BALLSS

OP

we have all been there on wtf is wrong with this LT1 on so many levels working on it which is frustrating. Walk away, have a beer and get back at it later. life is to fing short to let this kind of crap take over your mind

so....you had a crossed wire, dropped a plug and possibly cracked it. This shiat happens. You just need to be methodical on how you do wires & plugs. Yeah they are a bitch on these motors, especially f-bodys. I hope you ran the wires through all the stock looms & brackets. dropping starter for passenger side and working from underneath makes that side more doable. use dialectic grease on both wire boot ends

a misfire under load often is a plug arc. you need to look at night VERY carefully. If you can't se every part of the plug boot you will miss the arc. look from under the car, whatever you have to do to see each one. If your heat shield boots are on plug ends the arc can be between that shield and boot making it VERY hard to see so just dump those heat shields if you have them on

while you can install the pin opti wrong it takes effort as it will not sit flush with block by just holding it on with your hand. Using the 3 bolts to draw it in will f it up. Not sure it will even run if somehow the cam pin is on the other 2 slots

your "new" AC Delco opti is a reman unless somehow you found a NOS one somewhere. Does that mean it is 100% good, no but it should be

I would keep your old opti if the rear bearing is still good and just get a MSD cap & rotor for it and keep it as a known good spare.

hang in there, it is all fixable

demonsmokr

It's hard remaining methodical for the #8 plug. I dropped the whole socket, not just the plug. It only hit the tip and needed to be gapped. It never came out of the socket, it was the only one i dropped. That was at the end of superbowl night, around 12 am. I had more trouble getting it back in than out.

So, i had the p1371 or whatever. Replaced the harness, as it was very brittle. It fired up, but still running rough. No misfire codes, but still seems off.

It starts very rough, i keep thinking is the starter, but my buddy disagrees. He's an actual mechanic, I'm a backyard or shade tree guy. So, I'm kinda agreeing with him, but not ruling the starter out as it looks to be OE.

After about 4 or 5 rough starts, holding the throttle slightly open to keep it running, we got a crank shaft position sensor code. I forgot to note the number. But it cleared, and wouldn't come back right away. Only after a few bad starts.

I had to come into work, and i may have to take it home. His boss doesn't like me working on my car there, understandable. So, i offered an hour of pay for the time. If we can't get it tomorrow morning, i gotta bring it home

I hate working off the ground with these cars. Had it on the lift, and removed everything and reinstalled in little over an hour. Having the right tools and a lift takes so much anger away, i could just clearly think. It's amazing. But we're both stumped.

He has a new crank shaft sensor on his truck, which i think is the same for the LT1, his is a 98 Chevy 350 vortec. I think they're the same, he'll let me know.

It pisses,me off because it ran ok before, but was leaking, and would miss at higher rpms when i got on it.

There's no backfires while is running, but sometimes when it starts. Sometimes seems is sparking on an empty cylinder, we didn't check actual pressure, but we're getting fuel from the pump when turned on.

I'm lost right now. Gonna research tonight, try again in the morning.

demonsmokr

Second opti didn't die, but harness was jacked and giving me the code. I replaced just the harness, not the unit.

I replaced that, code has not come back, but we're getting a crankshaft code. Would this cause rough starts and a symptom similar to misfiring? I'm not getting any misfire codes, but it doesn't sound right.

SS RRR

iTrader: (2)

I am not sure if you still have backfiring or not, but if you do, in your case it is highly likely a timing issue which means the opti or plug wires.

demonsmokr

No back firing except when it stalls. When it runs, it's running rough, but not backfiring. We've quadruple checked firing order from opti to plugs, we're checking again while waiting on the crank sensor. They just sent the wrong one, LS1, not LT1.

What sucks is his boss is not happy my car is still here. Might have to take it home. However, we have verified everything is installed right, so i shouldn't have to get under it again. Hopefully.

Shownomercy

iTrader: (1)

Crank sensor is for misfire detection only, so I wouldn't bother worrying about that till you fix the misfire. Which is opti/plug/wire related.

demonsmokr

I can't see any external arcing. Not saying there is no arcing, if there is in not seeing it. We checked the #8 plug, the only one i dropped and it looks fine. Maybe I'll get another just in case.

Only other thing is the wires themselves? Maybe they're messed up and we don't see it.

In heading to O'Reilly to check out some custom length ones.

BALLSS

what brand of wires did you just put in?

demonsmokr

ACDELCO. OE set.

ahritchie

iTrader: (1)

Once you do the OTV conversion, you'll wonder why you ever fooled with stock plug wire routing. Especially if you ever get headers. Or maybe the AC delco optispark remanufacturing plant in Mexico or China might be having quality control issues lately.

Seems like MSD is the most patriotic optispark to run.

demonsmokr

O'Reilly didn't have any custom sets, just for old school stuff. Didn't even have replacement wires, they're special order.

