• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

89,loses power past 3000 rpm


bajascott

New Member
Joined
Jun 8, 2011
Messages
7
Reaction score
2
Points
3
Transmission
Automatic
new fuel pump,new pressure regulator.new coolant temp sensor,timing is dead on,plugs good,wires new.yadayada
pops through the intake and has no power above 3000 rpm.
took to a mechanic and he said the cam was flat.
I honestly don't buy it....but what do I know.
I bought truck a while back from a kid that said it had a vacuum leak and that was why it ran like crap. I drove it, it had all the symtems of a bad fuel system, so I replace the above parts, it ran a little better, but it still has these problems. I have check vacuum leaks all over the intake and there are none.
I have not checked vac pressure yet, I really don't think that's a problem.
everything that is vacuum operated works like it should.
any suggestions?
it idles great,starts right up
 


RonD

Official TRS AI
TRS Technical Advisor
Joined
Jun 2, 2012
Messages
25,290
Reaction score
8,290
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
Limited RPM can be partially blocked exhaust, back pressure builds up and engine can't pull in new air/fuel mix so power starts to drop off.

If you have a vacuum gauge($25 and very good tool to have) hook it up and run engine up to 2,000rpm and hold it there, if vacuum starts to drop you have a restriction.

Coil can't recover fast enough at high rpms so spark is limited at higher rpms

Spark plugs are gaped to wide, smaller gaps are better for high rpm power, wider gaps for low rpm power.

Another Vacuum gauge test is for weak valve springs, hold engine at steady 3,000rpm
If gauge is fluctuating rapidly then that's the probable cause
If it starts to drop then restricted exhaust.

Good read here on why you should have a vacuum gauge : http://www.gregsengine.com/using-a-vacuum-gauge.html
:)
 

cocoasranger

Member
Joined
Aug 10, 2007
Messages
584
Reaction score
5
Points
18
Location
south central Pa.
Vehicle Year
1989
Make / Model
Ford
Transmission
Manual
Didn't see fuel filter on the list of parts replaced. Partially blocked fuel filter would cause all of these symptoms.
 

backerm

New Member
Joined
Feb 24, 2008
Messages
35
Reaction score
0
Points
0
Age
46
Location
Tucson, AZ
Vehicle Year
1988
Make / Model
Ford
Engine Size
2.3L
Transmission
Manual
bad egr valve?
 

Slammin Sam

Member
Supporting Member
Joined
Jul 31, 2013
Messages
174
Reaction score
4
Points
18
Location
Western Colorado
Vehicle Year
1989
Make / Model
Ford
Engine Size
2.9
Transmission
Manual
No egr on an 89 2.9
 

Sponsored Ad


Sponsored Ad

Staff online

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Truck of The Month


Kirby N.
March Truck of The Month

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Follow TRS On Instagram

TRS Events

25th Anniversary Sponsors

Check Out The TRS Store


Sponsored Ad


Sponsored Ad

Sponsored Ad


Amazon Deals

Top