So frustrated losing interest
 

Hello all,
I am a 19997 Trans Am, it has 60,000 kms on it. Barely drive the car. In the last couple years things are going on it.

In the last year I replaced the ICM, Crank Sensor, Fuel Relay, Fuel filter, Coil, and fuel pump. This summer I start the car and it just stalls while idling (that only happened when the coil went). It would start right back up. I noticed the oil pressure gauge wasn’t moving at an idle. The car would run, then stall, sometimes cranking before fire up. The last time it started all of a sudden the oil pressure gauge started moving again. Then all of a sudden it won’t start, just crank over. I checked the coil, seems good. I changed out the ICM, and it started. So I put everything away and then go to start and just cranks no start.


I haven't had a chance (or really a want) to check for spark, or fuel pressure yet. I am just getting frustrated and uninterested in getting to it. I’ve had this car since 1997, and never had any issues, now it seems like every time I go to start it I am afraid that it won’t start or that I can’t go for a ride because it won’t last.

I have talked to some people (In Windsor, Ontario) and the mechanics here don’t have the experience or the want to even look at the car (especially LT1).

I am losing my love of my Trans Am and the want to drive it.

Re: So frustrated losing interest
 

I have come to an understanding with myself over my Trans Am WS6 that she is a financial commitment, especially to keep her driving as a daily driver and to drive her through New York State winters where we use salt on the roads which is a catalyst for rust! Fortunately I have Carwell to go to for yearly oil based "Rust Cop" treatments. The car is going to need a full tear-down, media-blast and repaint, and some cosmetic upgrades and some of my own spins on the styling that pay homage to the Third Gen F-body and 5.7L LT1 Corvette.

With this said, you are going to be forced to perform your own diagnosis on the LT1 as I have been forced to do and with enough investigation you will narrow down what is wrong with the engine. I am going to take a shot from the hip and guess that your problem may be the optispark distributor, assuming you have had moisture build-up from the car sitting and not being driven which may have now corroded the interior components. If it is the optispark then you will have a royal pain of a time finding a mechanics shop willing to perform this service since changing these distributors is a nightmare to say the least, but not nearly as bad as needing to remove intake manifolds to get to spark plugs on some newer engines from different make cars these days.

I will also guess that you may even have a worn out EGR valve if the diaphragm dried out over time and is now no longer functioning. I hope that is the case for you, something simple to fix! I had to replace my EGR valve after replacing my optispark and further diagnosing start-up problems after eliminating the spark problems.

SOMETHING ELSE, are you using ethanol blended gasoline? If so, have you stored the car with fuel stabilizer?! Another problem might be that you have gunked up fuel in your fuel system and perhaps this can be causing some problems?! I hope not because this job will require professional know-how assuming you don't have such knowledge.

Right now these are the likely culprits that come to my mind and I hope other members chime in to offer their thoughts to help you out. I know the 5.7L LT1 is regarded as the odd-ball "red-headed child" of the SBC family and when replaced by the LS family of engines. However, this engine is pretty damn reliable and for me, I have spent so much time learning about it that I refuse to put an LS engine in my Trans Am WS6 and I have had my car since 2007. I love my Trans Am and she is my hobby and an extension of me. If you love your Trans Am, don't give up on it when she likely requires some kind of fix that will be worth it to keep her driving and in your life. Okay?

Re: So frustrated losing interest
 

I appreciate the response, I will try and find the issue. I have put premium fuel in the car and fuel stabilizer in the winter, as well as adding fuel injector cleaner at least once a year. I know the opti is known to go. I have watched many video's on them. Doesn't look terrible to change, just a pain. Then what one to buy? There is a ton of buy this one don't buy this one so there is that challenge. I love the car, just finding myself more and more not wanting to get it running. These last few years have just been working on it more than driving it. Of course when I start it up in the winter to run it always starts, just in the summer it doesn't.
I will look at your suggestions and try and figure out what the issue now is, again thank you.

