'73 914 1.7 W/d-JET after a long 6-8mo.
sit is now alive in my '67 Porsche 912!
It idles and runs smooth with no obvious
evil noises, but is pumping out some very
stinky exhaust<G>
The engine has a California History..
bought from running car in a quick trade,
but zero history.
Is rich black smoke residual California
gas being bruned off, or is this strong
black smoke indicateing rich mixture with
the D-jet or some critical yet un-connected part?
WWUDO?
Doc
after a long sit my 1.7 blows black smoke
- Dave_Darling
- Posts: 2534
- Joined: Thu Apr 27, 2000 12:01 am
after a long sit my 1.7 blows black smoke
Probably a filthy-stinking-rich mixture.
Step 1: Check the ignition system thoroughly. All of it.
Step 2: Valve adjust and compression check.
Step 3: Verify hose condition and routing. Make sure the wires are all plugged in correctly. Check fuel pressure--should be 29 PSI.
Step 4: Verify part number for the MPS. (I once tried a Type III MPS that caused my 914 to blow black smoke.)
Step 5: Check condition of FI parts. In particular, the MPS may not hold a vacuum. Or the head temp sensor may have very high resistance. Or there could be some other cause.
--DD
------------------
1974 VW-Porsche 914 2.0 (Type IV powered!)
Pelican Parts' 914 Tech Geek http://www.pelicanparts.com
Step 1: Check the ignition system thoroughly. All of it.
Step 2: Valve adjust and compression check.
Step 3: Verify hose condition and routing. Make sure the wires are all plugged in correctly. Check fuel pressure--should be 29 PSI.
Step 4: Verify part number for the MPS. (I once tried a Type III MPS that caused my 914 to blow black smoke.)
Step 5: Check condition of FI parts. In particular, the MPS may not hold a vacuum. Or the head temp sensor may have very high resistance. Or there could be some other cause.
--DD
------------------
1974 VW-Porsche 914 2.0 (Type IV powered!)
Pelican Parts' 914 Tech Geek http://www.pelicanparts.com
-
- Posts: 21
- Joined: Mon Jan 21, 2002 12:01 am
after a long sit my 1.7 blows black smoke
Dave,
First off what is a "MPS"?
Second, could you elaborate on how to check the head sensor??
My 1.7 appears to be running a little rich also, idles high at lowest idle setting, black exhaust pipe, etc...
First off what is a "MPS"?
Second, could you elaborate on how to check the head sensor??
My 1.7 appears to be running a little rich also, idles high at lowest idle setting, black exhaust pipe, etc...
- Dave_Darling
- Posts: 2534
- Joined: Thu Apr 27, 2000 12:01 am
after a long sit my 1.7 blows black smoke
As we discussed in our earlier e-mail, the MPS is the Manifold Pressure Sensor.
Two really great D-jet resources--
http://www.914fan.net/djet.html
http://members.rennlist.com/pbanders
--DD
------------------
1974 VW-Porsche 914 2.0 (Type IV powered!)
Pelican Parts' 914 Tech Geek http://www.pelicanparts.com
Two really great D-jet resources--
http://www.914fan.net/djet.html
http://members.rennlist.com/pbanders
--DD
------------------
1974 VW-Porsche 914 2.0 (Type IV powered!)
Pelican Parts' 914 Tech Geek http://www.pelicanparts.com
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- Posts: 1941
- Joined: Thu Jul 19, 2001 12:01 am
after a long sit my 1.7 blows black smoke
If you are idleing too high at lowest screw position...you have a vacume leak. Most probably a hose, injector seals or manifold boots...and very probably the diaphram in the back of the MPS could be cracked. This will cause black smoke most noticably on start-up...and an over rich condition, because loss of vacume in the MPS signals enrichment at the diaphram. Ray
- Piledriver
- Moderator
- Posts: 22518
- Joined: Sat Feb 16, 2002 12:01 am
after a long sit my 1.7 blows black smoke
Propane torch (unlit) is a safe way to find vacuum leaks, the biggest cause of rich running on that EFI system.
-
- Posts: 57
- Joined: Fri Oct 19, 2001 1:01 am
after a long sit my 1.7 blows black smoke
*BINGO!
*Problem solved!!
MPS line was burned off and
there was other vacume issues!
Runs great!
Thanks!
Doc
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Piledriver:
Propane torch (unlit) is a safe way to find vacuum leaks, the biggest cause of rich running on that EFI system.<HR></BLOCKQUOTE>
*Problem solved!!
MPS line was burned off and
there was other vacume issues!
Runs great!
Thanks!
Doc
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Piledriver:
Propane torch (unlit) is a safe way to find vacuum leaks, the biggest cause of rich running on that EFI system.<HR></BLOCKQUOTE>
-
- Posts: 1941
- Joined: Thu Jul 19, 2001 12:01 am
after a long sit my 1.7 blows black smoke
Burned off?...I thought piledriver said to use an unlit torch! Hee Hee Ray