The new optispark on my engine is running perfectly. The engine fires up immediately, idles beautifully and provides consistent power under various loads, however it is throwing immediate P1371 and P0336 codes upon start-up and even after you erase the codes! I just had Firestone service technicians try to diagnose this problem and they are stumped. They replaced my crankshaft sensor wires to my computer and threw on a heat sleeve for the entire harness believing the heat was altering OHM readings and they swapped out my crankshaft sensor but it didn't help cure the problem. They think my computer is bad although there would be clear signs of this, right? I read another post like this one with regards to both of these codes and the LT1 engine running flawlessly. Apparently the fix for this problem was swapping out the new aftermarket optispark harness for the original GM harness, although others suggested replacing the entire optispark, but with what non GM brand though.

I am thinking that maybe my K&S Auto optispark wire harness is not compatible with the computer but I have no idea what brand of opti harness to purchase, I was thinking maybe EFI Connection may be good. For an entire optispark replacement solution I was thinking of the Petris Enterprises optispark. So, what suggestions do you guys have?

 

The first Autozone Opti I bought ran fine, but threw a hard P0336 on initial start up and would intermittently throw P1371. I ended up flashing the crank sensor code out of the computer. From what I read, it looks like the crank sensor on 97 cars is only used for misfire detection. The low resolution code didn't pop up that often and I was able to get the car through emissions, but the optispark failed about eight months later.

The second lifetime replacement Autozone Opti never threw the P1371 code and ran perfectly for six months before it failed. I didn't turn the crank sensor back on to see if that code got taken care of.

No issues to date on the third lifetime replacement Autozone Opti, but I ended up parking the car a couple of months after the swap due to it losing coolant that I couldn't find. lol It was losing 1+ gallons of coolant per week, but ran perfect, didn't leave any water puddles, had no water in the oil, didn't over heat as long as the radiator was kept full, and had no visible white smoke from the exhaust. I ended up buying a giant pile of performance parts that are sitting in boxes next to the car waiting for me to get motivated to pull the motor/transmission and go through them. heh..

Chad

 

I have to use the stock flashed program, flashing the crank sensor code out is out of the question, and I would like to use the optispark I have on the engine. I am getting extremely enticed to swap my ignition over to a 24x and I just stumbled upon torque head too while looking again at EFI connections.

I seriously think the wiring harness is the problem but it also holds true that a non-Mitsubishi sensor could be the very problem with my distributor and the bizarre engine codes. There are no guarantees that even the Petris Enterprises optispark will not throw the same codes if I swapped it on today. My annual inspection is coming up next month and I need to get this problem fixed for New York state inspection.

 

I bet it is the crappy non-mitsu optical sensor. I bought a brand new opti from Autozone and after week it threw the same codes that you.

 

I am sorry to hear this. My optispark was running fine for a few days, there were no indications that the sensor was bad, even the technicians at Firestone with their best equipment didn't detect any anomalies. I can't blame the wire harness swap because the car ran fine although I did go through the idle relearn procedure on the computer and this may have been enough to start tripping everything up. I concede that if you are getting those two codes, your optispark sensor is on it's way out so be warned. The problem now arises, what optispark can we possibly use that won't throw these codes and that won't crap out even without the codes?

I am willing to take a chance on the rather pricey Petris Enterprises optispark and I will probably buy their 5 year limited warranty but the fact they offer it shows they have faith in their product and the description of their optispark construction, especially on the technical/faqs page is impressive. I was intrigued by what Pantera EFI was offering but if I can't get confirmation that his optispark is indeed using older school magnetic hall effect sensor technology then why buy it if it is just another optical LED sensor with the price of a Chinese ebay ripoff?

If this doesn't work, I have no choice but to forgo college a semester and work to pay off the modifications to convert my LT1 ignition over to an LS1 coil-per-plug distributorless system. I don't want a new car when after all this money spent, my LT1 Trans Am will be my "new car" when finished.

