Hey guys...

I have a 1989 F-150, 5.0, AOD, and I need help with a part name. It would be the part on the firewall that has 2 vacuum hoses and an electric plug attached. The green hose runs to the EGR valve.

Now the prob is, the EGR isn't working off the green hose. The part in question is getting vacuum from the other hose, but the part is not allowing the vacuum to operate the EGR. I tested the EGR and it is operational. The vacuum hoses are not cracked so i eliminated the possibility of a vacuum leak. And the plug seems to be getting juice so I don't think its an electrical prob.

Now to spend some money. What do they call that part? Its so small that I hope it doesn't cost much.

Thanks in advance......

 

First guess the EGR vacuum regulator, should have a 9j459 number on it.

 

How are you determining that it isn't working? The computer won't open the EGR valve at idle.

 

I agree, it is the EGR vacuum regulator.

The EEC Computer ONLY operates (opens) the EGR valve when it receives ALL of the following input signals:
* Warm engine from the ETC
* Part-throttle signal from the TPS
* Part-load signal from MAP
* Time since start, from timer in the EEC Computer

And nothing else.
Any of the sensors alone can not open the EGR.

 

One more signal, Bill. Someone else in here pointed it out to me. Speed signal from VSS. If the vehicle is not moving, EGR doesn't open, regardless of throttle position, vacuum, temperature, etc. Didn't believe it until I tried it on a fully warmed engine (just got home from a 100 mile trip).

 

Are you sure that the timer is not opening it at that point, as that one is not listed in the manuals?

 

E63Z-9J459-A .. Regulator ~ Marked: E53E-9J459-AA

Still available from Ford.

From FTE sponsor DIRECT FORD PARTS: Ford suggested retail price: $34.97 / FTE member net: $24.71.

 

From the Ford shop manual:

"The EGR system is enabled only during part throttle modes when the engine is warm and stabilized. These conditions exist after a length of time has elapsed since engine start-up, the Throttle Position (TP) sensor indicates part throttle, and the Engine Coolant Temperature (ECT) sensor indicates a warm engine. The EGR system is disabled by the Powertrain Control Module (PCM) whenever the TP sensor indicates closed throttle or wide open throttle. The disable function is necessary to avoid driveability concerns during idle and maximum power demands. While EGR gases are being introduced, the PCM also compensates for changes in the air/fuel ratio by modifying injector pulse width and ignition spark advance."

 

It may not be listed, but no way would that EGR come open with the truck sitting still. I probably ran the engine at 3000 RPM for 3 minutes or more, and the EGR NEVER opened. I did this while playing with a bleeder on the vac line going to the MAP to simulate loading (less vacuum means more load) to see if it would open. So, I marked the shaft on the EGR with some light grease, and took it for a drive again, and yep, it opened then. It may not say it, but there are probably as many different EGR strategies as there are Ford engineers. If you want 5 ONLY ways to do something, just ask 5 engineers. Maybe my ECM was made on Friday. I'm not arguing with you, just reporting my findings after being chastised about the EGR opening with exactly the same inputs you pointed to based on the Ford EVTM or shop manual. Mine has NEVER thrown an EGR/EVP code unless I disconnected the vacuum line and plugged it off. I got the CEL within 5 minutes after I started driving with a cold engine, but it went away again as soon as I stopped moving, but had not yet shut the engine off. This was a suggestion from a Ford Service shop manager and family friend when I was having driveability issues.