sending the high pressure pump and injectors in for rebuilding------again. like to have never got the injectors out, lu
cky i didn't break em.

How many hours on your HPDI? And what size/year/model?

Thanks

02 200hp with 1000 hrs. got it back together and now won't do but 4300 rpm. will try to get diagnostics run on it today. acts like one cylinder isn't firing. I'm beginning to think hpdi is a 4 letter word.
want a new engine, but just can't make myself give up on a engine with only 1000 hrs. mechanically it's a great engine, just the fuel transmission system really sucks. wish there was a way to convert it to carburater system.

got it goin---for now. found a broken spark plug wire, must have been damaged while the coils were hanging out of the way. wot is 5800. ran it at 4000 for 40 min with no problems. hopefully i'm good for another year.

well, back to the drawing board. ran great all week end. went out Monday for a 25-30 mi run and on the way back it acts like it's out of gas, stalls out and stops. i can pump the bulb and fire it up and it runs great. first time it ran good for about 2 mi, then 1mi, then about 3/4 mi. the bowl that is in line before the vst has fuel, so it's not a tank/supply problem. i'm thinking a vst problem. i guess i'll change out the entire vst tank, pump and float assymbly to see if that's it. have access to another engine with a blown cyl.

good luck...I hope the vst wasn't the problem on the blown motor....

Wait...you said you could pump the bulb and it would fire back up, your bulb should stay hard. If you can pump the bulb and it never gets tight tou have either a bulb problem or a low pressure diaphram bad.

one of the low pressure pumps could be bad, but they are both new(6 mo). i replaced them first, before i did the injectors and hp pump. the bowl is full of fuel. replaced the paper filter in the bowl and ran it at 4000 for 20 min today with no hiccups. we'll see tomorrow. have 2 grandkids coming to do a jetty trip.

HP pump either works or it doesn't Its a mechanical pump not a diaphrame
A report can tell you what your getting


Only issues I ever had out of one was the secret filters that were "non serviceable"
Although you can change them out in 20 minutes and 6 dollars

hp pump has about 4 hrs on it since rebuild. not worried about it. thinking i have a blockage somewhere. if the other vst works, i'll know it's in the vst system.

Is your fuel tank vent clear?

Also, when you had the motor off rebuilding did you look at the tuner? If it is melted it can cause alot of those type problems.

Also, what pistons did you use for rebuild cast or forged? I had a buddy get a engine from a rebuild place that used the wrong ones and it done the same thing. The pistons would heat up faster than the cylinder walls and would expand and it wouldn't turn RPM and would even die and temporarily sieze.

The pistons heat up faster than the cylinders in all motors. That is the reason for cold piston skirt clearance needing to be at least .001 per inch of bore. Cast pistons need more clearance .0015 per inch of bore.