Mbmaring Posted February 14, 2008 Share Posted February 14, 2008 I picked up a 1999 mack e7 with 350,00 miles and it says 400 HP on the valve cover. It seems a little week on power I hooked it up to my empty end dump and it doesn't seem to have much power in 10 gear and I think my series 60 360 hp seems to have more power. Is there anything simple besides a fuel filter I could check? Is it possible to change hp on these without too much work? Quote Link to comment https://www.bigmacktrucks.com/topic/3421-1999-e7-400hp-power-shortage/ Share on other sites More sharing options...
Mackpro Posted February 14, 2008 Share Posted February 14, 2008 Does it have a manifold (turbo boost) pressure guage in the dash. If it does it should read 21-27 psi under a hard pull. If it doesnt have a guage you can get a low pressure air guage 0-50 psi and run a 1/4 inch plastic air line from the intake manifold up into the cab and hook it to the guage and run it down the road. We do this all the time to check boost pressure. The intake manifold is on the driver side of engine and has a 1/8 inch pipe plug in it, install your fitting/hose there. Does it black smoke under a load? Check air filter also. Fuel pressure is also key with an ETECH engine. Quote Link to comment https://www.bigmacktrucks.com/topic/3421-1999-e7-400hp-power-shortage/#findComment-17037 Share on other sites More sharing options...
Mbmaring Posted February 14, 2008 Author Share Posted February 14, 2008 It does not smoke at all I will try the boost gauge and fuel filters. Is there a way to check fuel pressure or do you need to take it to a mack dealer and hook it up to a computer. Quote Link to comment https://www.bigmacktrucks.com/topic/3421-1999-e7-400hp-power-shortage/#findComment-17038 Share on other sites More sharing options...
fjh Posted February 15, 2008 Share Posted February 15, 2008 It does not smoke at all I will try the boost gauge and fuel filters. Is there a way to check fuel pressure or do you need to take it to a mack dealer and hook it up to a computer.There is a plug on the front of the block right in front of the fuel pump gallerys screw in a 2 inch 3/8 pipe close nipple and an elbow with an aproprate sized fitting to adapt a guage to you'll need a 0 to150 gauge to do (this also can be used for boost) your looking for 60 to 100 psi fuel preasure.if you have no smoke and below posted spec boost be looking at a fueling issue 25- 30 boost is a warm good running 400. Quote Link to comment https://www.bigmacktrucks.com/topic/3421-1999-e7-400hp-power-shortage/#findComment-17045 Share on other sites More sharing options...
Gambi80 Posted February 15, 2008 Share Posted February 15, 2008 There is a plug on the front of the block right in front of the fuel pump gallerys screw in a 2 inch 3/8 pipe close nipple and an elbow with an aproprate sized fitting to adapt a guage to you'll need a 0 to150 gauge to do (this also can be used for boost) your looking for 60 to 100 psi fuel preasure.if you have no smoke and below posted spec boost be looking at a fueling issue 25- 30 boost is a warm good running 400.I don't get 30lbs of boost w/my 427. Quote Ever wonder how a blind person knows when to stop wiping? Link to comment https://www.bigmacktrucks.com/topic/3421-1999-e7-400hp-power-shortage/#findComment-17065 Share on other sites More sharing options...
fjh Posted February 16, 2008 Share Posted February 16, 2008 25- 30 boost is a warm good running 400your 427 will likly hold on longer than the 400.the torque curve is relitivly flat.Year of unit makes a pile of diffrence too .It seemed as the emmisons got tighter the horse power seemed to shrink!NO ONE would ever admit to it but Im sure thats how it worked.once the buy off went down with the EPA and what have you we noticed some power come down the pipe for a bit! there weredata files that would actually put out. the XP file was avalible for the eteck for a real breif period aprox 2 years.that got nipped back real quick. Quote Link to comment https://www.bigmacktrucks.com/topic/3421-1999-e7-400hp-power-shortage/#findComment-17067 Share on other sites More sharing options...
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