Oh joy, opti?
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Oh joy, opti? Rewind to a couple days ago. I found a small puddle of coolant under my car dripping from right under the crank pulley. Immediatly i figure the water pump was done and needs to be changed. Past couple days, nothing on the ground. But you can see the coolant hanging on the bottom of the block. So i know there is a slow leak.
Fastforward to today, i got my pcm4less tune and put it in and took the car for a spin (throws a P1657 code for some reason but thats a different story) and the car was spuddering in higher rpm ranges with my floot through the floor boards. If i take it up to 5000rpm in first or second gear, the slight stumbling occurs at around 3800-4000 to 5500 (when ever it wants to inbetween, sometimes not at all) So i change back to the stock pcm, same issue.
Other then this issue which JUST started tonight, was fine earlier. The car runs damn good, and pulls strong.
Work recently done
Walbro255 pump with wiring kit, plugs, wires, fuel filter, long tubes, ory, egr/air/cat delete. Car basically had a full tune up 3 weeks ago.
Car smells like its running rich, i have 2 new o2's waiting to go in.
I want to make sure all the excess ceramic is burnned off the headers first.
Am i right to think the opti is about to kick the bucket because of the coolant leak from the waterpump?
Also could fouled o2's be causing this high rpm stumble?
I imagine ill end up doing a new optio and water pump with gaskets anyways, but would rather be sure before i go and dump $800 heh.
Thanks in advance
P.S Someone at my shop mentioned maybe a broken valve spring? Im sort of doubting that tho as the stumbling seems intermittent. Thanks again.
Fastforward to today, i got my pcm4less tune and put it in and took the car for a spin (throws a P1657 code for some reason but thats a different story) and the car was spuddering in higher rpm ranges with my floot through the floor boards. If i take it up to 5000rpm in first or second gear, the slight stumbling occurs at around 3800-4000 to 5500 (when ever it wants to inbetween, sometimes not at all) So i change back to the stock pcm, same issue.
Other then this issue which JUST started tonight, was fine earlier. The car runs damn good, and pulls strong.
Work recently done
Walbro255 pump with wiring kit, plugs, wires, fuel filter, long tubes, ory, egr/air/cat delete. Car basically had a full tune up 3 weeks ago.
Car smells like its running rich, i have 2 new o2's waiting to go in.
I want to make sure all the excess ceramic is burnned off the headers first.
Am i right to think the opti is about to kick the bucket because of the coolant leak from the waterpump?
Also could fouled o2's be causing this high rpm stumble?
I imagine ill end up doing a new optio and water pump with gaskets anyways, but would rather be sure before i go and dump $800 heh.
Thanks in advance
P.S Someone at my shop mentioned maybe a broken valve spring? Im sort of doubting that tho as the stumbling seems intermittent. Thanks again.
Last edited by 97lt1camaro; Aug 7, 2008 at 01:04 AM.
You need to start doing a diagnosis in a logical order. In other words, what happened first....
You had a coolant leak develop, which is know for messing up the opti. HOWEVER, you continued forward, and installed the reprogrammed tune in the car, and naturally, wanted to see how good it'll go...........
Personally, although it's a PITA, I think you should have gotten a new waterpump first, since it's telling you it's wounded, and while you're in there, replace the cap and rotor of the opti, and also give the inside of the opti a good cleaning. The opti not rocket science, it's just a cast aluminum housing with a rotating optical wheel, an optical sensor, and the distributor rotor. The only thing you need to be careful about is not bending the optical wheel, and making sure you put it back together EXACTLY the way it came apart. You'll also need a couple of Torx bits, #4s, both male and female for the disassembly. IMHO, replacing the entire opti as a unit is a waste of money. A cap and rotor can be purchased for around $160, and it takes maybe 20-30 minutes to do the swap over and housing clean out. (I've done it twice on my Z-28)
Once you get the ignition back in top shape, you SHOULD be good to go. Although it's possible, I highly doubt that you suddenly developed valve spring or ignition wire issues, given the fact that the water pump seems to have started this chain of events.
One other thing...Make sure to install a new oil seal in the front cover of the engine, where the opti feeds through. If you don't, you're asking for an oil leak...
You had a coolant leak develop, which is know for messing up the opti. HOWEVER, you continued forward, and installed the reprogrammed tune in the car, and naturally, wanted to see how good it'll go...........
Personally, although it's a PITA, I think you should have gotten a new waterpump first, since it's telling you it's wounded, and while you're in there, replace the cap and rotor of the opti, and also give the inside of the opti a good cleaning. The opti not rocket science, it's just a cast aluminum housing with a rotating optical wheel, an optical sensor, and the distributor rotor. The only thing you need to be careful about is not bending the optical wheel, and making sure you put it back together EXACTLY the way it came apart. You'll also need a couple of Torx bits, #4s, both male and female for the disassembly. IMHO, replacing the entire opti as a unit is a waste of money. A cap and rotor can be purchased for around $160, and it takes maybe 20-30 minutes to do the swap over and housing clean out. (I've done it twice on my Z-28)
Once you get the ignition back in top shape, you SHOULD be good to go. Although it's possible, I highly doubt that you suddenly developed valve spring or ignition wire issues, given the fact that the water pump seems to have started this chain of events.
One other thing...Make sure to install a new oil seal in the front cover of the engine, where the opti feeds through. If you don't, you're asking for an oil leak...
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Motor was driving fine and pulling hard since the header install.
About 3-4 days ago i found a small puddle of coolant under the car dripping from the bottom of the crank area, behind the pully. I wiped the coolant off the motor, as far as i could see, and left it at that keeping in mind a water pump and opti might be in the near future.
After the day i found coolant leaking, i kept an eye on it. The car hasnt dropped a single drop of anything in the past 3 days. However, as of yesterday, AFTER the new pcm install, i noticed the stumbling/missing when i was romping on it. It wasnt pulling right, it wasnt slow by any means, but you could definitly feel that it was stumbling/missing at certain points in the higher rpm range.
I figured at this point the tune might of been bad perhaps or something. So i put back in the stock pcm, go out for a run and the same problem occurs. Missing/stumbling at higher rpms.
No codes or engine lights or anything. Just sounds like it "puffs" almost when it misses/stumbles.
Today i drove it to work, it was fine on the first hard WOT runs. Then towards the end of my drive, i got on er again and yet again the problem reoccured.
Same thing at lunch. Take it out, let it warm up a bit, first 4-5 WOT runs are perfect and pull hard, then the problem occurs.
Same thing happened on the way home from work today, cept it took a bit longer for the problem to re occur.
The water pump has NOT leaked a drop since the first inital puddle.
About 3-4 days ago i found a small puddle of coolant under the car dripping from the bottom of the crank area, behind the pully. I wiped the coolant off the motor, as far as i could see, and left it at that keeping in mind a water pump and opti might be in the near future.
After the day i found coolant leaking, i kept an eye on it. The car hasnt dropped a single drop of anything in the past 3 days. However, as of yesterday, AFTER the new pcm install, i noticed the stumbling/missing when i was romping on it. It wasnt pulling right, it wasnt slow by any means, but you could definitly feel that it was stumbling/missing at certain points in the higher rpm range.
I figured at this point the tune might of been bad perhaps or something. So i put back in the stock pcm, go out for a run and the same problem occurs. Missing/stumbling at higher rpms.
No codes or engine lights or anything. Just sounds like it "puffs" almost when it misses/stumbles.
Today i drove it to work, it was fine on the first hard WOT runs. Then towards the end of my drive, i got on er again and yet again the problem reoccured.
Same thing at lunch. Take it out, let it warm up a bit, first 4-5 WOT runs are perfect and pull hard, then the problem occurs.
Same thing happened on the way home from work today, cept it took a bit longer for the problem to re occur.
The water pump has NOT leaked a drop since the first inital puddle.
You may want to check into your ignition plugs since your headers are still relatively "new" in there, make sure your plugs arent arching or touching the headers. Its a common miss with the LT's....