Re: So frustrated losing interest
 

Just as long as you have added fuel stabilizer then you should be fine. Personally, I try to buy pure gasoline whenever I can simply because I had two fuel pumps go bad over five years and the shops told me it was gunk in the tank and I drive my car year round! I have not had any issues with ethanol-free gasoline and I am even treating the fuel with fuel system cleaner just to keep my engine as clean as I can. There is a website pure-gas.org that lists all current gas stations in the United States and Canada that offer ethanol-free gasoline. Around here most sell 90 octane but I did find one that sells 91 octane and the added octane level did make a difference in my engine performance and idle and the station is a top-tier detergent gasoline brand so all the better!

Though the optispark is the prime suspect for many issues with our cars, it is not always the problem! As I stated before I discovered my EGR valve was bad after testing spark from my optispark. Which, just to state it, a simple check of the optispark is to use an inline spark tester, hooking up the one boot to, for example, the #1 spark plug on the driver side and connecting the spark plug wire to the male connector of the inline spark tester. While in a dark garage or at night, have someone crank or start the engine and if you see electricity shooting through the clear viewing panel of the spark tester then the optispark is at least sending spark to the plugs. However, if the camshaft sensor inside of the optispark went bad, then this would be a likely reason for starting problems since the computer needs the crankshaft position sensor and the camshaft position sensor to run the engine. When playing a guessing game and throwing money at the problem, often-times you just buy a new optispark when you have tried everything else.

What do you buy? I recently bought a Petris Enterprises Optispark. This company deals with Corvette Performance and even supplies parts for Chevrolet Peformance if I remember their website correctly. The owner swears by his modifications to the optispark and if you request it, he can give you a red/black two-tone cap which is otherwise color-coded for the spline-drive optisparks of the 92-94 LT1 whereas our "pin-drive" optisparks are given a solid black cap which is no different than a remanufactured brand opti. So, to ensure I feel like I am getting something special that looks like an MSD opti, I requested the two-tone red/black cap. These optisparks are EXPENSIVE with a factory GM/Delco price tag but my car certainly has a better crisp idle than it did before on a NAPA optispark I was using before that went bad because of the water pump timing cover seal slowly leaking oil into the optispark over time. Also you get brand new vacuum lines with a metal filter which he recommends checking every 3-years. A general rule of thumb is that you want either an original Mitsubishi sensor or one of equal or better quality since our PCMs were designed to work with such sensors and anything else has compatibility and quality issues! Petris Enterprises supposedly uses a brand of sensor equal or superior to the Mitsubishi sensor! You also get a standard one year warranty or can purchase an extended three year warranty. I bought the extended warranty and so far no problems!

I should also mention, as I mention to others on posts that bring up which optispark to buy or what to do to keep them from getting fluids in them, just coat the exposed seams with dielectric grease which is the same electrical moisture protection for electrical plug connections on automobiles. This trick was suggested by a member on LS1 tech whose name I have long forgotten but should exist on an old post of mine. If you ever need to change your water pump and end up dripping some coolant on the optispark, the dielectric grease coating will be sure to protect it from that coolant working it's way past the internal rubber seals.

I am glad I could help with my suggestions. I will keep on supporting you, don't give up on your car! My Trans Am took a long time to get running proper between many bad mechanic's shops and aftermarket parts I put on her that took away from daily driving performance. However, my girl is improving and the drive is more enjoyable as I finally restore her to where she used to be and keep up on strict maintenance. Working on these cars and doing what work we can on them is a bonding experience. I seriously doubt I can have that experience with a brand new Camaro which, even then, the looks of that car are like a brick trying to look curvy compared to an F-body that was designed to have curves and modeled to be sexy! Don't give up on your car! I know I would have regretted it if I gave up early on and sold my Trans Am way back when...

Re: So frustrated losing interest
 

I'm a little puzzled by the purpose of this thread. If you're “not wanting to get it running”, “frustrated and uninterested”, and don’t “really (have) a want” to do any sort of diagnostics, what are you asking for? Any approach, without some serious diagnostics, is going to turn into a costly game of parts replacement roulette. Nothing wrong with posting your true feelings, if that's what you want, but it was unclear to me what response you were looking for.

