ad356

so im stumped by this. i replace the opti yesterday because the car was not always starting up on the first try, lacking power, and idling like it had a big cam. it still runs like crap. i am getting both P171 AND P336 codes. i had the ignition module tested. so where do i go from here? i dont think both opti's are bad and generating the same results. i believe that P171 is a lean condition code, so what could cause that? i have been running mid grade gas in this car i dont think that would be causing all of this grief. what should i do next?

as far as starting sometimes it starts instantly and sometimes i have to try a second time.

ad356

i was looking at the car there does not appear to be a PCV valve in the valve cover just a hose that runs from the throttle body to the valve cover the hose has an elbow in the end. there is no PCV valve, this could cause a massive vacuum leak making the car run look POop

ad356

i pinched off the PVC hose with a pair of vise grips to close off the vacuum leak. it did not change anything. i cleared the codes out but now i am getting a P1371 code. what is P1371?

timnfxr

The PCV valve is on the driver's side, in the intake manifold (not the valve cover). Follow the hose from the brake booster which connects to it.

Would be real helpful if you added a signature with some fundamentals (year, trans, and any pertinent engine mods).

Injuneer

You really need to add a "Signature" so we have the info we need to help you - year, model, engine, trans and any significant modifications.

https://www.camaroz28.com/forums/lt1...nature-879835/

I can assume you have a 96 or 97 from the codes.

First - PCV valve. There is none in the passenger side valve cover, because that's not where it is located. It is on the driver's side of the intake manifold. As usual, Shoebox has the info:

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

The line on the passenger side provides filtered, MAF measured air from the throttle body. The air is pulled through the crankcase by engine vacuum at the PCV valve, to purge harmful vapor from the crankcase. It is not a vacuum line.

P0171 is fuel trim system lean, bank 1 (driver side). The PCM is adding an average of more than 22% extra fuel on that bank of the engine to prevent it from running lean. Look at fuel pressure (low, but would affect both banks of the engine), vacuum leaks on that bank, plugged/misfiring injectors on that bank, exhaust leaks before the O2 sensors.

P0336 is crank position sensor circuit performance. The indicated values for CKP are out of range. Did you do anything to the CKP when you were installing the Opti? Unfortunately, the PCM uses the Opti cam position signals as part of the CKP misfire calculation, so if the Opti signals are erratic, the code could set.

What brand Opti did you install?

Injuneer

P1371 is a problem with the low resolution signal from the cam position sensor in the Opti.

Check the Opti harness connector to make sure it is prorerly connected, with no damaged pins.

Injuneer

YES! He needs a signature.

The brake booster vacuum hose does not connect to the PCV.

Again, from Shoebox:

timnfxr

My error, thanks Fred, old age must be showing itself.

ad356

ok so i added a sig, the car is a 1996 Z28 LT1. i bought a duralast gold at autozone, the had one on the shelf and i have had good luck with most of their parts, they also will replace it in the future if it fails where everyone else has a tail light warranty. when i looked at the valve cover i was expecting to see a PCV valve because that's where they always were on GEN I small blocks. is there a way to test the opti to test if that's the cause of the grief. the cars runs almost the same with either unit so i doubt both of them are bad. i have read both good and bad reviews of autozone's parts but i personally have never bought a part there that didnt at least work for 40-50K miles, many of the parts i bought from autzone worked for me for many years so i personally have had a good track record with their parts, not so much for napa. so how do i attack this thing? maybe its the wiring going to the opti, what do i look for? what about the opti vent system could that possibly be causing a problem? i personally do not care for this ignition system. why could GM not have used a system similar to the 3800 V6 that was sold at the same time. 4 batch fired coils and a crank sensor with the coils mount at the top of the engine making repair easy?

i have a difficult time accepting that both the used and reman parts exhibit the same exact symptoms. if this system is that finiky i would like to eventually eliminate the grief. being that they only used this setup with the LT1 and abandoned it on ALL later engines, even not using the idea of the system on future engines that might say something of how bad it is.


as far as engine modifications...... i dont have a clue as i just bought this car and i assume that it is close to stock. i just want to get it running right, and it seems like allot of these cars have ignition related problems anyways. not saying the LT1 is not a great engine, it is just a great engine with a crappy ignition system

Injuneer

Given your attitude toward the Opti, you should make the Bailey Engineering LTCC swap, or the EFIConnection 24X conversion. Both will net you 8 LS1 style coils, although the Bailey still requires the cam position signa from a healthy Opti.

A lot of the cheap aftermarket Optis us a Chinese copy of the Mitsubishi cam position sensor. I don't see how you can blame GM's design on sh!tty Chinese parts.

Good luck.

ad356

i dont really like a system that's expensive to diagnose, has its history of problems, is mounted behind the distributor on an Fbody the job isnt that technically the difficult (if it was a roadmaster or caprice) but being how tight it was, that job was not fun. i was on the understanding that the autozone unit was a re-manufactured delco unit i do not know if the sensor is the failure item anyways. heck i dont even know if the unit i installed is bad, it might not be. so how much does the conversion cost?
i also do not want to replace the opti again unless i could factually prove that its bad, im not sure HOW i would do that. while the car is running i can hear a ticking sound LIKE a bad wire or something of that nature. im going to pull the car into the barn tonight and check the wires with the lights off. any arching will show up pretty quickly.

ad356

i dont think that a system that uses the opti signal would fix my problems...... if the opti is in fact bad since a signal from a good known opti is required (dont know if my opti is even bad). i like the option that eliminates that problem completely but the price is ,well a bit high. there is nothing cheap about this system, for a GM opti they are $250-$300+ and i dont think that's a local dealer part, although i could be wrong... i wonder if autozone would give me my money back, if that was the source of trouble. i will not have time to tear into this thing again until next week. i have read complaints that sometimes even GM optis are bad out of the box. i miss my HEI system. it was cheap, reliable, and bulletproof.. i think GM could have done a better job with this.

what about the vent system on my car, could that be causing my issue.

i also replaced the pigtail that feeds the opti as the autozone kit included it. i looked at the wirring harness on my car and everything is still wrapped in the factory protecting tube nothing looks bad about it. i dont really want to start pulling wires out of the tube because if they are wrapped with that there probably isnt anything wrong with it.

Injuneer

Maybe someone else can help you. It's obvious you are not going to listen to anything I say. You've closed your mind. Trade it in on a 3rd Gen.