-justin
-justin
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Im actually starting to think it is the wires.
I took it out for a spin after i checked under the valve covers.
Running amazing for about 20 minutes. Then started doing it again, and then seemed to stop.
It almost feels like if i "roll" into the throttle instead of just punching it(which causes the car to lurch forward) it will run smooth. Otherwise it seems to spudder. Im not positive on this, but once i get the car in the air ill check all the plug wires and tie them off a bit better.
I took it out for a spin after i checked under the valve covers.
Running amazing for about 20 minutes. Then started doing it again, and then seemed to stop.
It almost feels like if i "roll" into the throttle instead of just punching it(which causes the car to lurch forward) it will run smooth. Otherwise it seems to spudder. Im not positive on this, but once i get the car in the air ill check all the plug wires and tie them off a bit better.
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Also the old o2s are still in there (the fronts on the collectors) They have been in there for 3 tanks roughly. Smells like the car is running quite rich now, would i be good to change them out now, or should i let the headers go through a few more heat cycles to finish burning off the ceramic coating that would foul the o2s?
If you were going to change your O2s anyways, do it now as that could be causing your problem (If you think you smell a rich condition). It wouldent be unheard of to have the coating burn off a little and foul the O2s. The problem being intermittant like that could also mean its the O2s, as my truck did the same thing when the O2s were bad (ran great for 20 minutes, crap for 10, perfect for 20, crap for 10 ect...)
Keep an eye on that coolant leak though, that could still cause the problem or get worse on its own.
Keep an eye on that coolant leak though, that could still cause the problem or get worse on its own.
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Yea ill change em out tomorrow then.
Ive also been checking under the car/ on the block for coolant since i spotted it that one day 3-4days ago. Nothing has dripped down or even shown up on the block. So i have no idea whats going on that, but ill keep checking none the less.
Ive also been checking under the car/ on the block for coolant since i spotted it that one day 3-4days ago. Nothing has dripped down or even shown up on the block. So i have no idea whats going on that, but ill keep checking none the less.
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Verdad Gallardo If this stumble started RIGHT after you installed the LTs, then its very possible its the O2s (could have been bad to begin with, OR got dirty on the new install, OR coating/debris burning off the insides in the first miles fouling them).
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No i installed the headers,ory,plugs, wires, and fuel pump and deleted the egr/air/cat/rear o2s about 2 weeks ago
Car started acting up last night. Its a really light studder.. Just enough to feel it, and slow the car very little. But enough to be annoying lol
Car started acting up last night. Its a really light studder.. Just enough to feel it, and slow the car very little. But enough to be annoying lol
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Thanks, yea the car is in quite good shape still. Paint in spider cracked on the rear bumper beside the rear side lights, other then that a few rock chips on the hood and a minor nick on the door trim. 
Yea, i pay very close attention to my car when i drive it. Basically if i think i heard something or felt something, i worry about it till it drives me up the wall and i think there is a problem haha. In this case im right, but yea. Im paranoid lol.
Could the coil or icm have any contributing factors in this odd stumble/mis?
Yea, i pay very close attention to my car when i drive it. Basically if i think i heard something or felt something, i worry about it till it drives me up the wall and i think there is a problem haha. In this case im right, but yea. Im paranoid lol.
Could the coil or icm have any contributing factors in this odd stumble/mis?
Yes, a coil could cause a condition somewhat like that, although if it were a coil Id think it would be breaking up ALLLL the time or just straight up die as soon as the coil got hot (usually the heat that gets them).
Since they are easy to check, it could be a good idea to pull the coil/ICM and have them checked at a local parts store. Doesnt cost anything and it gives you piece of mind when diagnosing. And hell, while you have them out do the "ICM cooling mod" in which you put the bracket that holds the coil/ICM assembly on longer bolts that hold it away from the head (a couple inches) to keep both cooler and promote airflow.
Since they are easy to check, it could be a good idea to pull the coil/ICM and have them checked at a local parts store. Doesnt cost anything and it gives you piece of mind when diagnosing. And hell, while you have them out do the "ICM cooling mod" in which you put the bracket that holds the coil/ICM assembly on longer bolts that hold it away from the head (a couple inches) to keep both cooler and promote airflow.
