Ray-73 914 FI Problems
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raygreenwood
- Posts: 11907
- Joined: Wed Jan 22, 2003 12:01 am
Drop into a plastic supply and beg a very short length of 13mm (1/2") plastic rod. Polypropylene, delrin, nylon,...most anything will do. You could even use metal. Make a piece maybe 1/2" long. Drill a hole in it. 3-5mm. Start with 3mm. Pull the red 12mm hose out of the elbow on top of the PCV valve where it attaches to the oil breather. Shove the plug with the hole in it into the hose about 1". Then attach the hose, adjust your idle and check your fuel mixture. Also make sure that the PCV system is complete and running properly. It runs from the side of the air cleaner...is drawn through a strange looking T-fitting (its atually a flame trap)...is split into two hoses...one to each head. Its drawn through the rocker boxes....through the pushrod tubes into the crankcase....out the oil breather into the manifold. You must have some flow. The small hole in the plug allows a constant...but predicatble flow. That way you can tune around the slight change in fuel mixture and idle. It keeps the engine clean...and actually cools the heads a few degrees. ray
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TOPGUN63
- Posts: 17
- Joined: Thu Oct 02, 2003 3:43 pm
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Dave_Darling
- Posts: 2534
- Joined: Thu Apr 27, 2000 12:01 am
There's a procedure on the Pelican Parts website, under 914 Tech Articles. Also check the Brad Anders D-jet site, http://members.rennlist.com/pbanders .
--DD
--DD
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raygreenwood
- Posts: 11907
- Joined: Wed Jan 22, 2003 12:01 am
Sorry for the delay. The throttle position sensor adjustment in 90% of the books...is incorrect. The problem is that they usually get hung up in the differences between late and early sensors...and usually are talking about adjusting the late sensor while they show you a picture of the early sensor.
I think I have a post on this already.
(1)Remove the TB from the plenum.
(2) Hold the TB in your left hand...with the outside side (air filter side)...facing your right.
(3) hold it upside down with the TPS facing you....black cap off.
(4) Loosen...just barely, the locking screws.
(5) with your left hand, grip the TB...with two fingers, or your thumb pushed inside from the plenum side...to hold the plate tightly closed.
Now...this is going strictly from memory...so check the connector numbers. But...you need to connect a VOM onto connectors 17 and 22....I think. Set it on continuity. We are just checking for connection. Resistance...unless it is just extremely high...is NOT a factor on the D-jet TPS. The D-jet TPS is simply a series of on/off switches.
Now...rotate the TPS body toward closed. That means....that as you look at the guts of the TPS...the wiper arms are down near one end of the curved circuit. You want to rotate the plate until the wiper drops off the very last one. On some models..you may even see a little square "parking" area etched into the circuit for the contact tip....at least this is what I call it. I am having you do this just so you know the complete range.
This causes the little pair of floating "whisker" switches that contact the two brass posts...up in the top of the arm...to be overly closed.
Now...rotate the plate....still keeping the throttle plate tightly closed....in the opposite direction....until the tip of the wiper arm is just paused like about .005" before making contact with the first circuit gaduatiojn on the wiper strip.
If all is well...the VOM should not have started beeping that you have made connection.
Tighten one locking screw.
Now open and close the throttle plate.
What you visually should see....is two things.
(1) The wiper arm contact....as noted should be about .005" short of making contact with the first "loop" of the series on the printed circuit
and
(2)When looking at the little pair of parralell "whisker" contacts in the top of the arm...the rearward whisker should be touching its post. The forward one...should be about .005" from touching its post.
What this does....is when the throttle is cracked more than 1*...the wiper arm makes contact with the first loop of the circuit series...at the same time the forward leg of the parrallel whisker switch makes contact with the forward post. This makes for a very sensitive switch.
The object is also.....that when the throttle plate is in forward motion (opening)...the forward leg of the upper pair of parrallell whiskers switches is ALWAYS in contact with the forward post.....while in motion. In theis way...whenever the throttle is being opened....it is transmitting the contact of teh wiper arm below across the circuit loops. When the throttle stops moving toward open and is stationary with the throttle open....OR...when the throttle plate is moving in reverse...towards closed....the rearward leg of the upper parralell whisker switch is in contact with the rearward post....which breaks contact for the lower wiper contacts....and in the middle years....having the rearward leg on the rearward post.....also activates the overrun cut-off system. Ray
I think I have a post on this already.
(1)Remove the TB from the plenum.
(2) Hold the TB in your left hand...with the outside side (air filter side)...facing your right.
(3) hold it upside down with the TPS facing you....black cap off.
(4) Loosen...just barely, the locking screws.
(5) with your left hand, grip the TB...with two fingers, or your thumb pushed inside from the plenum side...to hold the plate tightly closed.
Now...this is going strictly from memory...so check the connector numbers. But...you need to connect a VOM onto connectors 17 and 22....I think. Set it on continuity. We are just checking for connection. Resistance...unless it is just extremely high...is NOT a factor on the D-jet TPS. The D-jet TPS is simply a series of on/off switches.
Now...rotate the TPS body toward closed. That means....that as you look at the guts of the TPS...the wiper arms are down near one end of the curved circuit. You want to rotate the plate until the wiper drops off the very last one. On some models..you may even see a little square "parking" area etched into the circuit for the contact tip....at least this is what I call it. I am having you do this just so you know the complete range.
This causes the little pair of floating "whisker" switches that contact the two brass posts...up in the top of the arm...to be overly closed.
Now...rotate the plate....still keeping the throttle plate tightly closed....in the opposite direction....until the tip of the wiper arm is just paused like about .005" before making contact with the first circuit gaduatiojn on the wiper strip.
If all is well...the VOM should not have started beeping that you have made connection.
Tighten one locking screw.
Now open and close the throttle plate.
What you visually should see....is two things.
(1) The wiper arm contact....as noted should be about .005" short of making contact with the first "loop" of the series on the printed circuit
and
(2)When looking at the little pair of parralell "whisker" contacts in the top of the arm...the rearward whisker should be touching its post. The forward one...should be about .005" from touching its post.
What this does....is when the throttle is cracked more than 1*...the wiper arm makes contact with the first loop of the circuit series...at the same time the forward leg of the parrallel whisker switch makes contact with the forward post. This makes for a very sensitive switch.
The object is also.....that when the throttle plate is in forward motion (opening)...the forward leg of the upper pair of parrallell whiskers switches is ALWAYS in contact with the forward post.....while in motion. In theis way...whenever the throttle is being opened....it is transmitting the contact of teh wiper arm below across the circuit loops. When the throttle stops moving toward open and is stationary with the throttle open....OR...when the throttle plate is moving in reverse...towards closed....the rearward leg of the upper parralell whisker switch is in contact with the rearward post....which breaks contact for the lower wiper contacts....and in the middle years....having the rearward leg on the rearward post.....also activates the overrun cut-off system. Ray