I have a 5-speed '89 300EFI and it runs, but not very well. I bought the car about 4 months ago from the original owner and I am not sure how up to date he kept the maintenance.
What can I do to improve performance and fuel economy? I was thinking of adding exhaust and headers but I was told that the truck would sound like bees, is this true? Any help would be much appreciated.

 

>I have a 5-speed '89 300EFI
>and it runs, but not
>very well. I bought
>the car about 4 months
>ago from the original owner
>and I am not sure
>how up to date he
>kept the maintenance.
>What can I do to improve
>performance and fuel economy?
>I was thinking of adding
>exhaust and headers but I
>was told that the truck
>would sound like bees, is
>this true? Any help
>would be much appreciated.

First of all you should do a tune up! For the tune you should establish a baseline for yourself. Replace the spark plugs, change the engine oil and transmission fluid, check and see if the timing is correct. Flush the radiator and refill with new fluid. Change out the battery if its not new. Replace the O2 sensor. Take off the throttle body and give it a good cleaning (uses a sensor safe throttle body cleaner). Inflate the tires to 35psi. You may also want to change the differential fluid and put in some new 90 weight. Make sure all of the sensors are working correctly.

Now look into performance parts. Some people believe headers work for this engine others don't. If you do redo the exhaust, the sound you get won't sound like a V8 but it won't sound like a bunch of bees in a 50 gallon drum. I redid the exhaust on my truck and like the sound I got. It sounds good (engine is in good shape), good deep tone, low rumble, but it sounds nothing like a V8 for sure. Perforance will be gained if you open the exhaust and replace those two cats with a single high flow cat. 2.5" tubing is more than enough for free flow of exhaust for this engine. Adding a K&N FIPK kit will help the air intake. A MSD ignition control will help also. A camshaft will also add some extra hp and torque and improve mpg somewhat.

1994 Ford F150
300-6
Highly Modified and more to come!

 

[font size="1" color="#FF0000"]LAST EDITED ON 19-Apr-01 AT 11:09 AM (EST)[/font][p]Hey paulg, were you the one who used the Flowmaster Y-collector in place of the resonator/front cat? If so, was it the 2 1/4" to 3" or the 2 1/2" to 3" collector......I really don't feel like finding out I got the wrong one AFTER I cut the pipes at the front cat. LOL Also, did you have to "finess" the pipes at all to get them into the collector? It looks to me that there's more of a space between the pipes at the cat. than there is at the collector.

TrailDawg
https://www.ford-trucks.com/dcforum/User_files/3aaa4bac6f539876.jpg
1993 F150 2WD
4.9L-Auto
Pro-Comp Stage-2 6" lift
Auburn Pro-Series Diff. w/4.30:1 gears
35x12.50x15 General Grabber MT's
http://www.geocities.com/ProjectTrailDawg

 

Yeah I was the one who used the Flowmaster y-pipe in front of the cat. The one I used was the the 2 1/2" to 3" collector, however the 2 1/4" to 3" collector will work just as good. I actually had to install new piping from the CP headers out to the Y-pipe. If you use this Y-pipe you will have to run new pipe from the exhaust manifolds on your truck. The Flowmaster y-pipe is just a generic use y-pipe. It will not fit the stock piping that comes from the exhaust manifolds on our type of truck. You need to run new piping if you are going to use the Flowmaster y-pipe. Any other questions?


1994 Ford F150
300-6
Highly Modified and more to come!

 

*Grumble* *Grumble*
More money for custom down pipes from the manifolds
*Grumble* *Grumble*

:P


TrailDawg
https://www.ford-trucks.com/dcforum/User_files/3aaa4bac6f539876.jpg
1993 F150 2WD
4.9L-Auto
Pro-Comp Stage-2 6" lift
Auburn Pro-Series Diff. w/4.30:1 gears
35x12.50x15 General Grabber MT's
http://www.geocities.com/ProjectTrailDawg