hard start/rough idle

[buckinbroncII]

My 1988 Bronco II EB edition 2.9 V6 was running great, coming home in the rain I hit a puddle big enough to almost hydroplane, right after the truck started running like it was on 3 or 4 cylinders. I did the usual for older cars thinking it was the distributor got wet, cleaned distributor cap but same results. Hard to start, won`t idle and fuel fouls the plugs. So I changed the plugs, changed the ignition control module and no change.....raw fuel comes out the exhaust when I try to run it....any ideas?

 

[RonD]

Welcome to TRS

OK lets look at fuel first

On the upper engine passenger side front is the Fuel Pressure Regulator(FPR), it will have the Fuel Return line attached to it, and a Vacuum Line
Remove vacuum line and check it for gasoline, if FPR leaks raw fuel will get sucked into the engine.

The fuel injectors all get 12volts when key is on, the computer Grounds the injectors to open them and add fuel.
There will be 1 Red wire on each injector, it is daisy chained from one injector to the next, thats the 12volt wire.
On an '88 the computer will use Batch fire injection, on a V6 that mean there will only be two ground wires back to the computer, so computer opens 3 injectors at the same time, then opens the other 3 the next time.
Should be a Light green wire and a Tan wire as the two ground wires, each going to 3 injectors.
IF......big if, one of these ground wires was shorted to ground by the water spray then those 3 injectors would open with Key ON
You could use a volt meter connected to Battery + and then test both Ground wires with key off, shouldn't be Grounded, so 0 volts

On the fire wall toward center on passenger side is the MAP sensor, this is the main air/fuel mix sensor used by the computer
It will have a 3 wire connector and a vacuum line
Make sure connector is clean and dry inside and test vacuum line, make sure it holds vacuum, no cracks and is hooked to intake manifold

 

[buckinbroncII]

RonD,
thanks for the new direction, I`m a carb guy so the fuel injection is a nightmare for me. My thoughts were centered on old school water in the distributor stuff so now I have a great way to deal with troubleshooting this from the fuel injection deal. Thank you again, I`ll update my progress once I get time to get under the hood.

 

[buckinbroncII]

RonD, I finally got a chance to get under the hood and there was some crud in the distributor cap but the fuel pressure regulator was the bigger culprit....THANK YOU for giving a lost guy some direction. I pulled the vacuum line to the regulator and surprise I had gas...Thanks again, I couldn't have taken what the garage was going to do to me to fix it.

 

[RonD]

Good work

Thanks for posting the FIX, should help others down the road

 

[wildbill23c]

Check your air filter too, if you hit a puddle large enough to get water into the distributor you may have some water in your air filter & air box.