Vtec 16 valve engines. ford. Ihave worked on several of these .I would like some info on the vibration problem these seem to have. ie... valves, out of time,(timing belt?) Balanced torque converter. I am a mechanic and know quite abit about engines and trannies. This one has me stumped at the moment and I would like to get ifo befare I tear it all aprt and find out for myself..

Here is the explanation from engine-codes.com

P1259 Honda Description
The VTEC system activates the VTEC solenoid valve by command from the powertrain control module (PCM), and it charges/discharges the hydraulic circuit of the VTEC mechanism that is installed in the valve system to switch valve timing between Low and High. The PCM monitors oil pressure conditions in the hydraulic circuit of the VTEC mechanism according to the VTEC oil pressure switch downstream of the VTEC solenoid valve. If there is a disparity between oil pressure condition in the hydraulic circuit that is determined by the PCM command, and the oil pressure condition that is determined by the status of the VTEC oil pressure switch, the system is considered faulty and a DTC is stored.

Read more: http://engine-codes.com/p1259_honda.html#ixzz3aiInXy9j

read only the honda books on P2xxx codes, its unique to honda.
VVT, variable valve timing (cam) magic is unhappy

P2649 Honda - VTEC Solenoid Valve Circuit High Voltage


Possible causes
- Check engine oil level and pressure
- Faulty VTEC Solenoid Valve
- VTEC Solenoid Valve harness is open or shorted
- VTEC Solenoid Valve circuit poor electrical connection

http://engine-codes.com/p2649_honda.html

(As in the Honda VTEC engines.) VTEC = (Variable Valve Timing and Lift Electronic Control)
In a VVT equiped engine the valve timing (How long an intake or exhaust valve is open or closed) is controled by this solenoid. As in the Honda VTEC engines there is an extra intake cam with its own rocker, which follows this cam. The profile on this cam keeps the intake valve open longer than the other cam profile. At low engine speeds, this rocker is not connected to any valves. At high engine speeds, a piston locks the extra rocker to the two rockers that control the two intake valves.

P 1259 VTEC oil pressure switch circuit or vtec solenoid or valve,Here the situation you can be dealing with the oil pressure switch or the VTEC solenoid or valve,

A rubber cover.

You need a shop manual to get the proper timing info. Basically, you are timing the camshaft with the crankshaft so the valves open & close at the proper time. If you are off, the engine will run poorly and you might even cause the valves to hit the pistons and cause severe engine damage.

is it a vtec if so check oil level as if gets low causes problems with the variable valve timing due to low oil pressure which causes poor performance and brings on mil light.

it sounds like your valve cover is bent, you may need to buy a new one, did you use any gasket sealer with the cork gsket? if not remove the valve cover and use gasket sealer..... Apply it driectly to the cork gasket...... if you did not use sealeant this is why it is leaking.

Please rate me solved...thanks!
DTC P1259: VTEC SYSTEM MALFUNCTION
1. Perform PCM reset procedure. See SELF-DIAGNOSTICS - INTRODUCTION article. Start engine
and run at 3000 RPM with no loads and transmission in Park or Neutral until radiator fan comes on. Road
test vehicle. Accelerate in 1st gear to an engine speed over 4000 RPM and hold that engine speed for at
least 2 seconds. If DTC P1259 is not indicated during first road test, repeat road test 2 more times. If DTC
P1259 is indicated, go to next step. If DTC P1259 is not indicated, problem is intermittent. System is
okay at this time. Check for poor connections or loose wires at VTEC solenoid valve connector and PCM.
See ENGINE PERFORMANCE WIRING DIAGRAMS article. Repair as necessary.
2. Turn ignition off. Disconnect VTEC pressure switch 2-pin connector. Check for continuity between
VTEC pressure switch terminals. If continuity exists, go to next step. If continuity does not exist, replace
VTEC pressure switch.
3. Turn ignition on. Measure voltage between ground and VTEC pressure switch harness connector terminal
No. 2 (Blue/Black wire). If about 12 volts exist, go to next step. If about 12 volts do not exist, check for
an open or short in Blue/Black wire between VTEC pressure switch and PCM 31-pin connector "C"
terminal No. 10. Repair as necessary. If wire is okay, substitute a known-good PCM and recheck. See
SUBSTITUTING PCM in SELF-DIAGNOSTICS - INTRODUCTION article. If symptom or problem
goes away, replace original PCM.
4. Measure voltage between VTEC pressure switch harness connector terminals. If battery voltage exists, go
to next step. If battery voltage does not exist, repair open in Brown/Black wire between VTEC pressure
switch and ground connector located on left side of engine, under throttle plate, between end of radiator
hose and cooling fan switch. See ENGINE PERFORMANCE WIRING DIAGRAMS article. If wire is
okay , substitute a known-good PCM and recheck. See SUBSTITUTING PCM in SELFDIAGNOSTICS
- INTRODUCTION article. If symptom or problem goes away, replace original PCM.
5. Turn ignition off. Disconnect VTEC solenoid valve connector. Measure resistance between ground and
VTEC solenoid valve connector. See ENGINE PERFORMANCE WIRING DIAGRAMS article. If
resistance is 14-30 ohms, go to next step. If resistance is not 14-30 ohms, replace VTEC solenoid valve.
6. Remove VTEC pressure switch and install Pressure Gauge Adaptor (07NAJ-P07010A) and A/T Low
Pressure Gauge (07406-0070300). Reinstall VTEC pressure switch into adaptor. Connect tachometer.
Start engine and with no loads and transmission in Park or Neutral until radiator fan comes on. Because
engine is running with no load, oil pressure must be checked within one minute. Check oil pressure at
engine speeds of 1000, 2000 and 3000 RPM. If oil pressure is less than 7 psi (48 kPa), go to next step. If
oil pressure is 7 psi (48 kPa) or more, check VTEC solenoid valve. See SYSTEM & COMPONENT
TESTING article.
7. Turn ignition off. Disconnect VTEC solenoid valve connector. Connect a fused jumper wire between
battery voltage and VTEC solenoid valve connector. Start engine and check oil pressure at 3000 RPM. If
oil pressure is more than 57 psi (393 kPa), go to next step. If oil pressure is 57 psi (393 kPa) or less,
check VTEC solenoid valve. See SYSTEM & COMPONENT TESTING article.
8. Ensure jumper wire is still connected to VTEC solenoid valve connector. Start engine and allow it to idle.
Set engine speed to more than 4000 RPM and measure voltage between ground and PCM 31-pin
connector "C" terminal No. 10 (Blue/Black wire). See ENGINE PERFORMANCE WIRING
DIAGRAMS article. If battery voltage exists, go to next step. If battery voltage does not exist, replace
VTEC pressure switch.
9. Turn ignition off and disconnect jumper wire. Check for continuity between VTEC solenoid valve
harness connector and PCM 25-pin connector "B" terminal No. 12 (Green/Yellow wire). See Fig. 2 . See
ENGINE PERFORMANCE WIRING DIAGRAMS article. If continuity exists, go to next step. If
continuity does not exist, repair open in Green/Yellow wire between VTEC solenoid valve connector and
PCM 25-pin connector "B" terminal No. 12.
10. Check for continuity between ground and VTEC solenoid valve connector. See ENGINE
PERFORMANCE WIRING DIAGRAMS article. If continuity exists, repair short in Green/Yellow
wire between VTEC solenoid valve connector and PCM 25-pin connector "B" terminal No. 12. If
continuity does not exist, substitute a known-good PCM and recheck. See SUBSTITUTING PCM in
SELF-DIAGNOSTICS - INTRODUCTION article. If symptom or problem goes away, replace original
PCM