98 3.8L Hard starting when hot

[12Ounce]

In both cases, I would suspect an underperforming fuel pump.

[bkimbel]

I did have a fuel pump that failed and was replaced with a standard one from Ford about a year or so ago.

My mechanic was checking on the bleed down suggestion and said the fuel pressure was correct after the 15-20 wait time.

If the pump was underperforming, wouldn't present some problems at wide open throttle, too?

[12Ounce]

Good point!

[perrytime]

I don't mind sharing my solution, but haven't documented anything and it has been a couple years. I did the replace fuel pressure regulator, no help. Before replacing it, I put on a pressure gauge and the pressures were in spec(pre and post start) and the same when the rough idle happened as when it didn't. once a new IAC definetelly seemed to help for a few months, then issue came back, I returned the autozone brand and put on a Motorcraft part, didn't fix it. Just to be clear, it was not a hard start issue, but a rough idle after starting. I would suggest you verify pulling vacuum from FPR will in fact solve your issue. If so , i will work on documenting what i did.

[bkimbel]

Now at 286,000 miles.

So now I'm back to warmer weather, and the hard start when hot and the bobbles under load have returned.

I've just re-read this thread, and will check the camshaft and crank sensors for crud.

Any other ideas?

[SleepyHead98]

Are you getting a Camshaft /Crank position code? If so, then you replaced them and are still getting them? Then its the timing chain.

[12Ounce]

How about on the ignitions side of things. How old are the spark cables, the ignition coil and the plugs? Might be time to replace them all at once.

[bkimbel]

Ignition coil, plugs and wires all new within the last year.

No Camshaft or Crank position codes.

[12Ounce]

I wonder if you are getting vaporization of fuel in the line between the pump and engine. Bubbles in the line. Caused primarily by hot spots along the fuel line, but worsened by a leaky check valve in the fuel pump.

??

Have you tried cycling the pump on several times before restarting the hot engine? Won't stop it, but might change it a bit....

[bkimbel]

This may be too simple of a solution...

My 98 3.8L Windstar has been suffering from the hot soak, warm soak, hard starting when hot problem for quite some time now.

The Windstar is now at 288+ miles.

In the last couple of months, Florida started allowing gas dealers to sell Ethanol Free gas. I found a local BP dealer offering the E-0 "pure gas", and bought some for my lawn mower, and while there, topped off the tank with a couple of gallons.

A week later, I added about 10 gallons to fill up the tank, then went on a 450 mile road trip. On the way back, as I was closing in on 1/4 tank, I found a station offering E-0 (using the Pure Gas application in my iPhone).

Since I added the E-0, and particularly since I flushed out most of the Ethanol, I have not had a single warm soak missing problem.

I plan to run one more tank of E-0 through, then if I am still not having a problem, I will refuel with my normal Costco or Sam's gas and see if the hard starting returns.

FYI - the 87 octane is close to premium gas prices, but Georgia's prices are better!

[mdare35]

When my van started running rough and had a P0302 code I switched plug wires 2 and 6 and the code didn't change banks so I put a new fuel injector into cylinder 2 and that fixed my problem.

[ajb0009]

I have had this same issue on my 98 with 140k miles. Like the guy from FL said, I have been using E-0 pure gasoline (89 octane) for a while now and have not had the problem since. If that does not work, I found another post a year or so ago where someone with a posting name of "tkswa" tried everything under the sun to fix the problem, and finally the dealer found a TSB where the reprogrammed the PCM and that took care of it. He actually said that his van run better that it ever did after he had that done. He could not come up with the TSB number though.

[tomj76]

I've had these same problems for a long time. Here's a couple of observations that I'd like to share:

1) The Hot start problem seems to require at least 10 minutes of the hot car sitting before attempting restart. Otherwise it will start and run fine.

2) When you restart and experience misfire, a "gurgling" sound can be hear from the gas tank, if you turn off the radio and get all the kids to remain quiet.

3) If you cycle the ignition key from "OFF" to "ON" then back to "OFF", each time waiting for the pump to reset, and repeat this until the gurgling noises stop, the engine will run fine on restart.

Regarding the bobble/surge, I have characterized this a "chatter" before, but I think in my case it is slightly different because of a transmission issue that I have.

1) Depending on conditions, while crusing at 60-70 mph (constant speed), with the A/C on, there is a regular interval for the "bobble". With the scan tool attached, you can observe the RPMs increase, stabilize, then decrease. I believe this is because the torque converter clutch was disengaged, then re-engaged by the PCM.

2) If the A/C is off, then this rarely happens.

3) If your transmission is chattering when the TCC engages, then you'll feel a shutter in the steering wheel. No cylinder has misfired, but the clutch "bounced" during the engagement.

4) It doesn't seem to matter if you are traveling up or down a slight grade.

I don't know how to cure either of these problems, and I find your experience with the IAC interesting. I don't quite understand how the IAC can affect a symptom that only occurs when the throttle is open. Any insight?