Seems like misfire. All of a sudden !!! Very extreme misfire. Almost died. I’ve
Replaced 6 spark plugs and plug wires, as well as a top wire ignition coil on my 3.0 L V6
engine. Misfire at idle and slow speed (sometimes). Runs best at higher speeds (65-70 mph). Mileage 160,000. Serviced regularly since new
CEL on??
Fords are known for bad fuel pumps and the fuel filter (cause of a lot of pump failures) needs to be replaced ever 15-30K miles…
EGR sticking open, replaced lots of EGR valves and DPFE sensor and the DPFE hoses inner liners come apart and clog the DPFE sensor, also the EGR ports get clogged with carbon…
Compression test??
Possible fuel injector(s)
I had a similar problem recently on my much older Ford truck. 302, carb’ed. I thought it was spark problem, but spark improvement work didn’t help. Further work proved it was a fuel problem, carb’s idle circuit pathways needed a cleaning. Your truck is fuel-injected, but problems with low rpm operation could still be fuel related. The low rpm aspect makes me guess this is caused by unmetered air getting into the engine somehow, vacuum leak, split in intake air path boot, etc. Engine is running too lean at low rpms.
Your truck is OBD II presumably. So a misfire should turn the check engine light on, and post a diagnostic code. Anything like that happened? Your truck’s OBD II engine has the capability to calculate fuel trim & display via a scan tool, so that’s worth checking too.
The above post about the DPFE gadget (which I think is the EGR modulator) is a good idea too, pretty common problem w/Fords of that era according to posts here. OP can use the forum search feature to see what others have said here , link upper right this page.
Can you expand on that? I have only had Fords ever since I purchased a 1984 T-Bird (used-52000 miles) in 1986, all I drove over 125,000 miles, never changed a fuel pump. My 91 Mustang 4 cylinder, had a noisy pump but did not fail, drove it for years, traded it in around 150,000 miles.
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Yes, be glad to…
Ford recommended replacing the fuel filter every 15K miles back in that era, I replaced many many fuel pumps on Fords and GM products, it was common knowledge at least in my area of the world… I of course always replaced the fuel filters but I also checked them and most were very restricted and full of sediment… When the pumps would start having to strain to overcome the restricted filters they would start to overheat and Fords would get very loud before they died…
If the fuel system was serviced regularly then yes the pumps would last…
I even towed in a Taurus wagon with a badly leaking power steering pressure line leaking one time, when I started it to find the leak I noticed the fuel pump noise and informed the customer… Well once the PS line was replaced when I went to start the vehicle it didn’t start… Fuel pump died while on my lift… lol
Thank you.
On the 91 Mustang I did have an independent shop replace the external filter around 60,000 miles, but not on any of the other cars.
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