MAP signal problems
12-09-2008, 11:40 PM
#1
Tour de Franzia
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MAP signal problems
I have a vac hose from the front of the manifold, into the car, with the boost gauge "T" about 1' from the computer.
Do I need to rethink this, or do the little fuel filter on the vac line?
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12-10-2008, 12:02 AM
#5
Boost Pope
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The FPR line is an excellent place to take the MAP signal from, as is the brake booster line. I tee'd the rubber brake line just before the checkvalve, which made for a very convenient run through the unused rubber plug in the firewall next to the speedo cable.
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12-10-2008, 12:05 AM
#7
Yeap, agree to the above post. I used some tiny *** small vacuum line to help smooth the signal going to MS. Like really really small ID. And the line is ~8' long too as it runs from the port Chad described to under the car, and comes up under the passengers seat area where my MS2 is. It did help smooth the signal a bit, though I still get electrical noise on it.
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12-10-2008, 12:31 AM
#8
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My MAP looked similar when I had the line at the front of the IM. I did the recommended fix of teeing it off the FPR and added a small inline filter (HD/Lowe's has several in the lawn mower parts section) and that smoothed it out nicely. It didn't cause the engine to run much differently, but VE analyzer in MLV seems to work a bit better without the 3-4 kPa fluctuation bouncing it between table cells. I also recall that MAP fluctuations may have been triggering someone's MAPdot accel enrichments, but you shouldn't have that problem if running TPS-based enrichments.
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12-10-2008, 11:40 AM
#9
Boost Pope
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When I was running an EMU, I initially used 3/16" (I think) rubber vacuum hose coming directly off the back of the manifold and into the MAP sensor. The signal was very noisy- lots of peaks. I later changed this so that the MAP sensor was teed off the line that was feeding my boost gauge, which involved several feet of ultra narrow semi-rigid plastic tubing and compression fittings. The signal immediately smoothed out.
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12-10-2008, 02:21 PM
#10
This is how mine has always been, guess thats why I don't have issues.
There is much truth here.
When I was running an EMU, I initially used 3/16" (I think) rubber vacuum hose coming directly off the back of the manifold and into the MAP sensor. The signal was very noisy- lots of peaks. I later changed this so that the MAP sensor was teed off the line that was feeding my boost gauge, which involved several feet of ultra narrow semi-rigid plastic tubing and compression fittings. The signal immediately smoothed out.
When I was running an EMU, I initially used 3/16" (I think) rubber vacuum hose coming directly off the back of the manifold and into the MAP sensor. The signal was very noisy- lots of peaks. I later changed this so that the MAP sensor was teed off the line that was feeding my boost gauge, which involved several feet of ultra narrow semi-rigid plastic tubing and compression fittings. The signal immediately smoothed out.
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01-20-2009, 11:38 PM
#12
Tour de Franzia
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my **** is acting up again:
and from the same log, nothing changed:
i have the very tiny vac hose goes from the FPR line, then a T for the boost gauge, then to MS. What am i ******* up?
and from the same log, nothing changed:
i have the very tiny vac hose goes from the FPR line, then a T for the boost gauge, then to MS. What am i ******* up?
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01-21-2009, 02:54 PM
#13
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go to home depot and get a mig welding tip--the largest wire hole they carry. put it inline with the signal. it may only be a .030 hole and you may want to drill it out to .040 or .050 so get those drills too.
what wastegate are you running? it might also be doing that since that's how they work.
what wastegate are you running? it might also be doing that since that's how they work.
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01-21-2009, 10:27 PM
#14
Tour de Franzia
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go to home depot and get a mig welding tip--the largest wire hole they carry. put it inline with the signal. it may only be a .030 hole and you may want to drill it out to .040 or .050 so get those drills too.
what wastegate are you running? it might also be doing that since that's how they work.
what wastegate are you running? it might also be doing that since that's how they work.
I have the wastegate connected directly to the compressor nipple. Should I put a nipple on that and go of the vacuum bank in the brake-line?
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01-27-2009, 10:32 PM
#20
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On the topic of the inline fuel filters, I went to HD and they did not have any fuel filters for lawn mowers at all. Went to OSH and found only one - intended for a 1/4" or 5/16" ID line... kinda big but I bought it as I couldn't find any others. Anyone have a better source for these that works with smaller vac line?
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