keithanc Posted June 17, 2009 Share Posted June 17, 2009 Customer recently brought in his Mack E-7 350. Truck model is a CH613. Original complaint was hard starting and lack of power. Checked compression at a few cylanders, found low compression at 6,5,and 3. Rebuilt the motor, liners, pistons, rods, re-man heads from re-mack. Side note; heads were build without valve stem seals, called re-mack, they advised truck didn't need valve stem seals. Found out later from Mack, that in fact this truck absolutely needs them. I am having issues with engine surging at idle, wants to smoke at higher rpms, smells like fuel, installed new injection pump. Still having same problem. Engine almost stalls out after throttle depressed from high rpm. When surging it's around 650 to 900 rpms. Any suggestions? Quote Link to comment Share on other sites More sharing options...
fjh Posted June 17, 2009 Share Posted June 17, 2009 Customer recently brought in his Mack E-7 350. Truck model is a CH613. Original complaint was hard starting and lack of power. Checked compression at a few cylanders, found low compression at 6,5,and 3. Rebuilt the motor, liners, pistons, rods, re-man heads from re-mack. Side note; heads were build without valve stem seals, called re-mack, they advised truck didn't need valve stem seals. Found out later from Mack, that in fact this truck absolutely needs them. I am having issues with engine surging at idle, wants to smoke at higher rpms, smells like fuel, installed new injection pump. Still having same problem. Engine almost stalls out after throttle depressed from high rpm. When surging it's around 650 to 900 rpms. Any suggestions?Mack E-7 350. electronic governer ????If so you may have a econovance issue.If not electronc try running the engine from a pail of clean fuel it may be sucking air. Quote Link to comment Share on other sites More sharing options...
keithanc Posted June 17, 2009 Author Share Posted June 17, 2009 Mack E-7 350. electronic governer ????If so you may have a econovance issue.If not electronc try running the engine from a pail of clean fuel it may be sucking air.This truck has a Vmac II installed electronic control module. I ran some clear tubing from external fuel supply and no bubbles. How does the econovance work on this thing. It's a 97 model year truck. Thanks. Quote Link to comment Share on other sites More sharing options...
keithanc Posted June 17, 2009 Author Share Posted June 17, 2009 This truck has a Vmac II installed electronic control module. I ran some clear tubing from external fuel supply and no bubbles. How does the econovance work on this thing. It's a 97 model year truck. Thanks.What I mean by how does it work I mean how does it advance the timing, is there a way to check at high idle how much the timing is advanced. Quote Link to comment Share on other sites More sharing options...
fjh Posted June 18, 2009 Share Posted June 18, 2009 What I mean by how does it work I mean how does it advance the timing, is there a way to check at high idle how much the timing is advanced.The econovance is electric over hydralic it runs off oil preasure!Start the engine it should stutter and stumble till the oil preasure comes up then clean up if its not doing that the econovance solnoid is likly fubar!You need a pro link or computer to watch the timing .Simular post to yours http://www.bigmacktrucks.com/index.php?showtopic=9600 Quote Link to comment Share on other sites More sharing options...
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