Possibly another Optispark post im sure. But car starts after about a second or so of cranking(was always like that even before problem started) and idles smoother when cooler. Once gets up to temp has a miss you can feel and intermittent backfire. In the garage my brother said it backfired once with flame out tailpipe. note these arent gunshot backfires but pops. Driving the car has a noticable miss and on deceleration or at the threshold of decelerating slowly or maintaining speed (I.E. Throttle position slightly open) car will again pop and backfire. When under load the miss gets worse. When under load car will not backfire. Right before this happened I added a bottle of lucas deep clean fuel injector cleaner and about 15 minutes after i noticed the first backfire while cruising. The problem has slowly gotten worse. I used stethoscope and listen to injectors pulsing and fuel pressure is around 33ish idle and 43 with FPR vacuum unplugged. I would probably say opti has bit it but the car will rev clear to rev limiter. I think the fuel cleaner is just a coincidence but I have put a new tank of fresh 93 in it. Datalog on car is not showing a low res or high res code. What do you all think? Opti?
Car has fairly new plugs and brand new wires along with new fuel filter. I plugged a new coil in and problem did not change so I am returning new coil.
mods are 373s and stall. longtubes, ORY, catback, and CAI. Has been tuned.

 

while it could be several things causing this...from your description (once gets to temp..) one possibility is a failing ICM.

popping/backfiring is often symptom of failing Opti. The rotor screws may just be coming out...you would need to pull the opti to see though

 

Yes, but what I've gathered on these optis is when they go they leave you sitting or something off the wall. It just has me kind of second guessing on buying the $400 opti and all that work for nothing. I've done some searching online but all the threads I find where people ask about symptoms usually has one or two posts and then the commenters start ramble on about other things. Are my symptoms usual with a failing opti? As like I said the car has no problem reving to 5800 in park, it will even hit it in gear but is down on power. Is there anyway to test the ICM? I've only seen the ICM go out maybe once and when that happened the car just died immediately and wouldn't start

 

bench testing the ICM often yields false condition (shows good) as heat is what generally triggers it to fail when it is going bad. Since you mentioned the problem seems to occur when at operating temp I just pointed it out as a "possibility".

you should get a FP gauge you can see while driving. One with a hose on it. Do a WOT sustained run and watch FP...if it drops you are going lean and that could be cause of backfire/loss of power. Your FP readings are on the low side of good

failing Optis don't always throw a code, never did for me, so hard to diagnose. Frustrating but it could be Opti related...maybe something as simple as lose rotor screws

have you looked at plug wires carefully in the dark for any plug arc??

 

unfortunately my fp gauge needs about 4 more inches on it to get it on my windshield but wouldn't unhook FPR vacuum simulate WOT? As I did this and hid the bleed valve in which pressure dropped to something like 25 and when bleed was closed it jumped right back to 43. On my datalog It says the pcm is pulling fuel trims like crazy everywhere. some short terms were at 115 and BLM dropped to 122 in spots. Because of this miss Id guess the o2s are reading half unburnt fuel vapor...Which again would point to opti, being sparking when exhaust valve is opening and igniting exhaust gasses making the backfire. Correct? and at first this was a temp thing but the miss was always there got worse as it got hot, but now its just constant really. On my datalog software (eehack) If it monitors a silent error code for whatever tick it happened in it the log will be the only spot you can find it. IF I recall a long time ago I seen a low res code but everything was running fine so I dismissed it. currently there are no codes set.
Im starting to think more and more its the opti, I dont really want to replace waterpump, but what seal do I need to get for R&R of the pump. Id guess the opti came with the seals already
Also plug wires were just installed last night

 

while your issue sounds more ignition vs fuel I was suggesting FP test under "sustained WOT" to see if FP holds. Need motor under load at WOT. FP check just at idle and quick throttle snaps won't reveal a "tired" fuel pump. If FP holds steady under sustained WOT than the fuel pump itself is good. If not the motor leans out and will pop/backfire. Was suggesting ruling the fuel system out since it is way easier to test vs pulling the Opti.....which I suspect will need to happen

Just buy the FelPro front timing cover gasket/seal kit for around $12 and any auto part store. It has everything you need for WP & Opti swap

 

At first it started I suspected the pump. But the rate at which it got worse and that it does it at idle while fuel pressure reading at 30s at idle and still backfiring and my pcm pulling fuel everywhere kind of ruled it out for me.
I look my part numbers up on rock auto and copy/paste onto Amazon just cause prices are the same and I get free 2 day shipping from Amazon prime. I ordered the E-4 torx, the reman ac Delco opti and this kit part number off of Amazon. I'm pretty sure it was correct. https://m.summitracing.com/parts/fel-tcs45956

 

There's a chance that an injector could be plugged open or closed and you won't be able to tell by listening to them. They'll still tick because they're being told to open - but nothing (or too much) may be coming out. You can pull the injector rail and see if any of them are weeping, or pull the plugs and see if any are wet with fuel.

Use an IR thermometer to see if any exhaust port has a significant temp variance from any others. If so, your problem is associated with that cylinder.

Check your plug wires for arcs. Wait for nightfall and mist the wires with water. I had a bad wire that would only act up once it was hot. Heat increases electrical resistance. What about your coil? How old is that? They also can get cranky when hot.

What is your vacuum reading at the manifold? Is it steady or pulsing?

 

I'd check for a vacuum leak around the manifold and all ports. Your EGR still functioning?