 

Well, my car still runs fine despite the codes and I am not trying to deliberately kill my optispark with high RPM operation but I need more time to drive around and see what it does. Do you have a genuine stock LT1? My engine is a remanufactured LT1 and this could be another issue behind the irregular readings but I am not sure. Worse comes to worse, I need a custom program tailored to the current set-up I have.

 

I wouldn't put school on hold for an optispark conversion. Just warranty one of the bad ones you already have and slap it on. You're only out $5 in gaskets. Worst case, buy another one from the parts store. Pretty sure I used a coupon and got a lifetime warranty for $129. That's cheaper than buying a new cap and rotor at some places. heh..

Chad

 

There is a big problem, I have to work now in Williamsville and then take a college course in Hamburg. I can not play games with rental cars paying upwards of $250 a week, I need to take a bus but the problem is further aggravated by bus scheduling and when I get off of work to take bus A to a station to hop on bus B to take me to hamburg and get to class by 5 in the afternoon after leaving work by 3:30 to 4 in the afternoon! I am on a strict budget now trying to build up my savings after all this b.s. with my car because everyone assumes that I am going to be a millionaire while going to college and hence, I have "rip me off, please" stamped on my head. Maybe I am old fashioned in the way I think but I firmly believe in being honest with a customer and fixing their car the first time. I wouldn't do the crap that has been done to me on other people's cars, we are talking so much lost money because some people are too damn greedy or hate their jobs that much that they feel entitled to screw over others!

I am NOT going to purchase the 24x LS1 ignition conversion as of yet! However, in the future and depending upon how reliable my optispark is, I WILL put a torqhead conversion on my LT1, it includes everything I need minus the LS1 PCM bracket but I digress. I now believe my car needs a custom tune. What do you think? Otherwise I need to pass inspection illegally for b.s. optispark codes.

 

I am researching code P1357 and I wondering if my ignition control module could be a problem. The car runs great and has full power at wide open throttle. I just can't for the life of me figure out what is going on. If I delete the codes and then start the car, the check engine light won't come on but once you turn the car off it stores the codes again and the check engine light turns back on. I don't get it...

 

I really think it is the subpar optical sensor. I took mine apart and removed the no-name optical sensor and replaced it with a mitsubishi sensor......problem solved!

 

Are you joking with me? I don't have any Mitsubishi sensors on hand nor am I able to buy them that I know of. The car runs better than it ever has before and it builds up power in higher RPM, an experience I was never able to enjoy, neither in my original factory LT1 or when I got my car back in somewhat optimal running condition with it's Jasper reman LT1. I am convinced that for three years I was running on seven out of eight cylinders given the performance I am now experiencing! I still demand more off idle torque which I wonder if 1.6 RRs would satisfy on this stockish cam but that is a future mod that I can not afford now. Anyways, the sensor is FINE! I have no misfires, no hesitation, no loss of power, no indication that my optispark is faulty.

When I delete the DTC codes and then start the car hours later, there is NO CHECK ENGINE LIGHT. I go to drive the car again, the check engine light comes on. I am almost going to throw out a paranoid suggestion and say that these codes are a part of the PCM program I have, which now has me leaning towards a custom PCM tune because I can't pass inspection because of the damn check engine light that goes away and appears under highly suspicious conditions. I have driven this car 100 miles, I should have put the new PCM through it's full drive cycles and the check engine light remains. I refuse to play games with optisparks in a crap shoot to find one that may or may not trigger the check engine light with the same codes when the one I have works just fine!

What do you guys think?

 

Are you able to get a datalog of your car? If so, I would pull one and let someone that knows what they are doing take a look at it. If you can't, it might not be a bad idea to look into it. I use Scan9495 for my car. I'm not sure what options are available for a '97.