And to clarify - the PCM does not need the crankshaft position (CKP) sensor to run the engine. The CKP sensor was added in OBD-2, strictly for misfire detection. The PCM derives a pseudo-crank position from the low resolution, variable pulse length slots on the inner circle of the optical shutter wheel in the Opti.

Re: So frustrated losing interest
 

I will and want to have the car running. I'm not going to let it sit and never run. I'm just in a funk over this.

The help is appreciated and will be used to get it up and going. It's just a few years of frustration brewing to the surface.

Re: So frustrated losing interest
 

Phoenix'97

Thank you very much for the input. I really appreciate it.
So just that I am clear, when I hook up a spark plug tester, and if I have spark, the Opti is good? I plan on trying that tonight. If that fails then I have to borrow a fuel pressure gauge,
You also mentioned
"SOMETHING ELSE, are you using ethanol blended gasoline? If so, have you stored the car with fuel stabilizer?! Another problem might be that you have gunked up fuel in your fuel system and perhaps this can be causing some problems?! I hope not because this job will require professional know-how assuming you don't have such knowledge."
How would I check if this is the issue? Just if I have spark and fuel pressure, then I assume it would be this? But if it is gunked up would that effect the fuel pressure??

Re: So frustrated losing interest
 

The inline spark plug tester only lets you know if your opti is sending spark to the plugs, hence there is no internal corrosion of the contacts OR you don't have a broken rotor! I don't think this is your problem based on what you stated. HOWEVER, if by chance the sensor inside of the optispark is bad, the camshaft position sensor, this is not something you can easily test with the optispark on the engine.

Some common symptoms that the camshaft sensor in your optispark is bad is that the car will not start no matter how many times you crank it over. It replicates fuel system problems so this is where you need to be very careful on narrowing down the problem! Another issue is driving your car and all of a sudden you lose ignition and are coasting down the road, which that happened to me on the expressway and put me in a very dangerous situation. The reason the opti-failed, oil collection in the distributor over time. The same thing happened again a few months later and it was coolant that the maintenance shop spilled on my new optispark I bought from them because they installed the water pump wrong. Suffice it to say I stopped going to them!

So, if the car will not start and you have ruled out any problems with your fuel system, the likely culprit is the optispark even though it is sending spark to the plugs! The computer needs that sensor working to run the engine!


Common symptoms of bad gas in your fuel system will be fuel injector clogging which results in hard starting, stalling, rough idle, and even pinging. If you have stored your car with fuel stabilizer you should be fine, however, one thing concerns me that I forgot about. Did you run the engine for at least fifteen minutes with the fuel stabilizer in a full tank to ensure you run the stabilizer through the whole fuel system and in the injectors for storage?! If not, there is a good chance your injectors may be clogged. A clogged fuel pump would not send any fuel to your injectors and as far as fuel pressure, I don't think you would notice much of a change since the pressure would remain but it is the fuel injectors that are clogged. It is not like your car was sitting for 30 years and you never put fuel stabilizer in the tank like with some horror stories I have heard about!

Check to make sure your fuel system is in working order first before deciding to buy a brand new optispark when nothing may be wrong with it!

Re: So frustrated losing interest
 

Checking Opti cam sensor signals with Opti on engine:

4th Gen LT1 F-body Tech Articles

Yes, takes a volt meter, but multi-meters are dirt cheap.

Re: So frustrated losing interest
 

#8
Phoenix'97
Injuneer



Thank you I have a bunch of work and research ahead I guess.

Re: So frustrated losing interest
 

Put the spark plug tester on. No spark

Re: So frustrated losing interest
 

When you turn the key to “START”, and the starter is cranking the engine, does the tach needle move up to 200 to 400 RPM? The PCM gets the RPM signal from the Opti cam position module.

