Offroad-Express

my mighty big horn lost boost/power on sat night, been sweet then after dawdling around the beginning of the 42 traverse on sat night it seemed to lose power, i replaced the fuel and air filters today and no change, the turbo used to come in about 12-1500 rpms but now about 2500rpm, it is fuel problem i think as it is blowing less black smoke also,the little mesh filter in yhe pump is not there so maybe crap in the pump? motor is still sweet never been hot done 448000ks but recond about 30000ks ago, starts instantly like always, will pull intercooler off tomorrow and start looking for missing broken vacumlines ans that sort of stuff, is a 2.8 td irmisher thing, cheers
vaughan

Also check it doesn't have a boost leak. It may have one in the inter cooler or the boosted side of the intake. This would make your turbo over boost but would loose power. Vacuum test it.

yeah and as you said it could well be a fuel pressure loss due to blocked lines or something but if you've changed the fuel filter it should be alright. Blow some compressed air in the in to the fuel filter housing to blow back down the lines in case its picked some crap up from the tank. Remember to bleed it back up though

Dan

well it seems alright now , went through and re placed the 12 million vacum hoses by parking mine beside one at the wreckers and swapping them over.what mods can you do to these for more power, mainly for towing, i plan to remove all the emission crap next week and a better muffler, what sort of boost is safe . cheers
vaughan

spanky wrote:well it seems alright now , went through and re placed the 12 million vacum hoses by parking mine beside one at the wreckers and swapping them over.what mods can you do to these for more power, mainly for towing, i plan to remove all the emission crap next week and a better muffler, what sort of boost is safe . cheers
vaughan

Get some gauges (boost and exhaust gas temp), put the exhaust probe in the manifold upstream of the turbo.
Leapfrog the fuel and boost until you've got the power you want without blowing head gaskets.
750C is the highest EGTs you ever want to run, put your own safety factor on that.

After the above, you can also advance the injection pump timing and they respond very well to a 2 and 1/2" bigbore ex turbo. Not hard to gain extra 30-40hp. My last one ran to 155hp on dyno and 340nm torque and ran at this level of tune for 95,000ks no trouble.