Hard stall when in overdrive only+10 M.P.G.!!!! Good grief

[philosobrad]

Shaking the bugs out of the fresh rebuild, drove around locally all weekend, adjusted TPS, adjusted FP to recommendations found here. Car really evened out and was very enthusiastic that I'd started getting things right.

Here's the "but"

Drove it at speed on my 50 mile commute to work on 4 lane this morning. Filled with gas to check mileage, etc. etc.........Did fine on the way there at 65mph with cruise on, other than what seemed like a very slight rough running condition.....no SES light, A/F gauge stayed between 13.5 and 14.5 and down to 10.5-11 under boost (12-15lbs). The car really surged when it shifted into overdrive on level highway, but did fine when pulled back into drive......cleared up when boost comes on.

On the way home, however......as I was going up hill in overdrive, the car stalled HARD then settled back down when the boost came up. This happened three times, so I pulled back into drive and seemed to fix the issue, normal boost etc. The car "seemed" to get rich and the boost "appeared" to spike slightly when this happened.

BIG SHOCK was when I got it back into Springfield at the 100 mile mark and it took 9.97 gallons of fuel!! 10 MPG.....What gives?



86 T-type. Fresh rebuild,.030 hypereutectics, 110/110 cam, TA-49 stock actuator, stock downpipe, stock intake, 42.5 injectors w/casper's chip. Stock trans and torque converter.......

 

[philosobrad]

Double checked fuel pressure and TPS.......still good, seems to idle and run up fine in park.............the 10mpg is killing my afternoon mood

 

[jasper23]

shot in the dark...could it be something wrong with the torque converter not locking properly?

 

[philosobrad]

Was wondering that as well............I'm gonna leave it to the experts.

Looks like it's time to choke up the $ for a scanmaster/powerlogger/etc.

 

[turbo39151]

hows the cat?

 

[philosobrad]

Factory cat.........no idea of the condition after all these years and 80k miles. Good place to start I suppose..........That doesn't explain the hard stall though, does it?

 

[GNRick]

Shaking the bugs out of the fresh rebuild, drove around locally all weekend, adjusted TPS, adjusted FP to recommendations found here. Car really evened out and was very enthusiastic that I'd started getting things right.

Here's the "but"

Drove it at speed on my 50 mile commute to work on 4 lane this morning. Filled with gas to check mileage, etc. etc.........Did fine on the way there at 65mph with cruise on, other than what seemed like a very slight rough running condition.....no SES light, A/F gauge stayed between 13.5 and 14.5 and down to 10.5-11 under boost (12-15lbs). The car really surged when it shifted into overdrive on level highway, but did fine when pulled back into drive......cleared up when boost comes on.

On the way home, however......as I was going up hill in overdrive, the car stalled HARD then settled back down when the boost came up. This happened three times, so I pulled back into drive and seemed to fix the issue, normal boost etc. The car "seemed" to get rich and the boost "appeared" to spike slightly when this happened.

BIG SHOCK was when I got it back into Springfield at the 100 mile mark and it took 9.97 gallons of fuel!! 10 MPG.....What gives?



86 T-type. Fresh rebuild,.030 hypereutectics, 110/110 cam, TA-49 stock actuator, stock downpipe, stock intake, 42.5 injectors w/casper's chip. Stock trans and torque converter.......

When you say "stalled hard" are you referring to something with the torque converter, or a hesitation and/or sputter?

 

[philosobrad]

Hesitated all at once while under load.......then smoothed out until the boost climbed back up, then repeated the hesitation.......pretty disconcerting how "violent" this was.

 

[turbo39151]

loose the cat and check your mpg. MY GN was getting about 10 mpg as well and running like crap. I lost the cat and viola' I get about 25mpg...

 

[Pronto]

Did the hesitation happen when the converter locked up?

 

[GNRick]

Hesitated all at once while under load.......then smoothed out until the boost climbed back up, then repeated the hesitation.......pretty disconcerting how "violent" this was.

From personal experience, my car sputtered from a bad TPS sensor and a bad O2 sensor. Also could be a bad coil pack. Put a scan tool on it and see if you can replicate the problem. Others have said a bad crank sensor can do it, too.

 

[87 WE2]

Unplug the trans electrical plug, that will disconnect the torque converter for lock up then drive the car see if it still does the same thing. Plug is on drivers side of trans.

 

[philosobrad]

Bad alternator..........red top battery trying to keep up caused this.......99% sure.

Anyway, the alternator was bad.

 

[87gnguy]

I would have never thought that...

 

[GNRick]

Bad alternator..........red top battery trying to keep up caused this.......99% sure.

Anyway, the alternator was bad.

You might want to do a search on red top battery. Some people are saying that is not a good battery. Hopefully you found your problem.

 

[Chuck Leeper]

2batts I see in the "warranty pile" at the a/p store.. ULTIMA's, [red and yellow tops] and Delco side posts...Both considered "junk" by the counter people.

 

[philosobrad]

Interesting. I installed an O'Reilly's alternator late yesterday, completely charged the battery......started the car and noticed that I now have a voltage light on. Drove the car two blocks this morning and it slowly died.....dead battery. Got a jump, drove it home and here I am. Why the voltage light after installing the new alternator and fresh battery? What could cause it to drain so fast?


On a side note......this past Sunday (before the problems started) I decided to replace the defective factory Delco radio with an aftermarket unit I've had laying in the shop for a while. Went through the trouble of installing it, with the correct pigtail kit, only to find it was inop. So I re-installed the Delco, plugging everything back in, NO wires were cut during this process. Maybe this has something to do with the issues?

 

[Chuck Leeper]

I'd start w/ a check of alt output, both at the batt, and alt stud.[Should be nearly zero drop.
Check the integrity of the plug at the alt. This is the exciter circuit.
Check the heavy red wire from the alt to the batt. Is the batt end corroded down under the pos cable insulation? Is the alt wire end corroded?
Check the ground cable end, under the turbo. Loose?
Check the pos cable at the retainer loop on the frame, and at the area near the dp.
Check for battery draw w/ all systems off.

 

[philosobrad]

Thank you sir!

 

[Chuck Leeper]

1 more..

Thank you sir!

item. I just "fixed" a friend's Vette. He had the same problem. New everything.. still going dead after a full charge.
The rebuilt alt had the output stud loose in the case. I checked output.. low, to nearly zero. Pulled up on the wire.. full volts!
Took the alt apart, tightened up the internal end of the stud... WALA! full charge!
U R most welcome