i recently bought an 88 with the I6 and while driving and just maintaining speed it sputters and misses but during acceleration it is very smooth.. i was thinking fuel pressure regulator. what about you guys?

 

Since you just bought it, check all the regular tune-up items first. Spark plugs and wires, distributor cap and rotor, fuel filter, PCV, etc. It could be a plug getting a weak spark, but it's masked at higher RPMs.

 

I have the same problem man I did all the main things timing, spark plugs, Fuel filter even new computer, distributor all that and still having the same problem. Injectors maybe? It is bothersome because not having everything working correctly is not cool. I just traded my '87 250 6.9 international diesel for this '91 150 and it's bugging me because my old truck had 100,000 miles more and never had any issues the eight years I had it.

 

Have you checked for vacuum leaks?

 

I have had the same problem in my '89 and came across this video. I have done all the tune up stuff: plugs, wires, cap, rotor... Still had the same sputter issue. I came across this video and am going to try it this weekend. I'll let you know how it turns out.

 

So, I just replaced the throttle body gasket like in the video. My truck is running better than it has since I bought it 3 years ago. The gasket was $8 and start to finish it took less than 2 hours. It would have been quicker but i took the time to spray out the throttle body with carb cleaner and let it soak. The only thing I would add to the video above is that the torque setting for throttle body nuts is 16-18 per my Chilton's manual.
Good Luck!

 

+1 x 100

 

I blew $500 replacing everything fuel and spark related on my old 1990 with the i6.

After going all the way through the engine I fixed this with an 11 cent body washer i found at a hardware store.

The issue was that from the factory they dumped way to much egr back into the intake.

So i googled and found out I was not the only one. Trust me and try this first.

Unplug the egr vacuum line and plug it with a screw for the test. Then go for a drive. If its fixed then here is what you do.

Get that 3/8ths body washer and open the big nut on your egr valve. Place the washer inside and boom. home made fast fix egr restriction plate that inspection will not see. Keeps the cpu light off and still gets decent egr for good fuel milage.

I hope my nightmare experience turns into your instant dream fix.