Poor MPG

[bison]

Not sure but i believe the sensor was replaced when the motor was redone. Ill find out from my mech.
Also at around 60 mph my rmp are at around 2k

If your a 2000 at 60 i doubt that your converter is locking.

 

[LS954]

funny you should mention that. The car is currently in the shop getting somethings installed and check out, along with the poor MPG and when the mech took it out for a spin he said that it wasnt locking up. Where should the RPM be at 60 MPH, roughly?

 

[GNRick]

funny you should mention that. The car is currently in the shop getting somethings installed and check out, along with the poor MPG and when the mech took it out for a spin he said that it wasnt locking up. Where should the RPM be at 60 MPH, roughly?

Well, mine is at 2000 rpm at about 65 mph. Mine locks up. Yours doesn't sound too far off.

 

[Steve V]

funny you should mention that. The car is currently in the shop getting somethings installed and check out, along with the poor MPG and when the mech took it out for a spin he said that it wasnt locking up. Where should the RPM be at 60 MPH, roughly?

Get a new o2 as a starting point,you had a bosch in there. I put in a known good delco AFS-22 that was in my good used parts pile...did not charge you for it.

The poor mpg is in the tune somewhere. The TCC won't drop it from 19 to 12,it will drop 2-3 mpg IIRC.

You should be able to get about 20 on the interstate with your foot out of it. Around town about 12.

Not sure how much mpg ported heads hurt a street car. Anybody have some data.

1850-1950 at 60 mph is what I usually see,the TCC is 250-500 rpm extra if it's not locking up.

 

[LS954]

yea the whole trip down hear i did nt get on it once, believe it or not :biggrin: . The best MPG i saw i think was about 16MPG and that was when i was cruising at speeds between 60 and 65, other than that it was about 14.

Well the O2 swap will be one of the first things i do once i get back from over seas and drive the car back up to va.

 

[Steve V]

yea the whole trip down hear i did nt get on it once, believe it or not :biggrin: . The best MPG i saw i think was about 16MPG and that was when i was cruising at speeds between 60 and 65, other than that it was about 14.

Well the O2 swap will be one of the first things i do once i get back from over seas and drive the car back up to va.

If the tcc is inop that might come up to 17-19 which is about right with ported heads,FMIC,big turbo etc...LOL....maybe Eric can lean out the chip in the around town crusing areas.

 

[it's just a six]

My friends dad completely stock 87 GN got 9 miles per gallon because of short trips,engine not getting up to temperature.

He is a retired GM mechanics school instructor. Everything was in tune & it just got bad mileage when taken for short trips.

 

[Timbuick]

My milage is equally low. I have ported heads and a cam Most journeys are fairly short. A combination of town cruise and country blasts usinig lowish boost (up to 10psi). The car is chipped for performance. Its worth noting that Eric (TT) mentions that the non-smog chips are for performance. I would expect mpg 's to drop in that case.