how to stabilize map sensor vacuum

rkassed · Post by **rkassed** » Fri Sep 11, 2009 3:12 am

hi all, i am trying to tune my ignition on the road and the timing jumps around because the load keeps moving. is there any way to stabilize this? i dont think its an electrical thing, but has anyone else experienced this?
Randy

NITROPIXIE · Post by **NITROPIXIE** » Fri Sep 11, 2009 6:07 am

I think you just need a really steady foot on the accelerator and find some really straight roads with consistent gradients. It is much easier o a rolling road as you can keep the consistency to tune the map. Otherwise its just persiverence.

Broke4speed · Post by **Broke4speed** » Fri Sep 11, 2009 3:48 pm

I use a .030"-.025" MIG tip in the main vacuum line, works wonders

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NITROPIXIE · Post by **NITROPIXIE** » Fri Sep 11, 2009 4:53 pm

How did you attach that?? Did you Tee it off just before the MAP sensor

Post by **brentp** » Fri Sep 11, 2009 5:57 pm

Be sure to review these resources for stabilizing your MAP readings:

http://www.autosportlabs.org/viewtopic.php?t=1171
http://www.autosportlabs.net/MJLJ_V4_ve ... _operation

cng1 · Post by **cng1** » Fri Sep 11, 2009 6:01 pm

You don't tee the MIG tip into the vacuum line, you just shove it a few inches into the hose from the engine end and clamp it down with a jubilee clip.

We have also found that mini-moto fuel filters (cost about a dollar/pound/euro) are ideal as a damper.

Gassed'58 · Post by **Gassed'58** » Wed Sep 23, 2009 8:37 pm

When I was trying to get the best sized vacuum reservoir for my set up I used a large plastic syringe .

I plumbed it into the vac line with a " T " piece and by pushing or pulling the plunger in or out I was able to adjust the volume of the reservoir in a matter of seconds. This means that the testing of differing sized reservoirs is speeded up no end as you don't have to keep making test pieces or scrabbling around trying to find suitable sized containers and plumbing them in.

If you use a new syringe then the friction of the plunger in the syringe will keep it in place during testing.

When you find the volume of reservoir you are happy with then all you do is read off the size on the side of the syringe. You can then make one that size.

I got my large syringe from the local farm stores - injecting cattle - but if you struggle to get one large enough then just T in several small ones.

Simple but effective.