No power again

After TBI rebuild, AIC, TPS, fuel pump, filter, intake gasket, plugs, wires, cap & rotor,  ignition module swapped, it was running great for a few days. Back to no power from lights & hills....practically  have to push.
Usually happen after car really warms up, car runs about 180⁰-200⁰.

Going after it with a multimeter tomorrow. 

Any ideas?

Thanks Paul

anything done with the transmission recently?

when I was working at a shop had a customer with similar issue that seemed to be losing power once the car warmed up and turned out to be the transmission was failing.

also my brother had a truck that cold everything was fine, but once the transmission got warmed up he would lose reverse.

goldwolfnhn wrote:

anything done with the transmission recently?

when I was working at a shop had a customer with similar issue that seemed to be losing power once the car warmed up and turned out to be the transmission was failing.

also my brother had a truck that cold everything was fine, but once the transmission got warmed up he would lose reverse.

Only had the car 7 days. I guess it's a possibility, I'll get it warmed up tomorrow & see what a brake stand is like. 

I have to dance on the throttle to find the sweet spot like with a finicky carb.

the only other thing I could think would be something not reporting properly or you might have a vacuum or fuel hose that might be internally delaminating or collapsing when it gets warm causing a partial obstruction or restriction?

though having to dance the throttle sounds more like either still a problem with the injectors, the tps or something related, or like I mentioned above a vacuum issue, best case might just be needing to do a fuel system cleaning despite all the new components, finally got my 1989 R2500 Crew cab running again and that truck is having a finicky throttle, but some of that might be the fact that it's running on 4 year old gas, and that it hasn't run in at least three years, it is also equipped with a tbi 350 and I know when I have had throttle issues in the past it was usually due to vacuum issues.

It may be the hose between the pump and the sending unit in the tank. I realize that it is impossible to check fuel pressure on the TBI cars, so unless you can make a patch line for between the filter and engine, or between the metal line and the nylon one at the front of the engine, you must remove the tank to check it. If it is not throwing codes, that is probably the first thing I would look at. I have had similar issues whenever the throttle acts up, and it will not throw a code.

If you have access to a 90-93 Fleetwood in the local junk yard, the metal fuel pressure line has a schrader valve on it, and you can swap it directly for the one in the B body. Then you can attach a fuel pressure gauge to it. It is about the same amount of work to pull the tank as replacing the fuel line, but if you do the fuel line, you can diagnose fuel pressure issues in the future without dropping the tank as a first option. Regulated fuel pressure should be at least 9 psi, and maximum of 15 psi.

If you are going to pull the tank, and check the hose, replace the pump with a quality pump (Delphi, AC Delco) and the hose. Be careful, it is easy to knock the fuel level arm out of the clip, and then your fuel gauge will not work.

Placed pump & short hose from pump to sending unit already...NAPA. May need to pull tank again though, when I put back, fuel gauge was bouncing from half to full with only a few gallons in the tank.

Just picked up a code blinker, will try & figure that out a little later today.

Could loss of power be from ECM learning? Just a thought.

I took a video of flashes, some are so fast I can barely count them. 11:30 & never got back to the base code 12.

Make sure it is on the engine side of the switch, and not the antilock brake side.

Fred Kiehl wrote:

Make sure it is on the engine side of the switch, and not the antilock brake side.

Yes, set to ECM, not ABS.

Had to go back out & check

cagedfalcon wrote:

Could loss of power be from ECM learning? Just a thought.

I took a video of flashes, some are so fast I can barely count them. 11:30  & never got back to the base code 12.

I highly doubt it, as the ECM relearns pretty much anytime you disconnect the battery, and have no alternate power source for the ECM to pull power from and on my vehicles I've regularly disconnected the battery for prolonged periods of time and had no performance issues later.


what I find odd is you commenting about flashes so fast you could barely count them, as any obd 1 vehicle I've ever pulled codes on I've never had a problem counting the flashes, but also the length of time you seem to be implying its taking to get back to the base code might mean there is a communication issue.

What about swapping ECMs from the RMW to the OCC, is that possible?

it should be I would think as long as they have the same engine

goldwolfnhn wrote:

what I find odd is you commenting about flashes so fast you could barely count them, as any obd 1 vehicle I've ever pulled codes on I've never had a problem counting the flashes, but also the length of time you seem to be implying its taking to get back to the base code might mean there is a communication issue.

Well, after your comment about a communication issue,  I pulled ECM fuses on both cars & put the Buicks ECM in the Olds.....better throttle response, acceleration, pulls up hills now from a dead stop.

Think we've figured it out. Going to open up Olds case, I'll bet it's corroded. When I was changing power window guides, I noticed the arm rest brackets were rusty also chromed plastic switches had green vergas in them....must have set in a humid garage.

Opened up old unit & it's perfect! Just a bad chip?

Looking at codes, standard 12 w/key on, motor on & flashed very fast, blipped the throttle & just blinked at a slow, "one-1000", I counted 60+ at this pace. Must be doing this because it's the wrong chip?

Last thing....I hope.
Found the trans indicating switch just hanging under the dash. That may have caused it to be doggie.

The trans indicating switch only tells you which gear it is in. The shifter position switch at the bottom of the column allows you to start it in park and neutral.

The 93 computer is supposed to have a better fuel map in it. Other than the chip difference between the LO3 and LO5, the computers are the same.

I have just experienced having two computers act up, but happened to have a third that works correctly. The issue with the car was the MAP sensor.

Fred Kiehl wrote:

The trans indicating switch only tells you which gear it is in. The shifter position switch at the bottom of the column allows you to start it in park and neutral.

The 93 computer is supposed to have a better fuel map in it. Other than the chip difference between the LO3 and LO5, the computers are the same.

I have just experienced having two computers act up, but happened to have a third that works correctly. The issue with the car was the MAP sensor.

The lower switch may let car start in park or neutral but since I put it back on the car sure takes off & shifts better.
MAP sensor voltage checks out fine at idle & WOT or as close as I'm going to get. The IAT & water temp sender, O² is .41 are all reading correct. 
No codes since comp swap, not even a 12 while running.

you should get the 12 code no matter what as long as the port is hooked to the computer correctly, when you switched the computers did you look at the terminals on the plug aswell as on the computer, as if there was corrosion it might have been broken up enough by the removal to let the other computer get a better signal solving the problem?

No corrosion noted & I did look.
Key on, 12 code.
Motor on, no 12 code, just 1-1000, 2-1000, 3-1000 up to 60 & I stopped counting.

The codes only display when you are in key on, engine off.

Fred Kiehl wrote:

The codes only display when you are in key on, engine off.

Yes & only 12 code.....must have fixed everything!?