can one test the boost compensation with pump on engine? I noticed that that line had popped off and I put it back on and didn't notice any difference. What is it supposed to do? Thanks.
12HT boost compensation operation (1 Viewer)
- Thread starter coldtaco
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Nz Nath
SILVER Star
Something is wrong if reconnecting it didn't give you a noticeable power increase. Either your off boost fueling was turned all the way up (you'd know about it, heaps of black smoke off boost). Or your diaphragm in the compensator has failed.
Can you get to and undo this cap next to the pump fuel inlet? If so you will see the end of the rack, which will move outwards if you move the throttle. If you apply air to the boost compensator from a bicycle pump with the throttle fully depressed, the rack should move another couple of mm outwards, and then return inwards when you disconnect the pump or the air leaks out.
Can you get to and undo this cap next to the pump fuel inlet? If so you will see the end of the rack, which will move outwards if you move the throttle. If you apply air to the boost compensator from a bicycle pump with the throttle fully depressed, the rack should move another couple of mm outwards, and then return inwards when you disconnect the pump or the air leaks out.
- Thread starter
- #3
I will turn back the off boost some more. It puffs black sometimes at first throttle stab accelerating.
I can’t figure out what end of the pump you are showing, looks like the pump is split
I can’t figure out what end of the pump you are showing, looks like the pump is split
Nz Nath
SILVER Star
That’s above the timing case, opposite end to the governor. Where the fuel line from the fuel filter connects.
Didn’t you post in the other thread that you’ve wound your max fuel screw all the way? If the off boost fuel is wound in all the way you’d be rolling some serious coal. More likely that your compensator isn’t working.
Didn’t you post in the other thread that you’ve wound your max fuel screw all the way? If the off boost fuel is wound in all the way you’d be rolling some serious coal. More likely that your compensator isn’t working.
- Thread starter
- #5
The off boost I have not screwed all the way in. Today I have been screwing that back out little by little. So far doesn’t seem to have done much for the black puff. The black puff only happens at original power on after each shift, I would not call what it does as rolling coal. I will keep fiddling with it when I get back again Sunday.
AussieHJCruza
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A puff of black is fairly normal, if you can't see the cars behind you then she probably needs a bit less fuel.
It may pay to check if there is boost at all - if there is no or low boost the boost compensator can't work.
I have seen it not only once that the wastegate linkage has dropped off - leaving the wastegate open and in result very poor boost figures. At least that would be a cheap fix.
that's a good way to check the compensator is working... - I never had that cap off but always wanted to.
You can also use a normal mid sized syringe for that if you can't find the bicycle pump.
Hope that you get that sorted without too much work, Coldtaco
I have seen it not only once that the wastegate linkage has dropped off - leaving the wastegate open and in result very poor boost figures. At least that would be a cheap fix.
Hi mate,
that's a good way to check the compensator is working... - I never had that cap off but always wanted to.
You can also use a normal mid sized syringe for that if you can't find the bicycle pump.
Hope that you get that sorted without too much work, Coldtaco
- Thread starter
- #8
cool, I usually can understand pictures
I was hoping so...any news ? Have you found the culprit ?
- Thread starter
- #10
I haven’t figured anything out yet. As to testing that part in the picture there is no way to remove that when the pump is still on the engine.
Nz Nath
SILVER Star
An easier test then would be to pressurise the boost compensator and see how long it holds pressure for.
A setup like relaxedcruiser shows, or a half decent push bike pump with built in gauge.
A setup like relaxedcruiser shows, or a half decent push bike pump with built in gauge.
- Thread starter
- #12
I’ll keep this in mind. I won’t have time to mess with this some more for maybe two weeks