Re: So frustrated losing interest
 

No. It didn't move. I tried to upload a video but it wouldn't upload

Re: So frustrated losing interest
 

That would indicate the PCM is not receiving the low resolution signal from the Opti. You should confirm using Shoebox's test procedure linked in post #9.

Re: So frustrated losing interest
 

Thank you again for the input.
I don't mean to sound ignorant, I have been doing some reading (lots and lots), the PCM usually doesn't go bad on these cars and if they do then it has to be reprogrammed to the VIN for a pacific car?
I know I need to check the Opti with a volt meter, (I am not to versed in this), I am just waiting for a friend to come over when our schedules match up to help me.

So long story short, Injuneer you are thinking it might be the Opti and not the PCM? There is a ton of posts and everyone always points to the opti, I would just like to be as sure as I can before I try and tackle that job and spend the cash.

Re: So frustrated losing interest
 

The PCM seldom fails. But pulling codes would sort that out. Not starting, no spark, and no indication of activity on the tach are common indicators of an Opti optical module failure, or corroded Opti harness connector terminals, or damaged wires in the short Opti harness connector from the bracket on the passenger side of the intake manifold to the Opti.

http://shbox.com/1/evap_sol.jpg

Loss of the low resolution signal from the Opti can cause a code for that loss. Problem is the code sets based on the PCM counting high resolution pulses, and if neither high nor low res signal is present, the code can’t set. Additionally, the code does not turn on the SES light. When the code sets it shuts down the fuel system. And, issues with the signals from the Opti can cause the CKP sensor code to set, because the PCM is comparing the signals from the Opti to the signals from the CKP sensor to determine if there is a misfire, but the two signals are too far out of phase.

When your buddy shows up with the volt meter, go right to the white wire on pin B of the ICM connector. This is the wire that carries the pulse that tells the ICM to fire the coil. You want to see a reading in the range of 1 to 4 volts AC. If that signal isn’t there, the ICM can’t fire the coil/no spark. Finish checking the 4 wires in the ICM module.

Then go to checking the 4 wires on the Opti harness. The red wire on pin A is the key, because that is the wire that carries the low resolution pulse to the PCM. This tells us if it’s the Opti or the PCM (unlikely).

Re: So frustrated losing interest
 

It is not your PCM but the optispark that will be the problem. The PCM is not getting necessary sensor information to run the engine so from what you have found, it is now pointing to your distributor being the problem.

As you have mentioned, wait for your friend to help you diagnose the optispark and verify that the sensor is bad. The test that Injuneer mentions is one I was never aware of but given how often I have had to replace optisparks I would just spend the money to replace it.

I hope you get your Trans Am running again, soon.

Re: So frustrated losing interest
 

My buddy can't come. So I'm going to start taking the Opti out.

I've heard that is easier from underneath with the car up on stand? This way you don't have to take the fans or radiator Out.
I figure this way I can replace all coolant and the water pump while I'm at it.

Re: So frustrated losing interest
 

I will be glad to help you and give advice. Taking the Optispark out is not too bad but remembering how everything goes to put it back in may be an issue! I also need to warn you that will have to remove the power steering pulley to access the water pump bolt directly behind it on the right-most side of the pulley. I tried to remove the bolt without removing the pulley and ended up damaging the pulley but thank God I didn't ruin the pump shaft for the pulley. You will need a power steering pulley remover/installer kit which they sell at Harbor Freight for a cheap enough price. If you watch some youtube videos they show you how to work this kit since you won't get any good instructions on how to use it to remove and reinstall the pulley.

You will also need to remove the mounting bracket for the smog pump since one of water pump bolts is directly behind this as well. It is not that much of pain as is the power steering pulley but be sure not to lose the smog pump screws and be careful of how the bracket bolts come out because they are different sizes!

