kmpconley

My apologies, I wasn't exactly sure on what model year came up with the computer capable of making these adjustments. I know that wasn't the case with the EFI motors when they first came out, and I knew for a fact that from 2004 on it was capable of it, but I wasn't sure if a 98 woulda been too old.

Feathermerchant

If it has a spark plug wire and timing marks you can check the timing. Even if it has no distributor of points. It could help determine what is wrong.
Yes reading codes would be helpful. Does the check engine light come on when starting the engine? ie bulb not burned out.

fordsonly

Crazy but i had the same issue. I took a battery ,fuel line a funnel,and a injector plug to make my own injector tester. Go through them all and find the bad one. Mine wouldnt even spin the tires on grass.

bigmikek

Start the truck and at idle unplug the egr vacuum line, unplug tps, and maf, try going for a SHORT( like tithe end of the lane) drive like that. What will happen is it will force the PCM to run the motor soley off the iac at idle and will trim fuel ratios off the o2 sensors. If it runs worse or not at all o2 sensors may be your issue, my neighbours 4.2 had the same issue with no code and that's how we determined the problem being o2 sensors

willy j

Have you changed your IAC. Big difference

Jbrew

That's how it's done. All you do is supply the 12 volts to the 12V VREF on the injector. There is a solution you can pump thru them as well. However, Sonic cleaning is best, as it breaks off hardening in those little injector filters. I recall there was a few great YouTube vids out there of this procedure.

But yea, injectors can make a world of difference, - like you just got a new engine or 60+ more hp lol.

Coils are like that as well. They don't have to misfire to be slow/tired. They shear, what's called turns. Turns short,= rotations, one or many that are copper winding in the transformer. Once you have to many shorted turns, you begin to experience low grade misfires. BUT, before that happens, -performance is way down. That's why it's best to change out all coils at once vs 1 or 2. These ignition systems rely on system integrity to run properly. Coils wear out over time, - even the best of them.

An Injector and coil update is THE BEST thing for these engines. At about 150,000 miles, this update will surprise you... big time!

bonefishr

Gentlemen......thank you very much for all the input! I have several possible solutions to try. I'm swamped with guests, busted central air unit, a two-stoke that needs lower unit work, and a couple loads of supplies coming in by boat. As soon as I get caught up and try a few suggested remedies I'll post an update in a day or two.


The IAC has been replaced. The plugs are new and gapped at 54. No coolant leaks. I'll have enough time today to pop out the two front O2 sensors and take it for a spin. That'll eliminate or verify exhaust restrictions.


Could someone explain how to build and use the homemade injector tester so a monkey (or me) can understand it....I'm little confused.

willy j

You tube

bonefishr

I pulled the front O2 sensors and took it for a spin. Sounds bad as*. It was a definite improvement. Still a slight hesitation when you hit the gas but much better. I'd guess the power increased from 20-30% to 70-80% of what you'd expect. Guess I'll spend the day gutting the other three cats. Good thing I've got a cutting wheel and can weld. I'll let you know how it goes.


I have another problem, just started....what's next. Brand new battery, one year old, keeps going dead. I have a serious drainage problem. I've charged it twice only to find it dead in the morning. I mean completely dead, no dome light, no horn, not even a click.

willy j

I had a similar issue back in the day, 3 batteries later I finally found out that the windshield wiper motor was shorted out