Engine wants to hesitate

CRAIG CARLSON

MEMBER
2000 FORD MUSTANG
2.3L
V6
2WD
MANUAL
90,000 MILES

Going up a hill in fifth gear doing 80 the hill makes the speed slow down and the rpm's drop, so I drop to fourth gear and punch it. At 3,500 rpm's it just hesitates so bad I have up-shift back to fifth to get it to run right, but I was going 75. Now I am doing 40 and I almost run over on the freeway by people doing over 80. I limp to the top of the hill and then punch it and it runs fine. I was at a light and ran it through the gear getting it over 100 and runs perfect. I have a 4,000 mile old brand new engine, new fuel pump, new darn there everything. Had it to the shop that did my engine now five times for this. It does it with less than quarter tank and a full tank. Sets of no codes.

Saturday, January 25th, 2020 AT 8:33 PM

2 Replies

JACOBANDNICKOLAS

MECHANIC
110,114 POSTS

Hi,

Has anyone checked the catalytic converters for partial plugging? They can cause a power loss. Also, do you have a live data scanner? If you do, let me know what both the short term and long term fuel trims are.

As far as the catalytic converter, take a look through this link and let me know if it seems to mirror what you experience.

https://www.2carpros.com/articles/bad-catalytic-converter-symptoms

Also, here is a link that explains how to test the converter:

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

Let me know. Also, I will assume that even though the fuel pump is new, that fuel pressure was checked.

I will watch for your reply.

Take care,
Joe

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Saturday, January 25th, 2020 AT 9:23 PM

SCGRANTURISMO

MECHANIC
4,897 POSTS

Hello,

This could be a number of things. So in the diagrams down below I have included a list of systems and/or components to check from the vehicle manufacturer for poor engine performance. Please go through this guide and get back to us with what you find out.

Thanks,
Alex
2CarPros

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