You are also going to want to check the timing cover seal for the water pump shaft. Over time they deteriorate and WILL leak oil which will cover and seep into your new Optispark. These are cheap enough to replace and if you feel yours may be showing signs that the seal has worn down and has a coating of oil I strongly recommend changing it. It is easier than you think and one youtube video made it harder than it should be to remove! I can help you with the process if you need it.

For changing your coolant, don't forget to flush the heater coil. Over time coolant will gunk up in it and since you probably never use the heater in your car but are changing the coolant I recommend cleaning out the connections to the heater coil as well to do a thorough job!

Keep us posted on your progress and don't feel shy to ask for help if you run into problems. This job can seem daunting and WILL get frustrating at times, especially with the install! I recommend using water pump gasket seal, a red tacky substance that needs to be spread lightly on the surface of where you mate the water pump gaskets to the pump. It helps with the installation and keeps the gaskets from moving. DO NOT USE RTV GASKET MAKER or any silicone based! Coat your water pump bolts and threads with the water pump gasket sealer as well to keep coolant from running out the bolts when the engine heats up. It will save you frustration and keep your Optispark safe.

There is much I am trying to remember but as I said, let us know and I will get back to you as soon as I can.

Re: So frustrated losing interest
 

Thank you for the advise. I was going to replace the seals. I think there is 3 behind the opti and water pump. I have to look up them. I never heard of removing the power steering pulley until you just mentioned it. But that's really good information too!
I'll let you know how I make out.

Re: So frustrated losing interest
 

OK so my shopping list consists of
New Opti
New water pump
Jug anti-freeze
Thermostat gasket
balance puller
power steering pulley remover/installer kit
Seal,Water Pump Drive Shaft
Distributor drive Seal
Water pump gasket sealer
Am I missing anything?

Re: So frustrated losing interest
 

I have had my opti off a few times and never have I needed to remove the power steering pulley. I use a short socket with an extension. That allows me to get to the bolt head. The pulley may be in the way of the socket for the final threads, but you should be able to turn it out with your fingers. Install would be reverse order.

Just try it yourself before removing the pulley.

Re: So frustrated losing interest
 

Before you buy the PS pulley puller, see if you can get a socket on the semi-hidden bolt. Its hard to get to, but if I recall correctly from 18+ years ago (old age is taking its toll), if you use a 3/8" ratchet, with a 6" extension (smaller diameter than a 1/2" extension), and a short socket, you can just edge past the pulley. If that fails (maybe there are subtle differences between my 94 and a 97), look to see if it might be easier to loosen the two bolts that hold the PS pump, allowing the pump to be moved slightly to the side.

You need thread sealer for the water pump bolts that go into the water jacket.

There is no separate gasket on the thermostat housing. The seal is make by a rubber O-ring that surrounds the edge of the thermostat. You need two water pump gaskets, if they don't come with the pump.

You don't need to pull the complete damper (its not a balancer) off the crankshaft (unless you want to replace the crank seal as well). You need to remove the 3 bolts that hold the pulley/damper on the crank hub. It may be hard to get the pulley off the hub - its not an interference fit, but rust may make it difficult. Shoebox shows how to use a 3--jaw puller if necessary. Do not try to remove the pulley by hitting it, or pulling on the outside edge of the pulley. You will damage the rubber ring that hold the inner and outer damper steel rings together.

Shoebox has a lot of useful info:

Cam remove/install procedures - they cover removal of the water pump, Opti and pulley/damper

4th Gen LT1 F-body Cam Removal
4th Gen LT1 F-body Cam Install


Picture of LT1 thermostat, showing rubber ring

http://shbox.com/1/tstat.jpg


Water pump and Opti factory manual diagram

http://shbox.com/ci/water_pump.jpg
http://shbox.com/ci/opti_mounting.jpg


Damper/Pulley removal:

http://shbox.com/1/pull_pulley.jpg

Re: So frustrated losing interest
 

I really appreciate the comments thank you. Hopefully tomorrow will be the day, I will update!

Re: So frustrated losing interest
 

I forgot to add 1 more comment.... it really would have been a good idea to find a way do the final verification check involving the voltages on the Opti connector and the ICM connector. And to inspect the connectors for bent pins, corrosion, and other damage.

