GM Tech 1 Substitute?

[Bull]

The troubleshooting section of my FSM for my '95 Roadmaster makes constant reference to a "Tech 1" scanner tool. It's all over the charts showing you plugging it in here, reading values here, applying voltages here etc.

I do not have such a tool, and I see on eBay that even used ones are way more than I want to spend. What are my options?

This is a question born of ignorance. I do have a DVOM and a PowerProbe 3, if that helps at all.

I have an apparent fuel pump issue and also a stored trouble code (73) for transmission line pressure, both of which need to be dealt with.

 

[redwrench60]

I'm afraid any real Tech 1 substitute would cost as much or more than a Tech 1, but I think you can figure this out without a scan tool. You're sharper than you think.

Start with the basics. Are you sure it's lack of fuel keeping it from running? Some of those pumps are whisper quiet. Easy shadetree test: squirt some flamable sauce in the TB and see if it hits and dies.

 

[Bull]

Aside from not hearing the pump, absolutely no fuel comes out when I depress the Schraeder valve on the rail behind the manifold. I don't understand why it's bone dry when the car was running just days ago...the line should still have pressure.

Fuel gauge reads around 1/4, IIRC.

 

[nicksnothereman]

The troubleshooting section of my FSM for my '95 Roadmaster makes constant reference to a "Tech 1" scanner tool. It's all over the charts showing you plugging it in here, reading values here, applying voltages here etc.

I do not have such a tool, and I see on eBay that even used ones are way more than I want to spend. What are my options?

This is a question born of ignorance. I do have a DVOM and a PowerProbe 3, if that helps at all.

I have an apparent fuel pump issue and also a stored trouble code (73) for transmission line pressure, both of which need to be dealt with.

I got one of the performance oriented "substitutes". Wouldn't help you. You can probably get away with just using a regular obd 1 (I believe it would be obd1) scanner.

Based on the year it's probably just a bad fuel pump (unless it's already been replaced in the past). Transmission line pressure code could be a couple things usually not a transmission filter though; I avoid transmission issues honestly.

 

[krdiesel03]

Do you know is your buick is OBD1 or OBD2? I have a OTC 4000 that should work if it is OBD1 that I used on my GN for $150 plus shipping. PM me if you are interested.

 

[TinKnocker]

A 95 lt1 is obd 1.5. it is an obd2 connector within obd1 computer behind it. They ****.

 

[firebox40dash5]

A 95 lt1 is obd 1.5. it is an obd2 connector within obd1 computer behind it. They ****.

Oh god... I hate those things.

Do they use the same injection system as the '95 4.3L? I had one of those throw me for a loop a while ago. Bastid had "great" fuel pressure, like 55-60psi or something... except it wants something like 65-70psi, and it flat would not stay running off what it had. Ended up doing a fuel pump, then kinking the return line at the tank putting it back in and having it run like **** with 80+ psi.

Took me a good long while to figure out just how to get into the computer as well.

 

[RM209]

Aside from not hearing the pump, absolutely no fuel comes out when I depress the Schraeder valve on the rail behind the manifold. I don't understand why it's bone dry when the car was running just days ago...the line should still have pressure.

Fuel gauge reads around 1/4, IIRC.

Bull: I had exactly the same problem of no fuel pressure on my '95 Buick Century. I began the troubleshooting process by checking for power at the pigtail underneath the car where the power from the car connects to the line from the fuel pump. If you disconnect it and turn on the ignition, you should find voltage coming from the electrical harness. If no power, at least that means the problem isn't in your fuel pump, and won't need to drop the fuel tank. If no power, check the main fuel pump relay in the engine compartment; some of the Buicks of that vintage actually have a pigtail that is intended for bypassing the fuel pump relay. If you power that pigtail and still no power to the fuel pump, there is a problem somwhere in the electrical system; in my case, there was a corroded wire a few inches from the fuel pump relay. It sounds easy now, but I needed a bit of help from my buddy, who's a GM tech. If you want to try and shortcut the process, begin by just checking for corroded wires near the fuel pump relay.

BTW, those OBD 1.5 scannners and diagnostic tools are obsolete; if you can find one on C-L, you can probably buy it for peanuts. No doubt there are tons of them sitting in GM dealerships across the country just gathering dust.

Good Luck!
RM209

 

[Nick Danger]

You probably know how to pull the trouble codes from the climate control computer of the Roadmaster. But just in case you don't, the instructions are here.

If you don't hear the fuel pump, it's most likely that. Like RM209 says, I think you can jumper the fuel pump to test the it.

Make sure you get the correct fuel pump if you go to NAPA. I bought the store-brand pump two years ago, and it didn't fit. I returned it for an AC Delco. Their cross-references might still be wrong.

Take a look at this thread if you're pulling the fuel pump.

I don't know if you can buy replacement gas tank straps for the wagon. When I dropped the tank a couple of years ago, those were one of the rare parts.

 

[gungatim]

I have a '95 LT1 vette, same setup, OBDII connector but OBDI protocol. You can buy a special adapter cable around $35, and download scantune or other free program to your laptop. That is the only real option on these 1 year only cars. or as posted the Climate Ctrl or DIC will show codes and some sensor data.