got more getup and go.

David

 

My timing is set to 10 BTDC with the spout disconnected, when you connect the spout it runs about 12-13 BTDC

 

He means you can run 12-14* initial (spout out) as long as there's no detonation (pinging)

I just fixed my truck, fine idle and low end, missed like crazy/fell on it's face hard throttle, wide open throttle, and high rpm. Mine was the p/u coil in the distributor, a new one compltely stopped it. Not sure if your distributor is the same as mine, just a thought.