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The cam has an "A" at the end, which I believe points to oem. I sure hope there's no bent valves in there, from my previous post on the vacuum gauge, the motor ran smooth up to 3,500rpm's. It's been parked in the garage for the last 9 months and all I have been doing is verifying operation of all it's FI, emissions, vacuum, electrical bugs, etc....basically giving her a once over. I was going to get to the valve adjustment tonight, first wanted to check the TDC reference marks.

Without pulling the head are there any indicators to determine if either one was shaved?

I was looking for that reference guide, thanks. I'm just trying to validate that everything is near "normal" position, not so far out that valves hit pistons. You are correct that if 0 on the crank, then "in theory" mechanical timing is at zero if the pulley hasn't slipped due to its bonded design. Cam position is correct, yep. Yes, I meant the mechanical timing of crank vs. cam shaft due to the sprocket being I believe 180 degree out of position. The sprocket doesn't bother me in this position, I just wanted to verify it's alignment. That is what I was looking for in the FSM, an explanation to the distance and side these 2 markings can be in relationship to one another. Thanks, that explains it. Once I get this back on the road, I'll have to potentially play with the sprocket to hone in on the powerband I desire.

NZ, Chain and sprocket are tight per spec with crank pulley set at zero. I was only moving the crank clockwise to align. Can you enumerate a bit more on the after-after adjustment zone. Are you referring to the cam and the sprocket or just the sprocket? From current settings I have posted, can we take a guess where the actual mechanical timing is set at? Also, is the distributor in the correct position? The distributor set screw is at the most counter clockwise position, what does this indicate with the rest of the motor settings?

Rebuilt L28E, unsure if head was shaved, bored out, new pistons, etc. Here is where it sits now, explain to me what the engine assembler was thinking and how it can all be adjusted back to OEM specs. So I set the crank pulley by hand to 0° verifying the piston is TDC, however between 10° and 0° per the crank gauge the piston doesn't move up or down. Here is where the cam gear notch sits: Cam pulley orientation, stamp 3 to the right and stamp 1 lower left corner of pic, obviously 2 is out of the shot: Cam lobes pointed up like bunny ears: Distributor points here and was pointing at plug #1 on the cap. Engine did run, just not smooth: Farther out: So I call the expert builders to chime in and get me to set this all back in order. Thanks for your time and advice, it is much appreciated.

I was considering this, our cams are certainly strong!

Ran out of time to perform a valve adjustment, took me half the day to source a 27mm socket for the crank pulley and a 17mm crowsfoot. But I did test the AFM, results: Measure the resistance from the high side to the low side of the pot/copper trace. (Pins 8 and 6). It should read ~180ohm Mine read: 227.0 ohms Measure the resistance across the "standard"/"Reference"/"Control" resistor. (Pins 8 and 9). It should read 100ohms Mine read: 130.0 ohms Measure the resistance across pins 7 and 8 while moving the flap. It should change. (though it may be jumpy) Mine: Changed and mildly jumpy Repeat this but between pins 6 and 7 while moving the flap. Mine read: same as last test Measure the resistance of the thermal sensor. It should read 2500ohms +/-250ohms@ 68°C Mine: Passed So are these results considered passing or are the impedance's too high for the first 2 tests?

Tony, here's the thing, you are correct. It's even the first thing to do on page 4 of the FSM Engine Tune Up. Unfortunately, I'm going off of what the previous owner described to me which wasn't much other than the motor was rebuilt and the head gasket replaced (date unknown). For all I know with it's 180,000 approx miles the block was bored out and new pistons installed upon said rebuild. I did drive the car home over 3 hours, it didn't overheat and ran fine at highway speeds, I kept it under 3,000 rpms as when I went on it's test drive there was a hesitation/sputtering over that rpm. If it's a valve adjustment/check which should have been performed early into my troubleshooting then I'll get right on it after I complete my retest of the AFM (not starting the motor).

We'll have to see if I get to the valve adjustment tomorrow, have to check and see if I have a 17mm crowsfoot first. I'm going to go through the entire test sweep of the AFM, I may still need to adjust the wiper arm of the vane if voltage is off.

I'm getting there, it's in the plan. Problem is I can't perform a hot valve adjustment bc I can't get a solid idle to even begin to warm the motor up, so I may have to go cold adjust. So I first want to see if anything I cleaned or adjusted has made any difference so far. Thanks for the reminder.

I'll have to source or buy one to verify. After another look what I believe has happened is the A/C compressor has been leaking oil all over the place. The A/C does work and blows cold. This seems logical as there is residue all over the bottom of the distributor and surrounding area where the pulley spins. I also checked under the compressor and found a coating of old oil and new pooling oil about to drip. There should be 3-4.5 oz. in there, I'll have to pull it to confirm and or replace if I wan to keep A/C.

7 hours of work today on the following: Cleaned thermotime and coolant temp sensors again. Torqued down rocker cover and oil pan bolts....both had loose hardware....vacuum leak...eh? Tightened down all intake mani ports. New negative batt terminal. Cleaned power wire to relay bank connectors and fusible links. Checked FPR rubber hose, no cracks, holds pressure, flows fine. Removed AFR to perform calibration check per: http://atlanticz.ca/zclub/techtips/afm/calibration/index.html At 148mL's I get this: Loosen the nut and start to turn the black wheel clockwise, almost 1/4 turn I end up with the wiper arm close to 1/2 way mark. I found several other markings along the wheel from previous attempts to "tune" it. This may have been why I'm running so rich, turning CW gets me back into the lean side. I'll have to confirm with Blue, even though the wiper arm motion is smooth moving to the touch, it was not smooth to calibrate via can/water method. Also comparing this AFM to the unaltered exact internals AFM (used and failed initial FI testing) the tension of the wiper arms are close, but the weights at full turn are about 1/2" away from each other. I believe the lock screw #2 has been touched as well. Next time I'll check the voltage and sweep of the carbon trace.

