Branching this out of RR thread to put focus on some new problems, and what's been done so far. I'm just placing all of this into a tech thread so I can keep my primary focus on troubleshooting here instead of there.
So, '87 had a pooched valve on cylinder 1 on the factory E6 heads. Put some HO stuff on in place of factory stuff. Now there's driveability concerns, which I'll explain further down the post.
The engine received E7 heads, and a HO type upper intake with bored spacer and HO throttle body. All necessary mods to the upper intake were done to make it right for Panther use, however I had to swap over my TPS from the old TB to the new one. When the lower intake was installed, three of us lined it up and dropped it into place. All the bolts dropped straight in to their respective homes with no adjustment necessary, so I believe it is centered correctly since we opted not to use the studs for alignment (despite the fact I wanted to). It has been torqued and re-torqued. All the rocker arms were torqued at 25 ft-lbs.
When the engine was started for the first time, we did not run it long as we tested it without front accessories installed. It ran for about 45 seconds total. Timing was set at 10° BTDC during this time. It appeared to be running smoothly.
The second time the engine was fired, the front accessories were re-installed. The engine made a knocking noise from both sides during the first 30 seconds to a minute of running, however the noise stopped after the temperature gauge started coming up and coolant was reintroduced to the block. The idle seemed a bit high, but did come down to a certain degree, however idle did not seem as smooth (however still smoother than when it ran on seven cylinders). When the engine was revved, there was a slight hesitation with initial throttle tip in. In park, the engine could be revved up. A pop (or possible backfire) could be heard when letting off the accelerator on the driver's side after revving it. Some of the roughness was alleviated when I pushed down on some of the spark plug wire connectors at the distributor. It was noted when putting the wires back on, they didn't all have a signature "click" when installed on the plugs.
On the test drive, you could accelerate somewhat normal with light accelerator pressure, but floored it wouldn't do jack, was slow to pick up and would pop every so often. Lacked power bad.
While sitting in the driveway idling, it smelled a bit richer than normal, but my nose isn't that great and the exhaust is un-catted, which doesn't help at all. I'm not sure if it's running too rich at idle and too lean at WOT. One of the guys helping me said he could hear a hissing from the passenger side of the engine bay, but I've always heard a slight hiss. The only vacuum lines on the passenger side are the MAP sensor, the main vacuum feed from the vacuum tree, the small vacuum feed that goes to the EGR solenoid, and the EGR line. This car still has the hard plastic vacuum lines, but I've cracked one before, however I doubt that small of a leak would cause the bad of a driveability concern.
So I do need to see if any codes are stored. I wasn't able to pull anything at the time since I lacked anything to pull codes with.
After scouring the internet, trying to get any good info for symptoms, I got some pointers, but of course codes will be helpful if there's other issues.
Current plan:
-Check codes
-Replace wires; Questionable connections won't help
-Possibly try adjusting rocker arms; Interwebz says over-tightened doesn't make the engine run better
-Check for vacuum leaks
-Adjust TPS to get it into acceptable voltage range; current setting is unknown and may be out of range
Of course, the GMN gurus' input is always very welcome since I'd love to get this thing running right. Also, forgive me for the long posts, I'm just trying to put my thoughts in a single spot and this has got me stressed out trying to get it right. I'll try and get out to the wagon next week (working rest of this week) and start trying to do some diagnosing so I can give y'all some more information.
So, '87 had a pooched valve on cylinder 1 on the factory E6 heads. Put some HO stuff on in place of factory stuff. Now there's driveability concerns, which I'll explain further down the post.
The engine received E7 heads, and a HO type upper intake with bored spacer and HO throttle body. All necessary mods to the upper intake were done to make it right for Panther use, however I had to swap over my TPS from the old TB to the new one. When the lower intake was installed, three of us lined it up and dropped it into place. All the bolts dropped straight in to their respective homes with no adjustment necessary, so I believe it is centered correctly since we opted not to use the studs for alignment (despite the fact I wanted to). It has been torqued and re-torqued. All the rocker arms were torqued at 25 ft-lbs.
When the engine was started for the first time, we did not run it long as we tested it without front accessories installed. It ran for about 45 seconds total. Timing was set at 10° BTDC during this time. It appeared to be running smoothly.
The second time the engine was fired, the front accessories were re-installed. The engine made a knocking noise from both sides during the first 30 seconds to a minute of running, however the noise stopped after the temperature gauge started coming up and coolant was reintroduced to the block. The idle seemed a bit high, but did come down to a certain degree, however idle did not seem as smooth (however still smoother than when it ran on seven cylinders). When the engine was revved, there was a slight hesitation with initial throttle tip in. In park, the engine could be revved up. A pop (or possible backfire) could be heard when letting off the accelerator on the driver's side after revving it. Some of the roughness was alleviated when I pushed down on some of the spark plug wire connectors at the distributor. It was noted when putting the wires back on, they didn't all have a signature "click" when installed on the plugs.
On the test drive, you could accelerate somewhat normal with light accelerator pressure, but floored it wouldn't do jack, was slow to pick up and would pop every so often. Lacked power bad.
While sitting in the driveway idling, it smelled a bit richer than normal, but my nose isn't that great and the exhaust is un-catted, which doesn't help at all. I'm not sure if it's running too rich at idle and too lean at WOT. One of the guys helping me said he could hear a hissing from the passenger side of the engine bay, but I've always heard a slight hiss. The only vacuum lines on the passenger side are the MAP sensor, the main vacuum feed from the vacuum tree, the small vacuum feed that goes to the EGR solenoid, and the EGR line. This car still has the hard plastic vacuum lines, but I've cracked one before, however I doubt that small of a leak would cause the bad of a driveability concern.
So I do need to see if any codes are stored. I wasn't able to pull anything at the time since I lacked anything to pull codes with.
After scouring the internet, trying to get any good info for symptoms, I got some pointers, but of course codes will be helpful if there's other issues.
Current plan:
-Check codes
-Replace wires; Questionable connections won't help
-Possibly try adjusting rocker arms; Interwebz says over-tightened doesn't make the engine run better
-Check for vacuum leaks
-Adjust TPS to get it into acceptable voltage range; current setting is unknown and may be out of range
Of course, the GMN gurus' input is always very welcome since I'd love to get this thing running right. Also, forgive me for the long posts, I'm just trying to put my thoughts in a single spot and this has got me stressed out trying to get it right. I'll try and get out to the wagon next week (working rest of this week) and start trying to do some diagnosing so I can give y'all some more information.
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