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Bought the car in June replaced the opti a few weeks after buying it, PO said it was ebay and I was getting a hesitation. After loctiting the screw and running the car it all seemed fine for a few weeks, I noticed a few hiccups about two months later but got worried when it got real bad after driving for an hour and a half in 6th gear mostly.
Ordered a new coil since I figured the last one was kicking the bucket, nothing changed, bought an ICM and put the paste on it with no luck, unplugged the EGR and capped the hose with no luck, tried unplugging the MAF and it ran worse than before. over the past week it's gone from a rare 6th gear thing to just about any gear at low RPM when at OT, to now where it even does it at idle.
Should I try o2 sensors next? I'm dreading that passenger sensor, could I not have put enough blue loctite on? possibly the opti going bad already?
-video is pending upload, link will be provided when it's up
You need to get an OBD1 ALDL cable and datalog it. Scan9495 is free. Gotta check to see what the sensors are doing.
Also, did you replace the opti harness with the new opti?
In the other thread you stated the tach was fluctuating, I assumed you meant the engine wasn't. Had I thought the engine was fluctuating too I would've leaned away from the coil and ICM.
Does having the AC on or off change the fluctuating idle?
You need to get an OBD1 ALDL cable and datalog it. Scan9495 is free. Gotta check to see what the sensors are doing.
Also, did you replace the opti harness with the new opti?
In the other thread you stated the tach was fluctuating, I assumed you meant the engine wasn't. Had I thought the engine was fluctuating too I would've leaned away from the coil and ICM.
Does having the AC on or off change the fluctuating idle?
I ordered the ALDL cable, I was reading up about it last night. The msd opti eliminates the harness I believe you're talking about. The opti I got plugs into the engine harness way up by the intake manifold, I don't work till Monday so I'd like to have it done by then could low coolant be causing the issue?
I'm not sure if the coolant is low but when I did the opti and changed the coolant I put dexcool in like an idiot so a week later I drained that crap and got the green stuff that was in it previously but whenever I tried to get air bubbles out I would fill the rad the thermostat would open and lower the level but it got to a certain point to where the coolant would just boil out of the cap.
The only way I could make it stop was by turning the engine off then the level would drop a bit into the rad but once the car was started it would boil again. I eventually just put the cap on and let it figure itself out, it did get up to about 210 every now and then if I wasn't moving but it rarely got that hot.
I have no idea if that could be related to my problem or not I'll check the coolant level and depending on how bored I am I may try to take off the passenger side o2 and replace both, I'd hate to wait around till that cord gets here.
Final thought should I change the fuel filter? I have no idea when it was done it doesn't look like the outside of it is overly dirty but I did run the tank down to about 1/2 a gal trying to get 300 miles on a tank is that bad mpg?
I ordered the ALDL cable, I was reading up about it last night. The msd opti eliminates the harness I believe you're talking about. The opti I got plugs into the engine harness way up by the intake manifold, I don't work till Monday so I'd like to have it done by then could low coolant be causing the issue?
I'm not sure if the coolant is low but when I did the opti and changed the coolant I put dexcool in like an idiot so a week later I drained that crap and got the green stuff that was in it previously but whenever I tried to get air bubbles out I would fill the rad the thermostat would open and lower the level but it got to a certain point to where the coolant would just boil out of the cap.
The only way I could make it stop was by turning the engine off then the level would drop a bit into the rad but once the car was started it would boil again. I eventually just put the cap on and let it figure itself out, it did get up to about 210 every now and then if I wasn't moving but it rarely got that hot.
I have no idea if that could be related to my problem or not I'll check the coolant level and depending on how bored I am I may try to take off the passenger side o2 and replace both, I'd hate to wait around till that cord gets here.
Final thought should I change the fuel filter? I have no idea when it was done it doesn't look like the outside of it is overly dirty but I did run the tank down to about 1/2 a gal trying to get 300 miles on a tank is that bad mpg?
