Hi,
I've been a member over on the nastyZ28 board for about 7 years & found it to be full of helpful & smart people, some smartalecs too. I'm hoping it is the same over here as I just purchased a 96' T/A WS6 for $2800. I've never worked on newer cars, most of my experience stops around 90'. I did R&R the motor & trans on my wifes 95' mini van, but that was a basic job with no modifications & I just made sure everything went back in where it came out from. So I think I can hold my own with a wrench but really know nothing about LTs vs LSs or ECUs or whatever the computers are called. I'm hoping you guys are willing to help.

The reason I got the car so cheap is that it won't start. I was planning on towing it to a dealership and opening the wallet but some of the guys over at nastyz28 recommended this site & after reading some posts I think I should be able to get her going with your help.

Here is what I know:

96' T/A with the T-56 trans has 95,000 miles. Clutch replaced at 82,000 miles. the car has been setting for about 2 of the last 3 years. the owner took it to a shop & they recommended changing several sensors which he did with no luck. he claims he changed the sparkplugs and checked for spark on each one. he checked the fuel pressure at 42#s replaced the battery. He says he used a "light thingy" to check that the injectors were working. the car does not have the alarm remote. when trying to start the car it sounds like it has a backfire through the manifold on one cylender. he said he was driving the car & it was working fine and as he was leaving from a stop sign he heard the 'pop/backfire' and it died. he has never been able to get it started since. I ran a OBD-II scanner and it returns no error codes. no smell of gasoline or vapors. he replaced the following sensors which were broke; coolant temp sensor on the water pump, crankshaft positioning sensor on the timing chain cover??, a coolant temp switch on the drivers side of the block below the exhaust manifold. it currently has no water in the car, he drained it to change the sensors. he says he checked other sensors such as the TPS with a multi-meter and they were in spec. when the key is turned on the following come on an go out: low trac, ABS, security, airbag- flashes. the following come on & stay on: low coolant, brake- I think because the parking brake is on, check gauges, ses. I see the oil, rpm,& batt needles move. the batt is at 10v but I'm sure it is because its not fully charged now. when I turn the key on I hear a whine for about 5 sec & a higher one for 3 sec when the key goes off. not sure if it is the fuel pump or possibly the radio antenna.

oh one other think he mentioned that he had to drive through a low water crossing to get to his house & sometimes the power steering would get hard. I don't think this clue has a direct relation to the motor not starting but it indicates he frequently had the engine compartment in the water deep enough to get the belt wet. I'm not sure if that is enough to create oxidazing problems on cables or sensors or with the computers.

So, what should I check?

 

Start with the basics, air,fuel,fire,and compresion. by the description of the failure and no start sound like it has fuel and a spark causing the backfire, that would lead me to think the spark is firing at the wrong time. possibly jumped time, or optispark problem.

 

96s come with obd II ? I think they came with obd II connection but its really a obd I pcm.. So you need a obd I scanner with a obd II connection. I could be wrong someone correct me if iam.

 

You're thinking of 95. The 95 f-bodies came with OBD1 and the 16 pin ALDL connector, rather than the old 12 pin. 96 was the first year for OBD2.

Miller, your problem sounds like the optispark. Since you're new to the LT1, welcome to the optispark problem, which we so fondly call the opti crap. The optispark is your distributor, and it's mounted on the front of the block, rather than the traditional location behind the intake. It's not really a piece of crap, GM just put it in a not-so-great position. But when it gets wet, it tends to do what you describe. It will give you a bad misfire, or just pop and backfire then kill the engine.

The guy that is looking at your car sounds like he doesn't know much about LT1s. If I was you, I would take it to someone that knows more about it, like the dealer. They will charge you something like $85, but they can tell you exactly what is wrong with it. Good luck!

 

Let's hear it for f-body resale value!

Sorry... one of the "smartalecs" here.

 

Good advice across the board. Yes it does sound opti-related. You may have yourself a ~$3300 runner/driver!

 

 

Thanks for clearing that up for me green96z.. Yeah get it checked by someone who has experience on lt1s not just any mechanic or like green96z said take it to the dealer. And if it is the opti heres a opti swap guide someone just posted on another topic

 

So the easiest plan is to tow it to a Pontiac or Chevy dealer and have them diagnose the car for $90. Then tow it home and fix it.

If I take it to the dealer I'll probably get lazy and have them do it.

What does a stock Optispark go for at an autoparts dealer and how much labor (hours) is involved? The procedure in the attached link seems to be in my range. I just want to be sure that it is the right thing to do before I start.

I think I'd like to give it a try myself. As I've been searching this site (instead of working today, good thing the owner is on vacation) I see a few people indicating that bad/corroded connections can be a problem too.

 

Changing the opti is not difficult. My car sat for a little over six years and needed lots of work to get up & running. I've been doing all of the work myself, and I'm far from being an auto mechanic.

There are some good contacts for getting authentic GM parts on www.shbox.com. I recommend using them as most dealers will request that you bring your own lube.

 

I took my car to a local garage and they read the codes for 25 bucks.

I also bought some factory service manuals off of EBay.

 

A stock opti will run you around $250 to $300, depending on where you buy it. There are plenty of posts on here as to which one is better, but most come up with the stock being the best for street applications. I bought mine from Autozone the first time.

The dealer wanted like $1000 for parts and labor when my water pump went out and leaked on the opti. I said screw that, bought the parts for like $400 total, and did it myself in a day. And that was the first time I had really worked on a car. It's not that hard really. The Haynes manual can be invaluable sometimes .

 

If it turns out to be your opti unit, dont waist you money on one from the local parts store, almost all of them are remans for around $120.00 that dont even come with the cap or rotor, a seperate cap and rotor are about the same price. you can buy a new ac delco unit completely assembled for $310.00 from summit.

 

So, Is there any test I can do to confirm the Optispark is bad or is this a decision you all make based on experience? I know it is impossible to tell without actually seeing the car but will anyone venture a guess as to the odds that the motor will fire if I change everything from the Optispark to the spark Plugs.

While I've done the work to pull it out of the way is it worth it to put on a new water pump too? Are there any pumps that are better than stock? This car will be my daily

 

If you end up changing the distributor, most people would probably also recommend changing the water pump, unless you know for sure that it's fairly new and in good condition. I changed both components at the same time. It would probably be a good idea to also replace the associated seals in the timing cover. I didn't change the water pump drive seal the first time around and had to go back in and replace it because it was leaking pretty bad. I went with a new AC/Delco water pump as well as AC/Delco distributor.

There are some tests you can perform on the ignition system. I'm not very familiar with them. I ended up replacing the distributor, coil and ICM, but the coil & ICM were probably fine. I just replaced them for peace of mind. Once I got my fuel issues resolved, my car would idle fine, but backfired like a **** under load. I'm confident that it was my distributor.

Read that thread I started about my car sitting for six years. There might be some good info in there. It's a ways down on the first page right now.