Hi everyone, long time reader here. Does anyone know if this is too much play for a properly torqued intake cam gear? I keep having timing issues even though all 5 marks say they are inline. I suspect the gear isnt supposed to move that much since none of the others do, any idea on what the root cause would be? Is it repairable? (I see replacement gears arent cheap. Thanks in advance!
Well after testing all morning here is what I've found. If i line up the timing belt properly (lines on belt with marks on gears), i get interference after about a 300 degree turn (once the p side intake cam gear has traveled about 95% of a full turn). Moving the p side intake cam gear counterclockwise (so now my belt timing mark is 1 tooth to the right of the sprockets' mark) and ensuring all other timing marks are still good, I still get interference about the same spot. Now, if I continue to move the p side intake cam gear counterclockwise as described above, lining the belt up 3, 4, 5, and even 6 teeth to the right I can rotate the crank fully 720° without any issues. With this knowledge, I believe if I can set my p side intake cam gear by the actual cam position (not the gear/sprocket) by way of removing the valve cover and lining up my timing there. Can anyone tell me (show me) how a p side intake cam rests in tdc position?
Actually, since the block is at tdc for cylinder 1, would the correct camshaft position be when cylinder 1 lobes are pointing straight up?
There should not be any “slop” where the sprocket is able to move freely on the end of the cam shaft. You may be missing the dowel that locates the sprocket into the cam, or the gear may not be installed correctly. What is the back story?
With the video showing the center bolt rotating with the sprocket, the movement is transferred to the cam and the free-play is due to the lobes for two cylinders running up against the opening and closing ramps on the lifters. Here's the timing belt alignment from the FSM. If you're doing all of this properly and still have an interference problem, I would remove and verify all cam sprockets are properly registered on their camshaft dowel pins, if that doesn't work, check for foreign debris in the engine.
Now I'm not getting any interference on the properly aligned timing marks. I'm thinking maybe a valve got stuck open and that's what I was hitting before? My overarching problem still remains though, i cant get the car to start... It is timed right, it cranks, it has fuel, it wont startup... I'm finishing my build here and have just put in a new wiring harness and new 2nd gen ptu w/ harness so I dont believe it's a wiring issue or ptu related. I confirmed that I have all earth/grounds connected. I checked the CAS by rotating the shaft and heard the "clicks" of each injector functioning. All new OEM spark plugs. Even took them out and cleaned them after the no start (they were soaked in fuel) I just dont know what else to check. A special note, I did just install a haltech ecu so i cant pull the oem diagnostic codes (the haltech isnt throwing any codes either). Any advice? Btw: I'll be happy to share my build with the forum just as soon as I get this wrapped up and running again
Did you check for spark on each cylinder? Did you check compression before removing the timing belt? You mentioned a Haltech ECU -do you have an appropriate map loaded for you injectors?
Update here: I've got no effin clue anymore. Just went through my 3rd PTU!!! I've checked, double checked, and fuckin triple checked all my grounds! Plenum ground by cylinder 5 check. Plenum ground by cylinder 6 check. Body ground by fusebox check. Battery ground attached to transmission check! WHAT THE ACTUAL FUCK! Just about ready to abandoned this entire fucking build over this shit!!! Apparently everytime I try and start my car I fry a $200 PTU. FML
Has there been a ptu upgrade from s1 to s2 done. And if so was it a plug and play or a solder job. if soldered check the wiring. Intros swap there can be 2 black wires one of them is a ground the other is a n injector power feed if the are wired wrong that sends a powered feed from the ptu direct to earth and can cause the ptu to get very hot and fry. it's a long shot from the info given but it is the only way I know of to fry ptus constantly
How are you determining that the PTU is fried? Have you checked continuity on both sides (ie ECU to PTU and PTU to coil)? Either it is not earthed (and you will not have continuity between the Earth pin & the negative terminal) OR you have a dead short (and you will have continuity where you should not). It would be helpful if you posted the results of diagnostic attempts otherwise we (anybody reading and wanting to help) are flying blind.
Hi everyone, update here. I was testing the PTU as described in the '94 fsm since it is an S2. I was under the impression that if the ptu failed any of the tests, then a replacement was needed. However, I have learned that isnt necessary the case. Apparently the ptu can fail a test for one side of the polarity and still pass the other side of polarity and be functional. Anyways with a new ptu in hand, and all grounds visually inspected and confirmed with a multimeter for resistance, I attempted to start the car and as usual it started and promptly died. I still suspected the p side intake cam gear to be the problem so this morning I've removed the valve cover, gear, and camshaft only to find the dowel pin on the end of the camshaft has broken off causing the intake cam to not be in time. Inspection of valves through the lower plenum show all 6 p side intake valves stuck open. I'm guessing those are all bent now? Even after removing the cam they still dont come all the way back up to close. Definitely gonna have to order a camshaft dowel pin (wish I knew about those during my rebuild), a new head gasket, and possibly 6 new valves. Sucks for sure, but I do at least feel somewhat better knowing what the freaking problem was.
Where do you live Cliff? A little face to face help from members of this forum may save you heaps of pain and money.
