15 vacuum regulator adjustment for c4
DESCRIPTION
How to adjust shift points and shift feel by adjusting modulator. Late shifting harsh shifting.TRANSCRIPT
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A ,
7
I Ford RWD
a&nk I c6wmieseAd]ustmg VacuumDate: 04/24/92
Regulator VaIveFile: C6
The Va~uim Regulator Valve Is Very Important OnDiesel Engines And Needs To Be Adjusted Properly
By Joe Cangelosi, Tech Hotline RepThere is no Manifold Vacuum ondiesels t
Diesel engines do not have manifoldvacuum. Because of this, there has tobe a vacuum source and a way of vary-ing vacumm to the transmission. Avacuum pump is that vacuum sourceand the Vacuum Regulator Valve (VRV)is used to control the vacuum signal tothe transmission so that it can operateas it does on gas engines. The VRV islocated on the fuel injection pump andis operated by the throttle lever.
What to do if you have a C6/Dieselwith shifting problems
If you have a Ford truck with a dieselengine and shifting problems like noshifts, early shifts, late shifts, or erraticshifts, the problems could be caused bypoor vacuum response. The VRV orvacuum pump could be the problem.The first thing to check is the vacuumpump. With the engine running, makesure you have at least 20 inches ofvacuum available from the vacuumpump. H you do, proper adjustment ofthe VRV is next. If not, check or replacethe vacuum pump.
VaPI II am -1- Vacuum To Transmission.-, !
supply
Vacuum RegulatorValve (VRV)
If TW%
FuelInjection
L/ Ump
)Ford VRV and Fuel Injection Pump
Step-By-Step Adjustment of theVRv
To check the VRV for proper opera-tion and to adjust it, the engine mustNOT be running.
1. Disconnect the two port vacuumhoses from the VRV located on the leftside of the fuel injection pump.
2. Attach a hand vacuum pump to theupper port of the VRV (vacuum supplyside). If you do not have a vacuumpump use an air conditioner vacuumpump or run a vacuum hose from arunning gas engine to the upper port.
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3. Attach a vacuum gauge to thelower port of the VRV, which is labeledTRANS.
4. Apply 20 inches of vacuum to theVRV if using a hand pump. It will benecessary to pump the vacuum upduring the test as it bleeds off.
5. Cycle the throttle lever 5 timesfrom idle to wide open throttle withvacuum applied.
6. Insert a .515 gauge block (FordPart# T83T-7B200-AH) or a 1 /2 blockof wood between the pump boss andthe wide open throttle stop. Make sureyou hold the throttle lever against theblock. The vacuum gauge attached tothe lower port should read between 6and 8 inches of vacuum. If reading isnot correct, adjust the VRV to get areading of 7 inches of vacuum.
7. To adjust, loosen the two adjustingscrews and rotate the valve until youget 7 inches of vacuum.
8. Remove the gauge block and applyand maintain 20 inches of vacuum tothe top port of the VRV.
9. Cycle the throttle lever 5 timesfrom idle to wide open throttle. Checkthe vacuum at the lower port with thethrottle at the idle position. It shouldbeat least 13 inches of vacuum. If theVRV cannot be adjusted to get the
THROITLF LOWER PORTWIDE43PEN (TRANS.) UPPER PORTSTOP (NON-
I(SUPPLY SIDEI
ADJUSTABLE) /
////
T83T-782004iH
\FRONT OF ENGINE
THRO-TTLER ET U R NSPRING
pU~P BOSS
wide open throttle stop . .
Proper vacuum readiruz or fails anv~ar; of this test, it mus;be replaced andthe new VRV adjusted with the stepslisted above.
10. Remove your vacuum source andvacuum gauge, then re-connect thevacuum hoses making sure they are onthe right port. Check throttle opera-tion, and check vacuum at the modula-tor. If the vacuum and vacuum re-sponse is not exactly the same at themodulator as it was from the VRV, lookfor a leak, kink, or collapse in thevacuum line to the modulator.
OlSS2 AAMCO Trmarnhbns, Inc. All Rights Reserved. Primed in U.S.A.