 

Could I pull the fuel rails and cycle key to watch for leak? Like I said the problem is getting worse so I wouldn't have thought fuel related if psi is checking out although I never did a leak test seeing if it held the resting pressure when fuel pump isn't running. Could I simply unbolt the four bolts and pry them both up while leaving everything hooked up? I thought the ticking was the sound of valve opening and closing but you're saying it's just the electrical click and not the actual injector pulsing? For the car to be running like this I would think if an injector it would definitely be more than a drip right? Probably a spray or squirt. But if it is stuck closed how would you tell? And if I do find out a bad injector or froze one is there any way to clean it or unstick it? Being the problem was close to immediately after the fuel cleaner it may be stuck with something. Would I have to have someone crank engine with fuel rails off and make a load of a mess to ensure proper valve operation?

Also egr is hooked up but tuner has disabled it. Has a recent egr valve so don't think it is that. I didn't find any vacuum leaks when I looked

 

The ticking is the injector pulsing which it will do if it gets the proper power. It doesnt have to have anything running through it to pulse. Its the injector opening and closing. Your PSI is a tick low, but that could be an old pump, clogged filter, or other things. Yes, pull the bolts holding the rail down and turn the key on to prime the pump. Depending on how long the injectors have been in, you may want to get new o-rings since pulling them out may tear a few. You wont be able to tell anything other than if one is stuck closed or open, or if one is dribbling. Flow-rates can't be determined by eye.

You can also pull the plugs to see if one is wet.

You won't find a vacuum leak by looking at it. Hook a vac gauge up and post the results. Also, I'd do the temperature-testing mentioned above before I did much else.

 

I don't think I have an IR temp at the shop. But I do believe I have a vacuum gauge somewhere. I do have headers so the plugs wouldn't be too much of a pain to pull. At this point I've even thought about a can of seafoam through the vacuum booster. Anything to avoid the opti(which I do believe is stock with 134k miles) but I think it's inevitable. I should have pulled them when I did the wires but after routing the mess though the passenger side I was ready to be done with it. I pulled the rail and cycled key on and all was dry. I'll try to get a vacuum test soon. Would a data log be able to tell vacuum?

 

a original untouched opti at 134k has exceeded its design lifespan. Like any distributor the cap & rotor are "wear" items and at the very least that should be replaced. The rest of the opti should be fine unless there is excessive play in the spline shaft (worn bearing).

And putting on the new "O" ring on Opti spline is advised as the original is very likely hard and flattened by now

 

Okay I just data logged the car idling and after watching it seems the left bank long terms settle in around 119-124 and right term trims settle in around 135-140. Backfiring and popping all over if I set the idle speed to greater than 1200. Seems to me like something is going on with the opti commanding fuel and spark at wrong times. Is that sound feasible? If I'm right opti tells pcm when to spray Injectors so if the rotor has come lose or shifted it has thrown the whole banks out of whack as a whole. My map pressure hovered between 30-32 kpa
I can upload log file if need be

 

As ****** stated, your opti has exceeded its designed lifespan. Had you mentioned that at the top, I'd have suggested you focus your energy there. It could easily be, and most likely is the source of your problems.

 

Yes my mistake I should have mentioned mileage of the car. And it is no problem. The opti and things don't get here till Tuesday. I've read bad things about the reman ac Delco I got but it seems thats all you can find besides the eBay listing here and there. I got the felpro TC gasket kit but would the new opti come with the O-ring ***** said I should replace?

 

YES new Opti will have new O ring on it

if your current opti turns out to be a bad Cap and/or rotor I would keep it and get a MSD Cap & Rotor kit for it. You can install the reman one and keep the original as a spare or just do C&R on current one if that is all it needs and return the reman if you want

whatever you do, use blue loc-tite on the rotor screws

dialectic grease should be used on plug/opti wire boots. same with Opti 4 pin connector & coil wire

 

Yes I picked up some red locktite and I have a big tube of grease. I planned on trying to keep the old one if optical sensor isn't ruined. I'll be sure to post results once I get it in again

 

New opti installed and issues solved. Problems were loss of power, miss, and random backfire. Note, the car would start fine and rev fine in neutral. It would pull to shift point at WOT(however the lack of power was obvious). 14mpg economy. Problem did get a little worse as engine got hot. one bank was dumping fuel and the other was cutting fuel both in absurd amounts. I.E. blm bank 1 at 116 and blm bank 2 at 140.
The problem was the previous owner had the heads off. The waterpump gaskets and seals and all were new and the exact same felpro kit i had. The timing cover had also been off(the bolts on that were also not tight). Upon removing the old optispark The two small O-rings on the drive pin were gone, I am not sure if previous owner botched the re-install or they failed with age. I dug around with a pick and I couldn't find either one. Upon removal of distributor cap the points were corroded and one showing obvious signs of arcing. The rotor underneath was burnt and the plastic was burnt black and brown in a lot of places. Upon removal of the rotor and the shield underneath to reveal the sensor It was obvious a seal had let go. The entire sensor housing and bottom of distributor was full of oil. I am not sure if it had to do with the two o-rings being gone, the timing cover not being torqued, or a combination of the two(I also will not run synthetic anymore as well just because of its knack for finding tired seals.) The oil in the distributor in sense "blinded" the sensor and I believe that is why it did not throw a code as I think the sensor still would function. Note, I did NOT replace any seal due to them being dry and very new looking. I have full access to a lift at my shop and I have NO idea how people do this job on the ground off of stands.

 

oil inside the opti can come from leaks from wp drive seal, opti seal or intake manifold leak. If none of those showed signs of leaks they should be fine. The WP drive seal is the most common to leak

you want to have the 2 O rings on the opti spline shaft