HELP water in gas

[Earl43P]

I recommend that you mist the spark plug wires with water while the engine is idling, looking all over for any arcing, especially at the boots for the plugs. Once they are wet, rev it at the throttle body watching for arcs again.

Are you correlating your problem to rainy weather?

 

[mrln1955]

I recommend that you mist the spark plug wires with water while the engine is idling, looking all over for any arcing, especially at the boots for the plugs. Once they are wet, rev it at the throttle body watching for arcs again.

Are you correlating your problem to rainy weather?

I believe that the humidity associated with rain contributed to the problem, but was not directly correlated. In December we had more days with freezing fog than rain. Stumbling would occur with a dry engine compartment and warmed-up engine. Since I added the HEET and changed the filter I have driven about 50 miles. The stumbling behavior ceased after about 30 miles, with the last 20 or so miles driven without incident. This behavior is similar to what happened last year, but this time I was running an ODB scan using ODBCOM connected to a laptop for much of the time. There were never any stored or pending codes, and no freeze frame data produced during periods of stumbling.

Am I correct in assuming that the misfire monitoring function of the PCM would produce a DTC if a significant amount of arcing were taking place? Since the OBD had no DTCs and the engine could idle smoothly for relatively long periods and only stumble when the accelerator was depressed, I'm convinced that the problem is/was in the fuel. It appears that the fuel filter change and HEET have cleared the problem. Looking forward, I am going to have to keep more fuel in the tank and drive more often. Thanks for your help.

mrln1955

 

[mrln1955]

I'm convinced that the problem is/was in the fuel. It appears that the fuel filter change and HEET have cleared the problem.

mrln1955

Well, I was wrong. The problem has not gone away. I can idle smoothly for long periods in neutral (> 5 minutes) during which the RPM will drop with a very light touch on the accelerator but rise back to normal if the pedal is released. Anything more than a light foot will stall the engine. Eventually, the engine will rev up instead of down when the accelerator is pressed. This can happen when the engine is cold or warmed up. On occasion I can drive for 20 miles with normal power at freeway speeds before the problem returns. Yesterday I crawled up the hill to home in first gear while idling since the engine would die if I depressed the accelerator.

I've changed the fuel filter twice, added HEET, and the fuel pressure is 62psi (key on, engine off) and 66psi engine running. During the second fuel filter change I drew a 1.2 liter fuel sample that showed no sediment, cloudiness, or water.

I still have not seen any codes or freeze frame data. I've read that the EGR valve or coil pack can cause problems without throwing a code. Does anybody have any suggestions as to what component could be failing and/or what real time data I should look at?

 

[Earl43P]

You can rule out EGR by simply removing the vacuum line that actuates the EGR valve, plug the open line. You can drive it like that for quite a while until the CEL will light.

62 psi engine off sounds good....66 psi engine running DOESN'T. What does fuel pressure do when you punch the throttle to a high rpm? It should INCREASE. Gotta know that the fuel pressure regulator is working and it sounds like your is at WOT (max fuel pressure) and shouldn't be. Does the exhaust smell pig-rich (gassy)?

Unless I'm mistaken, your FPR is part of the fuel pump in the tank assembly. Might need to get creative and pinch a line to the tank....while monitoring psi. I need to think up a cheat for that type FPR.....maybe a certified smart guy will jump in with that...

Is there a vacuum line to the top of the tank? Not to be confused with the vacuum line to the Evap Emissions tank by the spare tire.

 

[mrln1955]

Hi Earl43P,

Thanks for the response. after reading your post (and RTFM) I am going to get a vacuum pump/tester so that I can get some vacuum readings to correlate with the fuel pressure. I had not realized that the fuel pressure should drop (3-10psi per Chilton) when the engine is started.

mrln1955

 

[mrln1955]

Unless I'm mistaken, your FPR is part of the fuel pump in the tank assembly. Might need to get creative and pinch a line to the tank....while monitoring psi. I need to think up a cheat for that type FPR.....maybe a certified smart guy will jump in with that...

Is there a vacuum line to the top of the tank? Not to be confused with the vacuum line to the Evap Emissions tank by the spare tire.

Hi Earl43P,

I can locate the two fuel lines and an evaporative system line running to the fuel tank, but I can't find a straight vacuum line. The vacuum routing diagram on the chassis only shows an evap line running from the VMV to the fuel tank. At the canister, I can only find one line running to the fuel tank. From what I have read, there is supposed to be a vacuum line running to the fuel pressure regulator, and the fuel pressure regulator is supposed to be part of the fuel pump assembly that resides in the fuel tank. However, when I look at online images of the fuel pump assembly for a 2.5L 4cyl. 2000 Ford Ranger, I am hard pressed to find something that resembles a vacuum port for the fuel pressure regulator. Is it possible that the line running from the VMV is the "vacuum line" referred to in the manuals?

mrln1955