1991 Honda Prelude engine warning light comes on and S4 flashes.

Sounds like a fuel delivery problem. Have you checked fuel pressure with a gauge?

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3s, humm...... what is that, google shows ZERO for that.
can i know what object shows that? dash, ECU, trans shift.? what?
where are your eyes looking,?
is this the ECU flash code>? LED? at ECU?

"1985-91 Prelude models, there is only one LED display."
ECU code 3 is bad MAP (or bad vacuum to it)

Carb engine or EFI engine./ and which engine?> "options"

here is the FSM , look it up , gen 2 to 5
http://hondatech.info/downloads/Auto/Manuals/Prelude/

Have the code checked. When the check engine light is on you car is warning you of a problem.
Try your local auto parts store and have them pull the

Best would be to check the oil pump filter in the sump of the engine. these also clog up and drops the oil pressure resulting in a warning light

No. 1 CYLINDER POSITION (CYL SENSOR)

Try another known good distributor. The signal comes from inside the distributor.

change the shift solenoid and it will help ,if this doesn't then change the main relay.

UNDER THE GLOVEBOX INSIDE THE PASSENGER KICKPLATE NEAR THE FLOOR IS A TWO WIRE CONNECTOR BEHIND THE PANEL. JUMP THIS CONNECTOR WITH A PAPER-CLIP AND TURN THE IGNITION SWITCH ON AND WATCH THE CHECK ENGINE LIGHT TO COUNT THE FLASHES. ONE LONG FLASH AND THREE SHORT ONES INDICATES A CODE OF 13. IF THERE IS MORE THAN ONE CODE THEN IT WILL FOLLOW THE FIRST CODE. THIS WILL SOLVE YOUR TROUBLES I AM SURE. LET ME KNOW. GOOD LUCK. P.S. IF YOU WANT TO ERASE THE CODE(S) THEN DISCONNECT THE NEGATIVE BATTERY TERMINAL FOR 10 SECONDS. BUT YOU'LL HAVE TO RESET THE CLOCK AND PRESETS.

Not exactly sure, but I believe is the ignition indide the distrubitor. It's out of timing.

If your check engine light is on then it means that there are codes stored in the computer. The easiest way to find out what they are is to go to an Advance Auto Parts Store or Autozone as I know they will read the codes and tell you what they are for free. If you do not have one of those stores around you I would suggest finding any auto parts store that offers a free diagnostic check. Once you know the code then you will be able to fix the problem. I am not sure why the S1 light is coming on but I do know that the first step to fixing your problem will be to get the codes read. otherwise you will just keep guessing. Hope this helps.

I believe this is a warning of a transmission problem (flashing S4 light), and u should have it checked by a good trans. shop or dealer. When The engine light comes on and stays on,(does it only go on when the S4 light flashes?)it is a warning of a problem (fuel injection/emissions system), which u can check by doing the following: There is a Electronic Control Unit (ECU), located under the carpet on the passenger (front) side near where your feet would be. There is an LED display on the ECU, the display is a small circle, I believe located at the top center of the ECU. When u get the ECU exposed(by pulling back the carpet), turn the key on, and observe the LED. If any codes were stored regarding a problem, the LED will flash. Count the flashes, Codes 1 thru 9 are a series of short flashes, two digit codes use a long flash for the 1st digit, and a short flash for the 2nd digit. Codes are separted by a pause between displays. If u have multiple codes , they are transmitted in a alternating pattern. Time and space make it hassle to list all codes ( there are 19 for the 91 Prelude), so if u want to go ahead and check the codes, let me know what they are , and I'll tell u what they mean. Good Luck! countrycurt0