Sputtering After High Speed

[Metacom]

Been noticing a sputtering issue recently. After driving on the highway or going ~60 MPH I notice the car sputters quite a bit. I have an LT1 MAF / translator and figured the MAF might be on its way out. Replaced it with a known good one and still having the sputtering issues but only after high speeds which is perplexing to me. When traveling on city streets, no issue whatsoever.

Other than the MAF / translator and a TT chip, the car is all stock with a new fuel pressure regulator and fuel pump within the last couple of years.

Can anyone point me in a direction with this? Quite puzzled it only happens after high speeds.

 

[TexasT]

Fresh fuel filter? Injectors New? used and never been cleaned? If stock injectors as indicated you probably should look at an upgrade as 35 yr old injectors aren't exactly optimum.

 

[SCOOBY DOO]

Post your SM numbers warmed up in Park.

 

[Metacom]

Fresh fuel filter? Injectors New? used and never been cleaned? If stock injectors as indicated you probably should look at an upgrade as 35 yr old injectors aren't exactly optimum.

Fuel filter was changed within the past two years. Injectors are original and have only been “cleaned” with Techron a few times. Agreed 35 injectors probably aren’t ideal but the car only has 55k miles on it.

 

[TexasT]

I stand by my original statement(aged out on both) that those original injectors are suspect at least and the fuel filter needs changed.

 

[John Larkin]

I almost wonder if the torque converter solenoid isn't releasing after going into lockup. That usually happens around 55mph. It feels like sputtering until it releases. You can unplug it from the drivers side of the transmission and it won't lock up while unplugged.

 

[Metacom]

I almost wonder if the torque converter solenoid isn't releasing after going into lockup. That usually happens around 55mph. It feels like sputtering until it releases. You can unplug it from the drivers side of the transmission and it won't lock up while unplugged.

Sounds like exactly what’s happening. Is that safe to drive with it unplugged?

 

[John Larkin]

Yes it is safe. It just won't go into lockup. The RPMs won't drop in 4th. It will just be without overdrive. I wouldn't leave it that way.

If that ends up being the issue, use a 700-4R long plunger lockup solenoid. Best wishes.