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Engine Specific Info and Questions => mTDI Mechanical TDI Conversions => Topic started by: snakemaster on July 05, 2012, 07:35:55 pm
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this has hapend on two mtdi pumps i have built , when you press the diesel peddle hard to the floor from 1200rpm in 5th the engine seam to go on to two cylinders its like it fires of the injectors before there ment to fire and lots of smoke from the exhaust(when it is on two) and can take 70 seconds to get back on 4 cylinders , i run a 1z mtdi with 110hp injectors FMI and a gt 15 with no pipe going to the wast gate 32psi max ,boost spike ?, will do the same in second gear to third etc,pump timming and the advance curve fine , i would like to find out what is causing this and get it sorted , its beating me i have put a we faset elec pump in line but makes no difrance .
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I think the issue is that you are trying to shove that much fuel in to the cylinder when there is not enough air.. 1200 rpm is dangerously low to be mashing the throttle.
a GT15 at 32 psi? You gonna blow that thing up too.. Pretty sure those are NOT suited for more than 18psi tops, much like the K03's.
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the same thing happings if your steady with the throttle at 3000rpm and then floor it , i dont hit 32psi often 4 years with the same small gt 15 , at 55 on a flat road 4 to 6 psi , and i get good MPG 65 sitting at 55mph UK gallon
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What sort of setup do you have for the pumps? What did you build them out of?
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What sort of setup do you have for the pumps? What did you build them out of?
11mm head +di camplate , shimed gov 2mm , control leaver 2mm more than std , mod lda, vw adv set up , i have a control leaver with 4.1mm and this pump is worse than the other one , seams to get more presshure to the injectors sooner , its like it has starved its self off fuel but its not and two of the injectors are fireing off at the wrong time , and if you take your foot of the thotle it sorts its self after 30 seconds its a strange one .
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What is the 4.1mm in reference too? the amount of throw your internal throttle has?
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the travel of the control spool has with the moded control lever is 4.1mm
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Ahhh, well I honestly think you are just trying to ingest wayyyy too much fuel at too low of an RPM. I know if i stomp the pedal at low rpms for whatever reason (not normal driving), it really bogs down and I can feel the engine having a hard time with what I have just made it do. I am unsure of my control levers travel, but it is quite a bit.
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I'll try to help you with brainstorming because Im no expert about ve's Ive never owned one. Only taken them apart and read about them. So say this happened to my p pumped truck I would think its one of two things. One would be it sounds like a timing issue. The thing your describing sounds like when a staticly timed pump slips timing or maybe has way to much timing. I know these pumps have a timing advance in them so possibly this is in some way not working properly. The other thing that can cause these symptoms are inadequate fuel pressure or air leaks. Could be a clogged filter, a crack in a fuel line or a pick up tube, or just plain lousy pressure from the lift pump. Does this car have a fuel pressure gauge? My other idea was valve float, but thats not it at those rpms.
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HOLY FU**
GT15 to 32psi? can you say "whole lotta hot boost"?
you need a bigger turbo.
and to rev your engine up more before mashing the throttle. 1200 is barely off idle.
my engine backfires if i hog down at too low of an RPM..
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HOLY FU**
GT15 to 32psi? can you say "whole lotta hot boost"?
you need a bigger turbo.
and to rev your engine up more before mashing the throttle. 1200 is barely off idle.
my engine backfires if i hog down at too low of an RPM..
only once in a blue moon dose it see 32psi , 6 to 12 psi is the norm and have a big FMI so no hot air , one pump has a high lift idi cam plate , and other one has a disco camplate with the 4.2 mm of travel on the control spool and that one is the worst ,if i am giving some brisk driving but not hard ,this running on 3 to 2 then back to 4 after 30 seconds and happings at 4500 rpm, have fitted a we 3psi faset lift pump but no diffrance.
it is none of theas inadequate fuel pressure or air leaks. Could be a clogged filter, a crack in a fuel line or a pick up tube, but it is like it fires of 2 injectors before it is ment to , my timming addvance set up is from a 1.9 tdi pump with all the shimes and the spring so cant jump timming addvance , will try a shim in there and retard my timming a tad see if this makes a diffrance
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Does this car have a fuel pressure gauge?
This sounds like an excellent idea.
Have you measured the internal pump pressure when you are mashing the go pedal?
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Does this car have a fuel pressure gauge?
This sounds like an excellent idea.
Have you measured the internal pump pressure when you are mashing the go pedal?
no i dont, but wont take me to much to rig up , what psi rpm are we looking at 1000 rpm 18psi ? and higher with the rpm going up , some one got some figures
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In your situation I would just be looking to see if the pressure is significantly dropping when you are mashing the pedal. If it is, you know you don't have enough supply flow.
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got the gauge on and at idle it is 80psi , 3000- 3500 rpm when it cuts to 3 it reading 120psi it is steady from 80 to 120psi with no drop then it cuts to 3 , and when it popes back to 4 you hear the injector cracking like it is bleading its self , there is a good bit of gray/black smoke coming from the exhaust when she goes down to 3 .
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"Pressure in pump MUST be 43.5 Psi at 1000 RPM engine "
"Pressure at 2000 Rpm -about 75.4 Psi"
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tryed on a aaz pump 45psi at 1000 engine rpm , and on 3 of my M tdis are all 80ish psi at 1000 engine rpm 2 off the pumps are built from landrover 200 tdi pumps all parts swaped over and rebuilt the same spec + gov mod and lda , i have a range rover tdi stock one so i will put the gauge on it and see what it reads .
i have put biger injectors in one of the M tdis .216 and will change the PRV so i get 45psi at 1000 rpm and see how she goes
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GOT it down to 50psi at 1000 engine rpm and biger injectors and no difrance 3000-3500rpm when it cuts on to 3 ,120psi on the pump when she cuts on to 3 , ??? any thoughts what could be causing this
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i stuck in a nother set of injectors with bigger nozzles and it dont cut down to 3 untill higher up the rev range ,so its a bit beter, just thinking could i be over pressurizing the injectors , so making tham stay open a little ,190bar thay are, this would explain the smoke from the exhaust when it goes on to 3 and 2 cylinders , dose this make sense
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Weak valve springs, improper lifters, high boost and high oil pressure can cause this. High boost and rpm help to float the valve and high oil pressure overextends the lifters. This holds the valves open causing misfire and huge white smoke. Recovery takes several seconds at low rpm My TD would do this in the cold (80psi oil pressure) at high boost and revs, car would stall completely and not restart until the lifters bled down, 1 minute or so. Scary the first time it happened.
Make sure you are using correct lifters for the valve springs. Older 8mm stem dual spring heads used different lifters than newer single spring, 7mm stem heads. Old lifters will pump up easily with single springs.
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Weak valve springs, improper lifters, high boost and high oil pressure can cause this. High boost and rpm help to float the valve and high oil pressure overextends the lifters. This holds the valves open causing misfire and huge white smoke. Recovery takes several seconds at low rpm My TD would do this in the cold (80psi oil pressure) at high boost and revs, car would stall completely and not restart until the lifters bled down, 1 minute or so. Scary the first time it happened.
Make sure you are using correct lifters for the valve springs. Older 8mm stem dual spring heads used different lifters than newer single spring, 7mm stem heads. Old lifters will pump up easily with single springs.
nice one ,i will look in to this ;)