3800Pro Forums banner
1 - 5 of 5 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter · #1 ·
I have a 97 Firebird 3.8. Did not run for 3 years. Replaced battery, starter, all fluids, fuel pump, spark plugs and wires. The motor is getting spark from all 6 plugs, fuel to the injectors and I can hear the injectors working. The car will start for one second off start fluid, then die. I also hear a hissing noise after shutoff from the drivers side of the engine bay, like its losing compression. Any advice is appreciated, thank you.
 

·
Administrator
Joined
·
1,396 Posts
Have you done a compression check? (I know that's a pain to do unless you remove exhaust mani's, which is its own ordeal). Also, the pressure built up during the first couple rotations will need to bleed off in the couple cylinders that didn't finish a cycle, also be sure to have A/C off to not have extra things happening, yet.

For a less intrusive check, you can try a coolant pressure tester (a store should have one to rent, check for videos to get familiar). This could indicate if you have a leak at an intake gasket.

Also, you can try a fuel pressure test gauge to ensure it's getting to the rail (or at least press on valve at rail after start attempt, but wrap area with rag, cuz it's probably gonna spray some gas).
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #3 ·
Have you done a compression check? (I know that's a pain to do unless you remove exhaust mani's, which is its own ordeal). Also, the pressure built up during the first couple rotations will need to bleed off in the couple cylinders that didn't finish a cycle, also be sure to have A/C off to not have extra things happening, yet.

For a less intrusive check, you can try a coolant pressure tester (a store should have one to rent, check for videos to get familiar). This could indicate if you have a leak at an intake gasket.

Also, you can try a fuel pressure test gauge to ensure it's getting to the rail (or at least press on valve at rail after start attempt, but wrap area with rag, cuz it's probably gonna spray some gas).
Sorry for the late reply, completely forgot to check this forum post.

Some things have changed since my last post:

Checked fuel pressure, 50 psi at the rail at idle
Discovered that the TPS connector had a wire that was cut, hooked that back up.
After that, it was able to actually run. It idles at 1k rpm; and if I try to give it some gas (in neutral); it will very slowly climb to just 3k then stop.
Hooked a OBD reader up to it, threw codes for the TPS, MAP sensor and MAF Sensor. I have new ones on the way.
Read somewhere that it could be a clogged cat, so I sawed off the pipe leading to the cat and nothing changed. Just extremely obnoxious now lol.

Ill grab a coolant pressure tester to find out anything I can, I appreciate it.

Let me know if any of this info gives you any ideas.
 

·
Administrator
Joined
·
1,396 Posts
Sounds like a vac leak somewhere letting lots of air in, acting like a stuck throttle?
 
1 - 5 of 5 Posts
Top