New Member 94 Caprice LT1

Hey everyone, I just bought a 94 caprice wagon that the previous owner started modifying and intend to make it a daily driver.

It's a 94 with an LT1 and right now it has open headers.
The previous owner re-geared it to 3.73s
He also included a TunerCat LT1 Tune kit with the cable and def file.

Right now I am trying to get some type of exhaust under the car so I can drive it and evaluate further needs. I am thinking of just putting some mufflers that exit out the sides in front of the rear tires for now.

There are no O2 sensors so I am setting up the cal to run open loop for now and will decide how well that is working before I pony up for sensors and weld them into the exhaust.

Lastly on my drive home it never warmed up so I am curious if the thermostat is stuck or non-existent.

So that is the beginning of my journey, I hope that I can share some learnings here along the way as well as learn some new things myself.

Welcome CJ!

Sounds like you found yourself a nice wagon.

Everyone learns from everyone, that's why we have a great community of wagon guys.

You mentioned your wagon never warmed up. If you meant the heater never warmed up, it could be the thermostat or a very common problem: the heater core needs to be flushed out. If you meant the engine never got up to temperature, it could be the sensor on the passenger side head.

Tom

Hi!

Thanks for the reply.  The issue is the engine never warmed up.  The sensor seems to be reading correctly based on the sensor output but the engine, hoses, and radiator were all only about 95° after a 10 minute drive with an ambient temp of about 65°

Last night I let it idle for close to 15 minutes and it was only up to 100°. I am thinking this is thermostat related but I will know for sure when I pull it out tonight.

Here is a picture for now. I will post better pictures soon.

Welcome,nice looking Caprice.

cjweinga wrote:

It's a 94 with an LT1 and right now it has open headers. ... 
  I am thinking of just putting some mufflers that exit out the sides in front of the rear tires for now.

There are no O2 sensors so I am setting up the cal to run open loop for now and will decide how well that is working before I pony up for sensors and weld them into the exhaust.

It can be done. The trick is whether the tranny crossmember is set up for duals or not. If not, then you need a crossmember that will work.   

 Dan at Clear image sells the. (made by a jobber for him, not by Clear Image. It isn't cheap, around $400.00 now. I bought one in the spring.

 You can mount an x-pipe, but keep the mufflers very short, otherwise, you'll run out of room when you try to make the turn in front of the tires. 

welcome other newbie! Where are you located?

Yes definitely run the o2 sensors.

Where are you located CJ?

lakeffect wrote:

The trick is whether the tranny crossmember is set up for duals or not. If not, then you need a crossmember that will work .

pssst,. dave,.. its a 94 ,.. LT1 car,...

Thanks for the welcome. I am in Southeast Michigan.

I did some data logging and I think he had installed O2 simulators or something because I did a scan and they are reading like .451 volts all the time. I hacked together a quick and dirty dual side exit exhaust this afternoon and went for a longer drive. The engine did eventually get up to temp but it took a looong time. On the plus side, the heater core isn't plugged as it threw plenty of heat. All in all it ran really well by seat of the pants feel. It obviously didn't have the WOT upshift lines corrected for the gears because it just bounced off the rev limiter in 1st at WOT. I have calculated the correct values to move the shifts down in vehicle speed. I will try flashing my cal tomorrow and see how it runs when forced into open loop and with EGR, AIR pump, Evap Purge, and Cat protection all disabled. (These are all removed)

On second thought, would .451 volts mean the O2 sensors are installed but not actually in the exhaust? I would assume they are 0 to 5 volts but the diagnostic probably relies on voltage never going to zero (open circuit). I guess I will have to do some digging around tomorrow, maybe they are just zip tied somewhere but I thought I would see them while installing the exhaust.

Thanks Nick, Since I don't drive one, I didn't want to make assumptions.

Update: The thermostat was indeed stuck open.

I fixed the CHMSL and rear defroster and got a temporary side exit exhaust fabbed up. It will be going into the shop tomorrow to get a proper dual exhaust to the back.

I also installed some center caps that I think really clean up the look of the wheels.

Sounds like you are making some pretty good progress. Wheels look way better. Is that a fixed antenna? I didn't know they offered a fixed antenna on our cars.

Thanks, yeah that is a fixed antenna. I'm not sure if it is stock though.

My next issue to resolve is the fact that it ran out of gas Friday, gauge doesn't work. Easy fix, I will just fill it up. Uh oh, it only took 7 gallons which means there should be about 15 gallons left in the tank. I guess I need to drop the tank and figure out why it can only pickup the top 7 gallons of fuel.

While you have the tank dropped, do yourself a favor and replace the pump.  It's not a question of if the pump will quit but when.  And the answer to that is right after you fill the tank so now you have to try to drain the tank before dropping it.

nstg8r wrote:

While you have the tank dropped, do yourself a favor and replace the pump.  It's not a question of if the pump will quit but when.  And the answer to that is right after you fill the tank so now you have to try to drain the tank before dropping it.

the OE pump is good until about 170K.   If you have only around 100K I'd leave it (unless that's the issue). Do NOT buy the cheap one, or a Bosch, they are crap.

I did a tank drop write up
https://gmlongroof.4umer.com/t1426-write-up-on-how-to-drop-your-tank?highlight=tank+drop

Sprocket wrote:

nstg8r wrote:

While you have the tank dropped, do yourself a favor and replace the pump.  It's not a question of if the pump will quit but when.  And the answer to that is right after you fill the tank so now you have to try to drain the tank before dropping it.

the OE pump is good until about 170K.   If you have only around 100K I'd leave it (unless that's the issue). Do NOT buy the cheap one, or a Bosch, they are crap.

I did a tank drop write up
https://gmlongroof.4umer.com/t1426-write-up-on-how-to-drop-your-tank?highlight=tank+drop

Lost mine at 140k

Lost mine at 87k.

 Put a drain from in it while it's out.

While it's out, check everything! I ended up doing a sending unit/pump assembly when I replaced my fuel tank due to the sending unit mounting ring on the tank being cracked. Welcome Aboard.

Well, I ended up changing everything. Someone had it out before and they must have installed it with a hammer. There were crappy crimp connectors on the harness in the tank where the spliced in a new pump. The fuel level sensor arm was broken off and the wiring was spliced outside the tank too. Additionally the tubes on the outside were so corroded, one snapped off while I was removing the quick connect fitting.

Everything works correctly now with a brand new delphi sending unit and pump.

hey guys, what is the advisability of replacing the hoses if keeping the old pump? Might extend it's life? Beautiful project!!!

Welcome and you're making a lot of progress. Being handy with the old pc helps a lot to.
Keep up the good work.
Pete