No, the MSD definitely comes with and uses a harness, the harness that connects the opti to the engine wiring harness. You might have to take it apart and see if the a screw(s) backed out of the rotor, MSD should replace it if it's under warranty if it is the opti that went bad....but I would check for codes first. Hopefully the opti didn't get wet changing coolant...they don't like water
I had similar misfire symptoms in my LS1 car when I had a spark plug with broken porcelain insulation however...
No, the MSD definitely comes with and uses a harness, the harness that connects the opti to the engine wiring harness. You might have to take it apart and see if the a screw(s) backed out of the rotor, MSD should replace it if it's under warranty if it is the opti that went bad....but I would check for codes first. Hopefully the opti didn't get wet changing coolant...they don't like water
I had similar misfire symptoms in my LS1 car when I had a spark plug with broken porcelain insulation however...
The opti uses a harness correct but the old opti cord is like 3 inches that goes to a plug that is like a foot and a half that plugs into that harness the new opti has like a 2 foot cord that runs straight from the opti to the harness.
I was very careful to keep water away from the opti, that's why i didn't use the bleeder valve but kept the cap undone.
coolant level was full as I just checked, I read something about pressing the EGR diaphragm while it's running so I did that and when i pressed on it the car bogged down and releasing it returned it to normal so I'm guessing that's fine.
I'm going to try and find where I can plug a gauge into the intake manifold to check vacuum next.
Checking the Intake vacuum it seemed to hold right around 20-19 at idle and I noticed a hissing sound near the alternator, almost sounded like it could've been the alternator or the fan probably why i didn't notice it before. Further looking I found this hose that connects on the passenger side of the intake second one down. What is it for and should my local auto parts store have it?
The evap leak was not my problem, I'm about to pull the throttle body to clean the IACV any tips? I'll probably have to use permatex to make a gasket till I order one.
I'm thinking it's the TPS I was checking out the bolt locations for the IAC and unplugged the TPS, then when I went to drive to Advance auto (18 miles away) the whole way there besides the last mile it was perfect, got the gasket and most of the way home it was bad at one point in 2nd gear around 2100rpm i had my foot on the gas a little but then the car started to pull hard and spin the tires till I let off.
After that happened I was a bit furious and beat the car for a good bit running through 2-4th a few times but once I relaxed a bit there wasn't anymore jumping of the car or tach jumps.
Engine off, open both bleed screws, fill radiator until only coolant comes out of the bleeders. Close the bleeders, start engine and fill until full with engine at operating temps. Turn off engine and let cool completely, then fill radiator again.
If you are still getting bubbles after that you have another problem.
Engine off, open both bleed screws, fill radiator until only coolant comes out of the bleeders. Close the bleeders, start engine and fill until full with engine at operating temps. Turn off engine and let cool completely, then fill radiator again.
If you are still getting bubbles after that you have another problem.
He'll have all kinds of problems if he fills it that way. You can't fill the radiator up until it hits the heater hose bleed screw. It sits higher than the coolant level in the radiator. You must close the radiator after it has been bled from the t-stat and let the system build pressure before air can be purged from the heater hose bleed screw.
He'll have all kinds of problems if he fills it that way. You can't fill the radiator up until it hits the heater hose bleed screw. It sits higher than the coolant level in the radiator. You must close the radiator after it has been bled from the t-stat and let the system build pressure before air can be purged from the heater hose bleed screw.
Aaaaaahhhhhh after reading that it kind of clicked and made sense to me, I'll try to purge it from the heater hose bleed screw tomorrow. I only ever topped off in the radiator these cars are very specific, well worth it though great bang for the buck cars just very specific.
He'll have all kinds of problems if he fills it that way. You can't fill the radiator up until it hits the heater hose bleed screw. It sits higher than the coolant level in the radiator. You must close the radiator after it has been bled from the t-stat and let the system build pressure before air can be purged from the heater hose bleed screw.
That's how I do it. I push the heater hose down so it's below the radiator neck when I bleed it.......
Opening the bleeder screw with the system under pressure allows for expansion. That can put air in the system.
09-30-2015, 04:24 PM
Lt1 misfire help it's getting worse (((VIDEO))) 
