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Hi guys, Im new to the forum and have tried to read as many posts as I can find on the particular symptoms I am experiencing and I have found a few threads already with some useful suggestions however my only problem is that all of the threads that I have read refer to the GA16 engine.
I have a 98 Sentra with a 1400cc (GA 14) engine which was running fine up until I had the engine cleaned with a high pressure water sprayer.
Since then I have experienced the following symptoms:-
At normal operating temp - Erratic idle speed (between 500rpm above or 200rpm below normal idle speed) At low engine speeds and small to medium throttle openings (such as when pulling off) the engine will baulk or surge. Once the car is up to normal cruising speed and the torque requirements on the engine are low, the engine will run smoothly again. The engine is generally down on power and the fuel comsumption is up to maggots. When the throttle is completely closed and the car is coasting up to a stop, it also starts to become jerky at lower speeds.
The engine management light has not illuminated once yet during these symptoms.

The things that I have already checked:-
1) The distributor cap, rotor, timing and plug leads and all seem healthy, the plugs were rather sooty (rich) so they got a clean and regap but they were otherwise quite OK.
2) The compression pressure, with each cylinder recording just short of 17 bars, there was minimal variation between cylinders.
3) I have checked for vacuum leaks by using the usual trick of spraying flammable deodorant around all manifold joint / gasket areas and around the injector seals with the engine idling, there was no increase in idle speed, so I dont suspect a leak.
4) I have removed the throttle body, given it a good cleanup and reset the fast idle cam to spec. I have not tested the MAS or TPS sensor as I do not know what the testing procedure is (help anyone). There are also two solenoids that screw into some kind of air bypass system on the throttle body which I have also not tested as I am not quite sure how they function / what they are supposed to do (another help anyone).

So, I have now drawn a blank, I am pretty sure that mechanically, the engine is fine, I dont think that there is any residual water in the electrics since the engine cleaning because it has been a month now since the engine was cleaned and any water would have dried up / evaporated by now, however the symptoms definately seem to be related to the engine cleaning episode.

From the other posts I have read, a common suggestion as cause for the problem is either the MAS or TPS, but does anyone have a testing procedure for these sensors on the GA14 engine.
Anybody got any other good problem shooting tips or had similar problems and found the cause? Any and all suggestions will be appreciated.
 
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