Intro and my trucks story

[Lukes_86]

From roughly 1986 to 1996 Ford made major strides in EFI. The early systems were called "speed density", which means that the computer uses the RPM of the engine and the density of the air to determine how much air was just ingested and, therefore, how much fuel needs to be injected. So if you changed out the cam, the intake, the exhaust, or basically anything the system was lost. Plus the interface at the diagnostic port wasn't very informative.

But by '96 the mass airflow (MAF) systems had come along and those systems took a lot more into account. You could change things and the system would still know how much air had been ingested. And the interface was a federally-mandated OBD-II port with a whole lot more information.

So keep your system stock and learn what it is trying to tell you and you can have a truck that runs very well.

Thanks for that info!

In my quest to research as much as possible about my truck and this Era of ford, I've come across a lot of info. Naturally with them introducing EFI in 85/86, there seems to be less info on forums about 302s with efi. Even the parts guy at the napa counter in one of my local towns thought I was nuts when I was explaining the intake and what not. He thought they were still only carbed at that point.

I digress. In my search, I've read alot about egr deletes and removing the thermactor, etc etc. Some people see better performance, some see worse, some are carbed some are EFI. The only one I tried was removing the belt from the Alt to the Thermactor to see if it had any affect. After driving for a few weeks, I can say that it idled and drove worse. So I hooked it back up and voila, back to normal. Why do all that work getting everything up to snuff to just hamstring myself?

I've always planned on keeping it stock but that definitely made me not want to try and "hacks" or whatever.

Don't fix it, unless it's broke.

[Gary Lewis]

Thanks for that info!

In my quest to research as much as possible about my truck and this Era of ford, I've come across a lot of info. Naturally with them introducing EFI in 85/86, there seems to be less info on forums about 302s with efi. Even the parts guy at the napa counter in one of my local towns thought I was nuts when I was explaining the intake and what not. He thought they were still only carbed at that point.

I digress. In my search, I've read alot about egr deletes and removing the thermactor, etc etc. Some people see better performance, some see worse, some are carbed some are EFI. The only one I tried was removing the belt from the Alt to the Thermactor to see if it had any affect. After driving for a few weeks, I can say that it idled and drove worse. So I hooked it back up and voila, back to normal. Why do all that work getting everything up to snuff to just hamstring myself?

I've always planned on keeping it stock but that definitely made me not want to try and "hacks" or whatever.

Don't fix it, unless it's broke.

The EEC-IV system is pretty much all or nothing. If you take something away it gets its knickers in a twist and can even put you in limp-home mode if it gets mad enough. And in that mode you have no ignition advance so the power and MPG both go away.

The EEC-V system can be programmed and is a lot more flexible. But if you have a stock system then the EEC-IV will do just about as good of a job supplying the fuel and a change would not be worth it.

We have some info on the system in several different places:

• Documentation/Fuel & Air Systems/Carburetors, Chokes, & EFI/EFI and then the Instructions tab

• Documentation/Electrical/ELECTRONIC ENGINE CONTROL (EEC)

• Documentation/Electrical/EVTM/1986 EVTM and then the ELECTRONIC ENGINE CONTROL (EEC) section

There are more but that will get you started.

[grumpin]

Welcome!