I guess I'll have to order some online. But it doesn't seem like the wires are bad. Firing order is good, plugs are good, wires seem ok, it's almost like I've got a bad cylinder.

Replaced the crankshaft sensor, code came back. We're lost. He's going to try to get a compression test on the cylinders today if he can get to it.

I gotta go into work, so this project is going into day 5.

hrcslam

As much as replacing spark plugs sucks, I always do a compression check of all cylinders while they are out. It takes longer, but its a good health check to eliminate issues of you run into one.

Honestly though, with the issue arriving after what maintenance you did, I'd lean towards a bad opti out of the box. I've seen it before where a brand new opti is clocked wrong between the rotor and cam driven sprocket before.

You can check it if you have the old one. With the rotor installed, compare the rotor position with the drive unit on each opti, they should be the same. Sometimes they are off in alignment out of the box.

Also, you said the car was on a lift, that means you dropped the spark plug from pretty high. I'd replace it. Also, what spark plugs did you use?

chaney1974

I am curious why didn't you just pull the opti back off to make sure you had it in the right spot. phttp://shbox.com/1/opti_back.jpgin? check this picture out this shows the installation

chaney1974

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

demonsmokr

We did, we've done a full remove and install. I dropped the plug at the house when i was working off jack stands. Dropped maybe 2ft, wasn't a straight drop, hit the starter then fell, it stayed in the socket, the only thing that contacted the ground was the threaded portion.

Should i spring for the MSD complete unit? Does Mallory make one? We're lost.

I'm paying his lead tech a case of beer to determine the problem. My buddy is the manager/service advisor guy. He's like me, can work on carb motors with his eyes closed, can kinda work on ecm cars, but gets lost if the computer doesn't tell him anything. So we gotta give in and ask the smart guy.

I'm gonna wait to see what he thinks before i spend any more money.

BTC

Do you have a warranty on the opti you just put on it? If so, I would swap it for another. I would personally stick with AC Delco or Delphi over and MSD. Maybe you can get lucky and find a new one as opposed to a reman, but that may not be likely.

Have you confirmed fuel pressure and delivery?

demonsmokr

I ordered it from amazon. Can exchange it no problem, but gotta wait. They won't send anther without me sensing this one back first.

We have not confirmed fuel pressure and delivery. If there was a problem here, would it cause a timing issue and throw only the crank code?

That's the only code I'm getting. Got the opti harness code, but it hasn't come back after fixing the harness.

I'm at a loss. Right now, all i can do is wait until the morning to see what the tech says. If the news is bad, as in a bad cylinder or valves, I'm really at a loss.

Not sure what I'll do in that situation. My tax return will be enough for 1 of 3 options. Rebuild the LT1, find 5.3 and do the swap, or regress to a TPI motor and be weird. But all of those will put my car or if commission for a substantial amount of time. We only got the 2 cars, i work graveyard so the wife can't take me to and from work.

This is suspenseful.

hrcslam

The opti has a high and low resolution. The low resolution is crank position. If that doesn't match the crank position sensor, it should throw a code. If the rotor is not clocked correct to the drive unit (where it's pressed together) it'll cause issues. This has happened before, but usually not with Delphi or AC Delco units.

Also, what spark plugs did you install? And do you still have the old opti?

demonsmokr

NGK G-Power TR55 platinum.

I still have the old opti. It's at the house though. I took it apart to inspect it and broke 2 screws. Inside of cap is burnt pretty bad. Then the wheel thing fell out and hit the floor, i wasn't paying attention at that point as i was tired as hell.

What should i look for? Do i only need to focus on the rotor and sprocket on the back side? My original opti, i removed the rotor itself, but it only goes on 1 way. I could slap it back on and compare.

I got called in for an interview tomorrow. Just looming for a better job, what sucks is that's at 8am. I'll be pulling an all nighter tonight. But, that gives me now time at my buddy's shop before work tomorrow.

I'll play with the old opti tonight to keep me occupied. Get it back together, drill out the broken bolts, maybe replace the cap and rotor with the ones from the complete unit and see what happens.

BALLSS

not sure which screws you broke in/on the opti and if you did any damage to the wheel, etc. Given your description I would either stick with the "new" (rebuilt) ac delco. If you are throwing any low or high resolution opti codes than yeah replace/return that opti. if its a cc charge than just buy another if you are just "returning for refund" the one you just got

sometimes you can crack porcelain on plugs if socket gets a little wonky on hard to access ones on install. Plug arc can be hard to find. I chased one for months after replacing every other "ignition" part, including Opti, only to find by chance while under the car with engine running looking at something else I saw a "arc" from #6. Could in no way see it from up top. Swapped that plug wire out and all was good. No more stumble. So it really is worth checking especially from under the car plug/wire arc.