Hello! I thought that a stock 4.9L 300cid inline 6 was supposed to get better fuel economy than this. I was thinking around 14?

Unfortunately, I got 10MPG on the first fill up and 8MPG on the second.

I think it's a variety of things causing this (in no particular order):
* Engine temp is always "cold" it barely ever rises up past the coldest end and when it does the highest it ever gets (even in traffic or on the highway) is to the coldest line in the "normal" section. Would the engine running too cold cause this? Does this mean the thermostat is bad?

*I think the ECM is faulty because it's 25 years old and I've replaced capacitors on desktop computer and server motherboards and power supplies much younger than that... And a normal desktop computer doesn't get banged around and have such heat/cold cycles!
Reference:
https://www.ford-trucks.com/forums/1...e-problem.html
A9x ECM's (and same years ECM's) Failures Due to Age

The only reason I have not yet checked/repaired ECM is I can't get it out. I think I have located it (passenger foot area) but I don't know how to remove it? Honestly I haven't tried very hard as it's been rainy around here and computers and water don't mix, but I'd like to take care of it at some point.

*Apparently my "timing connector" is "disconnected"? Huh? I have found some references online to a "spout" connector on these engines. I'd be more than happy to open the doghouse and reconnect it... But what do I reconnect it to?

___

Could any of the reasons I mentioned above cause the poor fuel economy? And are there any other things to check? Because at this rate I need to buy a Prius

PS: my Ford has 222k miles on it. So I understand I might not get "new" fuel economy, but 8MPG is just horrible! My friends 9 ton 7.3L powerstroke F550 bucket truck gets 10-11 and he's got 4:88 gear ratios...

Thanks for any input! Would really appreciate your knowledge in keeping my van on the road.
Regards,
Michael

 

Any and/or all of the above. Have you pulled the codes? All systems on an EFI must be operating properly or the ECM (even if it is good) just won't operate properly especially if it is receiving poor or no information from the sensors.

 

Hey, thanks for the reply! I think I should start with "connecting" the timing connector. It seems like a sensible first step. I was shown the connector by a mechanic - where do I connect it to?
Thanks!

PS: As far as the codes, The "check engine light" is not on. Would this be a good device to read the codes? (I have an OBDLink Bluetooth but this vehicle does not have OBDII lol)

 

Can you post up a picture of the connector? Someone should be able to tell you where it goes.

 

Everything looks different when it's dark and raining and you're cold and want to go back inside, but this is what I got Thank you!

 

shovenose,


Do you reside in an area where the vehicle has to pass emission inspections? If not, you might get some ideas from my personal experiences in the quest for better gas mileage. By the way, my first two tanks were something like 8 and 11 mpg [YUCK!!!]


Here is a link: https://www.ford-trucks.com/forums/1...-9l-300-a.html

 

Hello,
Here in California we have some of the strictest emmissions requirements.

 

I'm having a hard time seeing what that connector really looks, but it *almost* looks like a fuel-injector connector?? If by chance it is - maybe you're only hitting on 5-cylinders?? If it actually is the "spout" connector (or timing connector) - it appears to be missing the "spout", which is a small plastic jumper that connect the two leads together. What this does (at least on my EFI Mustangs) is allow the electronic distributor timing-advance to operate. When you want to set the timing, you pull the "spout"/jumper out to remove all electronic advance so the base-timing can be accurately set. Once your base-timing is set, you plug the spout back in for normal operation. If you run without the spout plugged-in, your timing will always be at base (like 8-deg BTDC) and never advance (to 30-degrees or more BTDC) like it should and cause the engine to run really weak. This would certainly hurt your mileage...

 

Hey, thanks for your response The vehicle certainly is running poorly.

Is this the right one?
http://www.ebay.com/itm/1986-87-88-89-90-91-92-93-94-95-FORD-Mustang-5-0L-Spout-Connector-DISTRIBUTER-/321612067543?pt=Motors_Car_Truck_Parts_Accessories&hash=item4ae192b2d7&vxp=mtrSeems kind of expensive for something I could do with a paperclip, maybe I can find this at picknpull?

 

Yeah - that looks right, and you should be able to test first with a home-made jumper - as long as you verify that is indeed the spout/timing connector. (You don't want to jump it and risk maybe frying something if that's not timing connector.) And if you have easy access to a "yard" I'd think you'd be able to find one...

 

Pick'n'pull is not that far however since I only get 8MPG I am probably better off buying the eBay one if it's correct. Let me try to get a better picture and better idea of the layout near that connector to make sure it's not something else.

 

This connector should be close to the distributor harness...

But would not advancing the spark cause such horrible fuel mileage?

I would also check the Oxygen Sensor. If the computer doesn't know what's going on, it will dump fuel in in a limp home mode.