Dies at closed loop?

[tpaul]

My 85 GN dies as soon as it enters closed loop. Engine has less than 500 miles, ran smooth until just the other day. New ECM, Ign mod, coil pack, plugs, wires, etc... Fuel psi is good. Numbers look good on Turbolink. Voltage is good, brand new battery, Hi-amp Powermaster alternator has 100 miles on it.
Engine runs like a top until it hits closed loop! All the numbers look good, so what could cause this problem? Before this problem started, I replaced the power antenna. Would any of the modules on the right side fender cause this problem?

 

[novaderrik]

check the wiring going to the temp sender in the intake- if the wires get shorted together, it will cause it to run like crap or die when it warms up.

 

[tpaul]

multimeter says no short... anyway to test the temp sensor? Sensor is new, but is Chinese made!

 

[novaderrik]

don't rely on the mulimeter- look for exposed wires where they go into the terminal. the insulation on the wires on my car actually shrunk and exposed about 1/4" of each of the two wires, which would cause them to make contact when the motor was running and run like crap after it warmed up.
i first found it when i rested my hand on the sensor when i was doing something under the hood while it was idling, and the car almost died.
my fix was to wrap some good electrical tape around each wire- the kind that stretches and molds to itself- then wrap a zip tie around the tape to keep it in place.
no more problems 4 years later...

 

[tpaul]

Okay, wires are good. Still having the same problem.
EGR - Good
New silicone vac lines - no leaks
Replaced IAC valve with known working unit - no change*
Intake past MAF - no leaks
Swapped ECM and chips - no change

*IAC values change in T-link with the swap, new (used, but cleaned) valve was running around 8 -10 instead of the 20-40 I was running with the old valve. Went back to the original valve T-link was reading around 80, no matter what I did to it. Replaced again with the new valve and was running the same numbers. I adjusted IAC and TPS and could never get it back down.

CAR STINKS!!! So I had to do the work outside of the garage. This has been a problem since I gutted the cat, but worse lately. Even a strong smell from the engine compartment. Should not be an exhaust leak, but that's the next hurdle down the track.

Then as I had given up, I started the car one last time to see if it would happen again before I parked it. I let the car run for an hour and it never entered "closed loop."

The "open loop" issue may have been a problem for a long time and I didn't realize it. I know the car was running in closed loop with the new engine, however I remember seeing moisture from the exhaust all the time on the old engine. That's one of the reasons I replaced that engine (plus a constant knock from the low end.)

Not too much on this car is from the "old" engine. EGR and some electronics. This car had a whole lot replaced when the new engine went in.

Oh yeah, the Damn 340 fuel pump is starting to whine! That's probably a bad thing!

 

[bmackinnon]

Sounds like a bad O2 sensor.. what do the o2 numbers and O2 crosscounts look like on turbolink?

 

[RegalT-type85]

X2 on the Bad O2 sensor, i replaced mine after a strong fuel smell , i had a exhaust leak form the DP connection to the CAT, car ran crappy2. I put a NTK O2 Ran great after I have a hollow CAT as well. I'm gonna get another one(dynomax super cat) Or tureflow(allflow) cat,nothing more then a straight pipe with a Cat housing around it for show.
Shouldn't be no more then 28$ for a new O2 sensor, NTK cheaper ,Denso,DELCO should be good.

As for the whine, sign of its going out i believe. Shouln't cost more then 100 for a new pump,unless you go with the supraTT pump. Good luck

 

[tpaul]

I would have installed a hi-flow cat years ago if it wasn't for these damn Kenne Bell headers. I just can't but one off the shop floor. I moved away from the only trusted exhaust shop I knew of years ago. Hard to find a good shop now days!
Anyhow, this car is running Casper's heated O2 sensor. Voltages during "open loop" were 757-761, closed loop they dropped, however the car died within 3 frames of T-links recording. 02 crosscounts stopped reading at "closed loop" Pretty bad sign huh! Good call! Thanks!
I fear you are correct about the fuel pump whine! The bad part is the pump has less than 1k miles on it.

 

[tpaul]

Son of a bitch! Sometimes it just takes a kick in the pants to realize you have a problem. Don't know if the O2 will solve my current problem, but I sure do have an O2 problem. The AC compressor is resting on the O2 sensor. I have a set of March underdrive pulleys for this car, now I might as well put them on. I have shorter belts for that system, maybe that will solve the contact problem.

 

[RegalT-type85]

As for the O2, you mean to say you can't get to the O2? If you want a Cat i would go with Catco Catalytic Converters 6907 - Catco Catalytic Converters Universal Catalytic Converters - Overview - SummitRacing.com or Walker Exhaust 15038 - Walker Super Converters - Overview - SummitRacing.com If you don't want to run a cat but have it for lookshttp://www.frozenboost.com/index.php?cPath=210&osCsid=c83fe6e5205a63a807c40f49b289e782 this place is cool. Where did you buy the fuel pump?

As for the heated o2, when you switched to Heated, did you notice a difference? I've been thinking about getting that and the pulley kit

 

[tpaul]

I can get to the O2, it's just that I noticed the AC compressor is resting on top of it. Probably a belt that was a bit too long from my local parts vendor. No big deal, but seams like it would help lead to an O2 failure due to vibration.
Thanks for the cat info, I like the Walker stuff. I've run the Walker Super Turbo mufflers before. I'm running the Dynomax Super Turbos now (same thing.)
Honestly, the heated O2 was installed with a ton of other new parts, so I can't comment on a difference. I installed the heated O2 due to my Kenne Bell header setup. These headers will set off the service engine soon light every so often without a heated O2 sensor.
I have yet to install the pulley setup. It's been sitting on the shelf for years. You may have to sand off the powder coat around the water pump shaft. We have an ongoing thread at: http://www.turbobuick.com/forums/ho...aluminum-underdrive-pulleys-belt-numbers.html
Fuel pump was purchased from the now-defunct Ram Chargers.

 

[tpaul]

I love this group! I swapped my heated O2 sensor for a new standard Delco sensor and now the car is running like a top. Thank you guys for the input!!!

 

[bmackinnon]

Good deal! Glad we could help. Good move using the OEM AC Delco O2 sensor. Some, not all, other/aftermarket o2's are known to cause issues... no such problems with the AC Delco... plus they're cheap...:smile: