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I was out tuning my new combo in OLSD to get the VE dialed in today and when the converter locked up, it felt/sounded like it backfired. I was running it a bit rich ~ 12.8:1 while keeping it under 2.5k rpms to see how the VE table needed to be adjusted. So this was getting up to speed and when it locked up around 42 it did it. After that it started feeling like it was fluttering. It otherwise felt okay. I didn't want to push it much above 50mph (see the attached picture - notice that waviness - never seen that in any tune before).
I turned around and came home. I checked it out and it seemed ok. So then I fired it back up and it billowed white smoke (hadn't to that point). And it was not at idle. Only on startup and when giving it some gas under load.
I tuned the idle before I took it for a drive. It idled for about 30 mins total while I added coolant, tuned RAF, and tuned A/F and timing. So it got up to temp (220 due to air pocket in coolant).
It was an otherwise running car with a larger cam. I swapped the cam over the summer to a smaller one. Head did not come off. I have an oil leak from the back of the pan (had to drop the pan) that may be new (but hard to tell as I spilled oil under the car when I changed the oil) but it definitely was dropping oil in the driveway.
Any idea what it could be? Did it backfire and damage a water jacket? Why is it fluttering with constant TPS pressure? You can watch the speedo wobble. And you can feel it. And it's not cam surge. The new cam got rid of that...
This is with the bigger cam. Even in CL mode the MPH never fluttered like that?
What's causing that? I'm sure the white smoke and this are related. I triplechecked the pushrod length, but I'm running Johnson .058" total travel short lifters. When I did it before, the motor was out of the car and it was very easy to measure. This time I did it in the car, but still was careful to check. A few of the pushrods were different than others, but got pushrods that worked for them. Now I'm worried I'm hanging a valve open or something and getting flutter/blowby.
The other thing is, it doesn't do it when unlocked. It's smooth. But here is when it locked up... RPMs rose a lot too. TPS stayed around 11% that RPM ~ 1800 and 45mph and then it jumps to 2800 and then the issues began. I wasn't really paying attention as the car was shaking like the trans had been ripped lose and was rattling horribly. But it locked up fine after that. But then the white smoke came...
ANY ideas?
Last edited by JakeFusion; 10-07-2016 at 08:17 PM.
Going to go check it out to see if I broke a ring. I had it idling yesterday much richer than I expected... and I wonder if I washed the cylinder down in gas. Didn't have the O2 hooked up. Was watching the narrowbands. So I don't know if it was 10:1 or what. But it was just idling.
The MAP readings are very high for this size cam. Also plan to check for leaks around the FAST. It seems to work itself loose every few months.
Last edited by JakeFusion; 10-07-2016 at 10:06 PM.
You probably don't want to hear this but white smoke is typically steam. It would be worth looking at your plugs for evidence of either rich, oil, or water.
You probably don't want to hear this but white smoke is typically steam. It would be worth looking at your plugs for evidence of either rich, oil, or water.
I know. I hate pulling #7 tho and that's my concern.
I'm going to go mess with it in daylight this morning. See if the smoke is blue at all. It doesn't seem real thick - pretty wispy, so I don't think it's coolant. Doesn't have that sweet coolant smell either. So I'm thinking it's oil. Since the heads are still new, either I'm hanging a valve open with a pushrod that's too long or a ring has given up the ghost.
I know. I hate pulling #7 tho and that's my concern. I'm going to go mess with it in daylight this morning. See if the smoke is blue at all. It doesn't seem real thick - pretty wispy, so I don't think it's coolant. Doesn't have that sweet coolant smell either. So I'm thinking it's oil. Since the heads are still new, either I'm hanging a valve open with a pushrod that's too long or a ring has given up the ghost.
that's good if you're not smelling it. If you're lucky, oil might just be bypassing a rocker bolt. But I don't see how that would hurt the performance like that
its possible.... if you have been running the car at light load and at startup under no load white smoke can be a combination of moisture and oil(which is a common pcv ls issue and not of concern). this is more noticeable with the absence of catalytic convertors. idling around will produce internal steam that makes its way from crank to manifold and back into cylinders. tune a car at operating temperatures and if your tuning idle you dont want to spend more than a few minutes in your idle cells before you light cruise and come back to idle to stabilize cylinder temps.
when the convertor locks up the MAP reading may spike to a higher kpa than youd expect.. even at steady TPS. check to see what your timing and VE looks like in the high MAP areas
is there any particular reason why you dont want to tune in closed loop with o2 feedback? looks like this is a street car?
I start in OLSD to build the VE table then switch to CLSD to verify. Then I move to CLMAF since I do run it with a MAF - and MAF is the easiest to tune.
Turns out it was the number 7 intake rocker. Issue with the trunion and pushrod. Hopefully that clears it up... would account for oil and funky MAP readings... 75kpa with this cam is too low of a vacuum with the cam. It should read around 55. But it didn't drive like it had 75. So it was leaking air through the #7 intake and sucking in whatever. Wispy white smoke...
I'll see how it runs tomorrow. If there is an issue, I'll move to checking the health of #7...
that would explain it! I had some driveability and surging issues after tuning with the stock MAF even with everything appearing to be perfect. 232/234 111lsa with decent overlap so I ditched the MAF and have been loving the car since.
10-07-2016, 07:44 PM
My mph/rpm very unsteady with constant TPS? 