I'm going to check the AFM spring tension as it may have been clocked and/or tampered with. I cleaned the coolant temp sensor, thermo, and pin connector on the coolant temp housing. The thermo had corrosion on the female pins, going to re-clean them along with the coolant temp just to rule them out. I'm trying to pin down what started this in the first place, when I obtained the Z it started but ran slightly rough, it did die on and off. After a test run, parked and upon restart it was belching white/grey/blue smoke out the tail with this bouncing idle. The Z then got a fuel system cleaning, dumped the old fuel, lines cleaned, new filter, injectors cleaned and tested, new fuel and ran ok until it hit about 3,500 rpms when I felt a loss of power and hesitation. FI bible testing led me to the AFM issue, swapped with another potentially modified/used AFM, same result. Bought a used unmolested AFM, untested, failed some of the FI bible testing. Original which came with Z tested out to be the best from all the AFM's I have. Next I started the inspection, cleaning of the FI harness and sensors. Installed fuel gauge along with everything mentioned in first post and here I am.

I'm not denying this and may resort to the spray technique if all else fails but will still try swisher sweet smoke first.

I do have a mighty vac. May test if all else fails to show 36psi diff. I agree, about 9"-10" manifold to about 30-32psi. I'll still check the FPR hose. Note taken on the AAR hose, I'll try the pinch method you described. All of this won't be tested until tomorrow, so I'll report back with some info or potentially get her running smooth. As for the AFR testing, I have poked around here for info and testing my own: http://atlanticz.ca/zclub/techtips/EFI&fuel.htm

Yes sir, replaced with new pcv valve, hose cleaned and inspected, reinstalled with new clamps on both ends. Prior to this the pcv hose on the block end was loose and bleeding off spraying all over the A/C motor and pulley....quite a mess.

Yes, the connector and the bi-metal element which it's attached to came right out as one. I'm going to check the seal on the AAR again, just for piece of mind. I could even go so far as to pull the AAR off and run a new hose to bypass it all together if its actually damaged...but I don't think its the cause of running rich either. I'll inspect the FPR hose and replace it. So the FPR is non-adjustable, what options do I have for testing it?

Not so strange...upon pulling and cleaning the wiring harness connections and associated components the harness plug on the AAR came off with the harness. This was a potential vacuum leak as it was no longer sealed. I removed the plug with the bi-metal element attached, checked the AAR internal gate for proper operation (was not sticking or stuck) and reassembled the plug/element with some sealant. Doing this actually increased the idle vacuum to where it is now from prior bouncing from 7-10.

I'll have to compare the HG to fuel psi when I have a helping hand, this time I did not. I'll get back with some data if disconnecting the FPR hose doesn't alter anything.

I'll disconnect the FPR hose and advance diaphragm and see what changes occur. Thanks

The AFM bypass screw adjustment had been tampered with prior to me taking the vehicle, no plug was on the AFM either and it may have been clocked as there is some apparent tampering with the guts of the unit. I know its purpose and made some adjustment to ensure it was not open or closed all the way. The Z is not subject to emissions or smog here in IL, so no worries of getting her dialed in for testing at a facility. The AFM is complete, cover removed and all components checked in. Weight is there, but tampering is evident. I have 2 more used AFM's which I tested per the FI bible and neither one is in passing condition. They all look used and tampered with, nor do they make a difference with the jumping idle. I have not held the counter weight to see if it makes a difference.

I don't have access to this, however I may try with the use of a cigar! Smoke machine would help me with determining which seals around the doors, hatch and windows require replacement.....I may look for one now.

I "believe" I have a vacuum leak, I'm not certain. Troubleshooting with the vac gauge is quite common after diagnosing all the FI related equipment, I'm going through the entire process. I'm hesitant to spray fluid all over the motor, smoke seems like a cleaner/safer way as SDgoods stated. I have not checked the fuel pressure regulator, since the fuel pressure is fine, I'll go here next. Temp sensor, cold start and EFI relays passed with the FI bible testing. I did disconnect the cold start and no change to idle.

Is it possible to find a leak without the use of fluids? Also how do you check the underside of the intake for a leak?

Looking for some guidance, suggestions and solutions. Vehicle info: 1978 L28E Rebuilt motor, internals unknown, mileage 180,000 Tested everything FI bible related, all passed. New battery. Cleaned all electrical connections, checked all hoses for tears/splits/etc. AFM idle bypass not calibrated per altitude or emissions, adjusting in or out full makes no changes. New plugs, wires, cap and rotor. Distributor set form previous owner, not turned, set or checked. Fresh fuel and filter, lines purged. First compression test, mildly warm motor, ambient air 35°F, cylinders 1-6: 185,190,190,190,195,190 This seems impressively high, but I'll take it as I thought it was going to be low and inconsistent. Plugs are all black soot to oil fouled, running rich rich rich since purchase. Vacuum Cold Start: http://www.youtube.com/watch?v=eNxDt7UzAoM Vacuum at Idle and blip of throttle: Haven't popped off the valve cover yet, checked/adjusted timing, or if motor is even TDC from previous owner/rebuilder. Due to it being rebuild I want to get a baseline before going off the edge and pull everything apart.. Hopefully once I pull the cover the rest of the head looks this clean: So where to go from here?