 

Unfortunately no. I can do "simple" maintenance and "simple" modifications to make LS1 pulleys and intakes work on my LT1 (I need to take a picture to show you), but as far as computer diagnostics and electrical wire diagnostics I do not have the appropriate skills nor the training/education for it. As much as I want to go out and buy a handheld oscilloscope to see the quality of signals that my PCM is receiving, I wouldn't know how to hook it up properly and run it with the optispark on the engine and having someone crank it over.

I do have an update though... I was trying to address belt squeaking when the engine is cold, as it warms up the belt squeaking stops. After discussion with a NAPA employee it was decided that my tensioner may be going, 20+ years can weaken the spring. So, after installing an aftermarket tensioner and using a 6 ribbed aftermarket pulley for the double sided belt my LT1 is using for it's LS1 replacement power steering pulley, I noticed coolant stains around my weep hole under the water pump, right above the belt! Son of a crap, my water pump is going bad and the squeaking was drips of coolant that made it on my belt. At least now my tensioner and pulley are better suited for my aftermarket belt, BUT IT GETS BETTER! After deleting DTC codes P1371 and P0336, I tested my new tensioner and pulley by starting the car and after a two second delay before firing right up, the check engine light came on with the same two codes again. SO, if I am going to replace my water pump, I might as well replace the distributor too! So, I am doing some last minute research on the Petris Enterprises Optispark on various forums to see if I am ready to add more to my credit card debt.

I really do love my car to have to put up with this...

 

Looking at DTC0336 in the factory manual, there are three signals involved with this code. High res, Low res, and the CKP sensor. When the CKP sensor goes low, the PCM starts counting the high res pulses until the next low res pulse is detected. A calculation is performed to determine the camshaft position relative to the crank. If this value does not meet the min/max spec values(outside -10/+7 and is inside -21/+51), the code is set. The scan tool PID monitoring this value is "CKP:Lo Resolution Angle".

The DTC0336 troubleshooting table asks if DTC 1371 is set....if so, then troubleshoot that code first.

DTC1371 is set when there are high res pulses but no low res pulses.

Based on the info above.....the PCM is not receiving any of your low res pulses. You either have a Opti sensor problem, PCM problem, or a wiring problem.

The first thing that needs to be done is to carefully back probe the low res signal wire at PCM to see if the low res signal is present. If not, then troubleshooting must be done to find out why the signal is dead. Could be a bad sensor in the opti, the signal could be pulled low/high before getting to the PCM(wiring fault), PCM could have a fault pulling it low/high, etc, etc,

If the signal is present, could be a bad PCM input....but the counts of the signal must be analyzed as well to see if the sensor is working right for a given RPM.

If you just changed the opti....without those codes present....chances are pretty good the new opti is to blame...however you need to verify the issue and not just throw parts at it.

Bottom line here is that you need to find a tech that knows what he/she is doing with the proper equipment to look at the signals.

Is your cam stock?

 

I just received my Petris Enterprises Optispark today and it will be installed this weekend, along with a replacement water pump.

As far as the cam, the engine is a Jasper reman LT1 so I can only hope that this engine was a decent specimen for their "reman" work and the camshaft used is made to factory specification. There is always the chance that this engine was bored to 355 but I couldn't tell you if it is. I am not even an amateur in the world of grease monkeys.

 

Didi you get the car put back together?

Mike

 

As of yesterday my Petris Optispark is installed. I had to make a special request to get their two-tone red/black cap which comes with the earlier spline drive opti since they sell only a solid black cap for the pin drive opti that I have. It looks sweet like an MSD cap but better! I tested it with a short 10 second run with the coolant system disengaged and empty and my cooling fans removed and unplugged. I had my air cleaner system with MAF and plugs all plugged in to help with the start up and on the first try as I let off the starter the engine caught and fired right up smooth as could be and smoother than my other optispark with a nice crisp idle. So I feel my installation was spot on proper. I did not take apart and inspect the optispark which will automatically void the warranty naturally but I did put ample dielectric grease on the connected plug seals and where the wires enter the plug, the cap and unit seals where oil/coolant can make their way through on top of coating the casing for the plug wire connectors. If I have any foreseeable problems with my water pump in the future, coolant spills should not be an issue.

