Low73620 Posted September 20, 2015 Report Share Posted September 20, 2015 So here is the deal, I installed a new mechanical fuel pump after my electric pump was giving me issues. Drove a half mile and the eccentric came loose on the cam. I then removed the valve cover and tightened the bolt. Well seems I bent the fuel pump plunger. After messing with it for a while i decided to go back and just replace the efp instead. Now while the valve cover was off I put the motor to no1 and checked timing marks on the cam gear. Looks good. I have spark and fuel and still no fire. No pop or anything. Any ideas what could have happened by the eccentric cam gear from coming loose? Quote Link to comment
flatcat19 Posted September 20, 2015 Report Share Posted September 20, 2015 Suck, squish, bang, blow. What's missing? 1 Quote Link to comment
Low73620 Posted September 20, 2015 Author Report Share Posted September 20, 2015 Sorry forgot some vital info. L16 with Weber 36/32 Quote Link to comment
datzenmike Posted September 20, 2015 Report Share Posted September 20, 2015 The bolt can't come loose, no way. They are torqued to 90-110 ft lbs. It ain't coming loose So you must have put it on with the pump. Or taken it off with the old pump and had to put it back on. (both unnecessary) Or at some time in the past the cam sprocket was removed, perhaps for a head gasket replacement and not properly tightened.. Can't see how the pump arm is bent as it's bent looking to begin with and moves to follow the eccentric. Was the sprocket loose on the bolt? Wobbly? or just loose enough for the eccentric to slip? If loose enough the sprocket could have 1/4 turned to the next dowel hole. The TDC and ignition timing would still be unaffected but the valve timing would be insanely out, possibly enough for open valves to hit piston tops at TDC. At TDC are the number one valve lobes at 10 and 2 o'clock??? as viewed from the front If everything is right... look down the carb and pump the gas. You should see strong squirts of fuel. Got spark??? If everything is there it's likely flooded from the new pump. Look at the sight glass on the front of the carb. Is it over filled or at the mark on the glass?? 1 Quote Link to comment
banzai510(hainz) Posted September 20, 2015 Report Share Posted September 20, 2015 there is spacer for the mecha fuel pump so it don't bend the arm Bolt is 100pounds no way come loose if loose then get a wrench 100pounds get spark? Get fuel in carb. gas squirts in when cycle linkage? timming should not change. why would it did you do something? Quote Link to comment
KoHeartsGPA Posted September 20, 2015 Report Share Posted September 20, 2015 Pretty much what the guys said before me, make sure all vital parts are torqued to specs, very important! Quote Link to comment
datzenmike Posted September 20, 2015 Report Share Posted September 20, 2015 fuel pump.. gasket.. plastic spacer..gasket..head 1 Quote Link to comment
Low73620 Posted September 20, 2015 Author Report Share Posted September 20, 2015 Looks like the spacer is missing. Probably why the pump arm bent. When I bought the truck the EFP was already installed. There was a block off plate on the head. Until recently, I never found the EFP a problem, always seemed to provide adequate fuel with low pressure for the Weber. Turns out there was an inline fuel filter before the pump that was clogged. I'm going to have to remove the Valve cover again an check the location of the cam lobs. I just checked the timing marks. Quote Link to comment
Low73620 Posted September 21, 2015 Author Report Share Posted September 21, 2015 Well looks like the gear did jump. Definitely not at 10-2. Is this tricky to put back? Quote Link to comment
flatcat19 Posted September 21, 2015 Report Share Posted September 21, 2015 Research blocking your chain before you ask anymore questions. 2 Quote Link to comment
datzenmike Posted September 21, 2015 Report Share Posted September 21, 2015 Good point. Block the tensioner. Use the search function for details but DO NOT remove the cam sprocket until you do. When safely blocked and at TDC, lift the sprocket away but keep the chain on, rotate the cam with vice-grips until the aligning dowel pin (hopefully it has not sheared off) fits in the #1 hole and the cam lobes are at 10 and 2. Quote Link to comment
Stoffregen Motorsports Posted September 21, 2015 Report Share Posted September 21, 2015 I hear death bells. A motor that slips it's cam sprocket is more than likely going to have bent valves. Quote Link to comment
banzai510(hainz) Posted September 21, 2015 Report Share Posted September 21, 2015 I really dont belive it slippd a tooth research more before taking things apart. Just buy a new fuel pump and I think the aftermarket ones come with the spacer. https://vimeo.com/19077890 Quote Link to comment
Low73620 Posted September 25, 2015 Author Report Share Posted September 25, 2015 Well it did slip a tooth and i must have been really lucky. because after putting it back, it fired right up! Thanks datzenmike and all who replied... Ratsun saves the day, again! 2 Quote Link to comment
Stoffregen Motorsports Posted September 25, 2015 Report Share Posted September 25, 2015 Glad you caught it in time. Quote Link to comment
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