seraphiem
New Member
I finally performed the upper 60k to my once neglected '93 ATX and discovered it was not really neglected as I once thought, except for the excessive dirt and grime.
The valve lash of all intake and exhaust (except 1) was within specs and most were right on the nominal value. Only one intake valve was widly out of spec, gap measured as 0.406 mm and I could only get it to within the top end of the range with the shims I had. The shims were all great and had mirror finishes.
The entire process took about 14 hours. Why so long? One valve cover bolt head was already stripped out before I touched it, and I snapped the corner valve cover bolt next to the cam chain. Luckily that particular bolt went into a threaded side-lobe instead of inside the head itself!
Now my problem....the rather strange idle problems that cropped up after the upper 60k. The car currently runs great and pulls better then I ever remember it. The seat of my pants says more power especially torque just off idle sprang up after the work. So I'm a little confused with this problem.
The car currently idles fine for about the first 60 seconds of when I start up the car. Right below 1k and very smooth. After that first minute the car drops down to what seems like 500 rpm and shakes so much it acts like its running on 5 cylinders. Very scary. If I apply any amount of throttle the car will smooth itself out immediately for another 60 seconds or so and then revert back to the rough and very low idle. Very frustrating.
To make things a little more fun, if I apply any amount of throttle to the engine when it is idling smoothly, it will stick. IE, if I rev the car to 2k, the idle will stick to 2k indefinately, until I apply a load to the engine such as putting on the A/C or engaging 'D'. If I rev it to above 2k, it will drop and then stick to 2k. For example, I rev it to 3k it will rev down to 2k and then stick there. Putting the car into 'N' will also cause the engine to idle at about 2k by itself with no interaction from me.
Frustrated I reset the computer and performed the idle set procedure twice. Checked all vaccum lines and looked for possible leaks in the intake. All seem good.
Any ideas on this weird idle problem?
Here's a little side note causing me to be a little paranoid. Just after I finished the upper 60k I fired up the engine and took it out for a quick spin. I took it for about a 7 - 8 minute ride a total trip distance of about 1.3 miles. Basically I drove it for almost a mile and discovered I was leaking coolant (no hood on and I could smell/see it burning off) and my temp gauge was rather high, IE the 'O' in NORMAL. Pulled over and let it idle for a few minutes and the temp stabilized. Started the remaining 2 minute and 1/4 mile home drive with the temp as it should be about 'A'.
But it quickly sprang up to the 'N' (like in seconds) and I had coolant all over my windshield. I got the car home and discovered I missed one coolant line on the end of the TB. And a lot more scary to me, I spewed out ALL (or most of it) of my coolant threw that line. The temp gauge never went above 'N' but I'm worried that the gauge doesn't work properly when there is nothing but air in the coolant system.
So is it possible to damage this engine by overheating it for only a 2 - 3 minute period? Did I even overheat it? It never went above the 'N' but then again it had little to no coolant in it. This rough idle scares me into thinking I blew the head-gasket on it.
Changed the oil and discovered no coolant in it, and vice versa. No bubbles in the coolant (when looking into the rad) when I rev the engine, and no white smoke coming out of the exhaust. Car seems to be running in the normal 'A' to 'M' range of temperatures. No compression test yet, may do that if I get paranoid enough.
Again any ideas on this idle? Sorry for the long post, just clueless at this point and hoping my little mishap didn't **** or fatally injure my toy.
Thanks for All the Help
Edit: All supporting sensors, O2, ECT, ACT, and TPS are only a few months or 3k miles old. The MAF has also been cleaned around the same time period.
The valve lash of all intake and exhaust (except 1) was within specs and most were right on the nominal value. Only one intake valve was widly out of spec, gap measured as 0.406 mm and I could only get it to within the top end of the range with the shims I had. The shims were all great and had mirror finishes.
The entire process took about 14 hours. Why so long? One valve cover bolt head was already stripped out before I touched it, and I snapped the corner valve cover bolt next to the cam chain. Luckily that particular bolt went into a threaded side-lobe instead of inside the head itself!
Now my problem....the rather strange idle problems that cropped up after the upper 60k. The car currently runs great and pulls better then I ever remember it. The seat of my pants says more power especially torque just off idle sprang up after the work. So I'm a little confused with this problem.
The car currently idles fine for about the first 60 seconds of when I start up the car. Right below 1k and very smooth. After that first minute the car drops down to what seems like 500 rpm and shakes so much it acts like its running on 5 cylinders. Very scary. If I apply any amount of throttle the car will smooth itself out immediately for another 60 seconds or so and then revert back to the rough and very low idle. Very frustrating.
To make things a little more fun, if I apply any amount of throttle to the engine when it is idling smoothly, it will stick. IE, if I rev the car to 2k, the idle will stick to 2k indefinately, until I apply a load to the engine such as putting on the A/C or engaging 'D'. If I rev it to above 2k, it will drop and then stick to 2k. For example, I rev it to 3k it will rev down to 2k and then stick there. Putting the car into 'N' will also cause the engine to idle at about 2k by itself with no interaction from me.
Frustrated I reset the computer and performed the idle set procedure twice. Checked all vaccum lines and looked for possible leaks in the intake. All seem good.
Any ideas on this weird idle problem?
Here's a little side note causing me to be a little paranoid. Just after I finished the upper 60k I fired up the engine and took it out for a quick spin. I took it for about a 7 - 8 minute ride a total trip distance of about 1.3 miles. Basically I drove it for almost a mile and discovered I was leaking coolant (no hood on and I could smell/see it burning off) and my temp gauge was rather high, IE the 'O' in NORMAL. Pulled over and let it idle for a few minutes and the temp stabilized. Started the remaining 2 minute and 1/4 mile home drive with the temp as it should be about 'A'.
But it quickly sprang up to the 'N' (like in seconds) and I had coolant all over my windshield. I got the car home and discovered I missed one coolant line on the end of the TB. And a lot more scary to me, I spewed out ALL (or most of it) of my coolant threw that line. The temp gauge never went above 'N' but I'm worried that the gauge doesn't work properly when there is nothing but air in the coolant system.
So is it possible to damage this engine by overheating it for only a 2 - 3 minute period? Did I even overheat it? It never went above the 'N' but then again it had little to no coolant in it. This rough idle scares me into thinking I blew the head-gasket on it.
Changed the oil and discovered no coolant in it, and vice versa. No bubbles in the coolant (when looking into the rad) when I rev the engine, and no white smoke coming out of the exhaust. Car seems to be running in the normal 'A' to 'M' range of temperatures. No compression test yet, may do that if I get paranoid enough.
Again any ideas on this idle? Sorry for the long post, just clueless at this point and hoping my little mishap didn't **** or fatally injure my toy.
Thanks for All the Help
Edit: All supporting sensors, O2, ECT, ACT, and TPS are only a few months or 3k miles old. The MAF has also been cleaned around the same time period.