The waterpump is a Chinese made AC Delco so God help me, I used the tacky red gasket sealant thanks to advice from a NAPA salesman who swears by it after 30 years of use with no leaks but I was forced to use RTV gasket maker for my thermostat housing so I am waiting for the full 24 hour curing period to test my handiwork with everything else back together. I had to get a billet power steering pump pulley which I found online since the LS1 pulley idea is not working and the shaft length being the biggest problem of it. So, all I have left to do is to install a JEGS oil/air separator (catch can) for my PCV system since my factory tube connectors were dry-rotted to hell allowing for vacuum leaks on top of some other miscellaneous things and hopefully this will do it, I will have my car back leak free, performing much better than before, and with a plethora of new components and a slightly lighter accessories pulley system.

 

Update:

Optispark works beautifully. I had a small leak from my bottom hose to the pump so I had to adjust my clamp, an easy enough fix. Started the car again and no codes but I have run into another problem, the car is overheating and I suspect the RTV sealer is holding back the thermostat. So, I am waiting for the car to cool down, will drain the radiator again and pump out as much coolant as I can from it to protect the opti during disassembly of the thermostat housing. I was able to find a do-it-yourself Felpro gasket kit from an autostore so I am to stencil my housing and use the now reliable red gasket sealer for my thermostat housing. I also picked up a fail-safe thermostat which locks in the open position in the event of failure so hopefully tonight this car will be fixed and PRIMO after all this money, time, frustration, fear, and stress. The gasket sealer don't need 24 hours to fully cure!

 

The stat required for your car has rubber gasket that takes care of all the sealing. You shouldn't put any RTV sealer on it. If it has RTV on it, clean both surfaces to be free of ALL existing RTV. Install new stat, and put 2 bolts back on holding the stat inlet tube.

A standard SBC stat will not function correctly, it has to be a stat for a reversed cooled LT1 motor.

Glad to hear you got the car running and no codes, I guess the Petris opti was worth the money!

Mike

 

As I suspected, while the RTV gasket maker had cured to a perfect rubber gasket for the thermostat housing flanges it had also expanded to hold down the thermostat from popping up to allow coolant to flow. Fortunately it wasn't a horrible disassembly and to try to peel off the rubbery RTV but for the stuff really glued to the upper thermostat housing, some mineral spirits was quick to remove it. Now, it took a good hour or so of cutting and trimming the do-it-yourself Felpro gasket stencil I made to clear the thermostat seal on my already mounted water pump and then to use the tacky red gasket sealer to hold down my newly created gasket and to carefully put some on the upper housing flange away from where the thermostat seal will seat when in the up position.

On the first heat up of my car for 20 minutes there were no leaks from the thermostat housing! However, once I shut my car down I had a decent leak coming from the passenger side of my water pump. I found it coming from the topmost bolt so I was able to tighten it down less than a 1/4 turn with the open ended side of a wrench but the leak stopped. For everyone to know, I did totally coat the bolts with the gasket sealer as well, it helps! I fired the car up again and there was no leak. So, for future reference for anyone who is reading this, the gasket on my water pump on the passenger side probably needed to expand and contract under the pressure to seat itself properly and keep out the coolant.

I drove my car 11 miles to get Ethanol Free gasoline at midnight and there were no signs of leakage after I got done pumping the fuel. I drove 11 miles back home and the car has sit for a few hours in the driveway and no signs of coolant leak! The check engine light never came on and I am VERY HAPPY with my Petris Optispark! The idle on my car is smooth, more noticeable than with the other bad optispark. Furthermore, if my vacuum lines to the opti were bad or coated with oil over the years of use, the brand new vacuum lines supplied with my Petris optispark helped to make the difference! You have to swap over the original factory plastic hose covers but the lines are brand new and with my Jegs air/oil separator for my PCV system, it should make all the difference now!