Re: So frustrated losing interest
 

I'll check the pins on the ICM connector tonight. That is a good point. But I feel that they way it happened was the Opti failing. Just because it was running fine, then would start stalling, now won't even start. I have the coolant drained and the hoses loosen off. and the coil and ICM out of the car so it won't start now for sure, lol

Re: So frustrated losing interest
 

5 hours later and she lives!

Thank you all that supplied great input

Re: So frustrated losing interest
 

I am glad you got her back up and running! The feeling is wonderful isn't it?!


You can cut out your own with gasket maker sold by Autozone. It was a royal pain to trim and get my cut-out to fit the housing but I am glad I did it when I had to replace my thermostat. No leaks with the gasket sealant!

Re: So frustrated losing interest
 

The rubber ring on the LT1-specific thermostat provides a perfect seal. You should not need sealant or a home-made gasket. Mine hasn't leaked in 25 years. If you buy the wrong t'stat - one for a Gen 1 SBC - it won't have the rubber ring, but it also isn't the correct t'stat.

All clearly shown in the Shoebox link above:

http://shbox.com/1/tstat.jpg

Re: So frustrated losing interest
 

Sorry to hear you are having problems, it may be pointing to the Opti Spark unit, I have not read all the answers to this thread. Good luck

Re: So frustrated losing interest
 

.......

Re: So frustrated losing interest
 

Re: So frustrated losing interest
 

Have you actually opened the cap to see if the coolant is low?

If coolant is low, are you following Shoebox's procedure?

if coolant isn't actually low, the sensor is a common problem. You could try cleaning it, but that seldom works. The coolant penetrates the seal and corrodes the circuit board. Shoebox has the replacement part #.

Re: So frustrated losing interest
 

Thanks you

Yes everytime I open the cap I add some coolant. I was just wondering how many times you guys bled the air out and added coolant. I changed the sensor last year and the light never came on before the water pump change.

Re: So frustrated losing interest
 

And it's dead again!

Re: So frustrated losing interest
 

First off, don't add coolant to your radiator! Add coolant to your reservoir! Second, the hose that connects the reservoir to the radiator at the base of the cap sometimes gets kinked and pinched by the other two radiator hoses and this has sometimes turned off my low coolant light since the reservoir was not taking overflow or during cool down it was not returning the overflow back to the radiator.

Third, the sensors do go bad on a yearly basis and I have had two which literally blew out from the back due to piss poor construction. They don't make Delco sensors that I am aware of but I have so many other brands and they all were of poor quality and construction with coolant leaking from the back from apparent pressure blowout. I did splice a new connector plug on and I am going to re-crimp the wires since they may not be making a solid connection. I have been chasing this problem for three years now and my coolant system is definitely working and has no issues with fluid loss so it is the sensor or the wiring to the sensor that is now my focus.

I hope this information helps.

Re: So frustrated losing interest
 

Coolant light is off but the car is dead again

Re: So frustrated losing interest
 

Do you have any symptoms to give us? I suspect it is the optispark, again. What brand did you buy?

Re: So frustrated losing interest
 

https://cimg3.ibsrv.net/gimg/www.cam...c1eacc92a6.png
https://cimg0.ibsrv.net/gimg/www.cam...5a046f91e0.png
https://cimg3.ibsrv.net/gimg/www.cam...13d746e2de.png
I think so too. It was running great. Stopped and talked to my neighbour and stalled. Started up little back fire sounded like from the intake. Black smoke from exhaust. Then wouldn't start again just cranks.
Today I put the spark plug tester to see if I was getting spark and it fired right up. After about a half hour running stalled. Started up 2 more times stalled and won't start just cranks.
Used a Bluetooth code reader and this is what it says

Re: So frustrated losing interest
 

I'd be really interested in learning how replacing the distributor fixed an MAF code. Defies all logic, But I'm open to learning something new.