"97", I think it's still possible that you may have gotten a bit of coolant in your opti, and while you have a "vented" cap (it is a '97, right?) you still have traces of coolant in the cap, possibly causing arcing.
I changed out the cap on my car a couple of weeks ago. The car has 70,000 miles on it, and this is the second time I've changed it, as I'm big on maintenance. This time around, the cap wasn't as "toasted" as the OE cap was, but I had some traces of engine oil in the distributor housing. One of the o-ring seals must have started to "seep" a little.
I changed out the cap on my car a couple of weeks ago. The car has 70,000 miles on it, and this is the second time I've changed it, as I'm big on maintenance. This time around, the cap wasn't as "toasted" as the OE cap was, but I had some traces of engine oil in the distributor housing. One of the o-ring seals must have started to "seep" a little.
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I wouldnt be surprised if this was the case. As said as soon as i seen that coolant leak i figured my opti was a goner. I was quite surprised to see the car drove fine for about 3 days before it started acting up. Also it would make sense if that were the case, cause over the past 2 days, the stumbling has decreased significantly. I think i may luck out and if the pump doesnt leak again,( i still have actually found out if it came from that weep hole, hopefully today i will), maybe it will just dry up and be good to go.
Has anyone ever tried putting electrical cleaner down the opti vent tube haha?
Has anyone ever tried putting electrical cleaner down the opti vent tube haha?
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Turns out when i changed the wires, the ******** gave me the wrong wires. Plug wires were all the same, ign coil wire was different. Different end on coil end. I thought nothing of it as i had never done LT1 wires before, boy do i feel dumb now 
lol.
My car decided it didnt want to start today at work. I check the coil wire, it falls apart in my hand with part of my ign coil. Turns out i melted the ******. Upon further inspection, turns out the wrong plug end was making it so it was having to jump about half a inch to get spark....FOR THE PAST 3 WEEKS!!
I install a new msd coil, $40 dollar as opposed to the stockers at napa for $ 70 hahaha, but cannot find just a coil wire for the life of me. They want me to buy a whole new set... **** that..
I look around, and then think, Maybe ill check my brothers wrecked jetta to see what his plug wires look like. So i go outside and look at the car, hrm, that ign coil wire looks awefully similar. Take it off and put it on my car, plugs in fine and snaps in nice and tight!. Car starts up immediatly, and now my high rpm mis/studder is gone. I also installed new o2's and my new tuned pcm. Yay!..
Anyways thats my story of me being a moron. enjoy
lol.My car decided it didnt want to start today at work. I check the coil wire, it falls apart in my hand with part of my ign coil. Turns out i melted the ******. Upon further inspection, turns out the wrong plug end was making it so it was having to jump about half a inch to get spark....FOR THE PAST 3 WEEKS!!
I install a new msd coil, $40 dollar as opposed to the stockers at napa for $ 70 hahaha, but cannot find just a coil wire for the life of me. They want me to buy a whole new set... **** that..
I look around, and then think, Maybe ill check my brothers wrecked jetta to see what his plug wires look like. So i go outside and look at the car, hrm, that ign coil wire looks awefully similar. Take it off and put it on my car, plugs in fine and snaps in nice and tight!. Car starts up immediatly, and now my high rpm mis/studder is gone. I also installed new o2's and my new tuned pcm. Yay!..
Anyways thats my story of me being a moron. enjoy
Thats no moron move, you couldent even see what was under that boot (nothing).
In fact I give you credit for even looking there when it dident start, but congrats on getting the beast going again!
In fact I give you credit for even looking there when it dident start, but congrats on getting the beast going again!
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No but the reason it basically exploded in the first place is because i put the improper wire end on it. Which i mean i had no way of knowing, but i should of noticed something when i installed it haha.
Either way, she pulls good now. Ill be on the rolling road this friday to see what kind of numbers im putting down. Im excited ! First dyno run ever haha.
