Mechanics

ENGINE STALLS AT IDLE

1999 Ford Windstar

Engine Performance problem
1999 Ford Windstar 6 cyl Front Wheel Drive Automatic 131000 miles

My Windstar dies at idle when at operating temp. It's worse when in gear, but still does it in neutral. I've replaced: fuel pump, fuel filter, egr valve, MAF, IAC, spark plugs, coil pack. I've cleaned the egr ports in the intake. Sealed the bolts holding the plastic intake to the aluminum intake. Sealed the top plastic intake to the bottom plastic.

It still dies, and it seems to be getting worse. It would start right up after dying, now it's getting harder to start when it dies. It's not hard to start warm if shut down normally.

Help. Thank You
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BCAnderson
August 27, 2009.



Is the engine light on? If so call around to your local parts store, and find one that will do a free scan and get it scanned write down the codes, and have them clear the codes after done. Get back to me with any codes and we will take it from there.

Racefan966
Aug 27, 2009.
No, I forgot to mention, no engine lights, no Codes. I have a simple code reader.

Tiny
BCAnderson
Aug 27, 2009.
Does the engine slowly sputter to a stop, or is the stalling immediate? I ask this because I'm trying to help you isolate if it's a fuel/mechanical issue, or an electrical issue.

If the engine slowly sputters to a stop, it's likely fuel related, or an actuator which is operating when it's not supposed to. For example, something might be commanding the EGR to open while at idle (it's not supposed to). Thus, the engine will sputter and stall slowly. Try somehow disconnecting the EGR vacuum hose (plug it on the vacuum side) so that the EGR is effectively disabled.

Conversely, if it dies immediately, it's likely electrical related.

Other words of advice, take electrical voltage measurements at the battery terminals while the stalling is occurring. Take measurements directly at the LEAD battery posts (+ / - ), and also place the voltmeter test leads directly on the METAL battery terminals ( + / - ). By doing this, you are verifying continuity between the lead and metal contacts. Follow the wire (ground) all the way to the engine block; make sure connections are clean and tight.

Also, place one voltmeter test lead on the LEAD battery post ( + ), and one test lead on any of the maxi fuses in the fusebox. The voltmeter must read zero. Crank the engine and see if you have any reading on the voltmeter. You'll need to experiment with different voltmeter ranges (volt. Milivolt settings). Any reading of over half a volt indicates resistance eg. Bad connection.
Next, place one voltmeter test lead on the battery LEAD post ( - ), and the other test lead on any good engine ground. Perform the same tests by cranking the engine.

Next, place one voltmeter test lead on the battery LEAD post ( - ), and the other test lead on any good BODY ground. Perform the cranking test.

Last, check the PCM power relay for proper operation. It may be getting hot, or the contacts are bad, causing the PCM to lose power and thus, the engine dies. Refer to your owner's manual, or you can download the manual in *. Pdf form at the motorcraft. Com website under " Technical Resources" link.
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Tiny
Schrimpieman
Aug 28, 2009.
Since my other reply, I removed the plastic intake plenums. I thoroughly cleaned them and cleaned and degreased the gasket surfaces and channels. I replaced all of the Plenum gaskets. Pre-coating the gaskets, gasket surfaces and channels with a moderately thin coating of high temp Silicone. Reassembled and torqued properly. Then I let the vehicle sit for 24 hours to give PLENTY of time for the silicone to cure.

I double checked all vacuum hoses and connections. I'm hoping those steps eliminates any vacuum leak concerns.

The battery was disconnected during that entire time.

When warmed up it would stumble at stop lights which was an entirely new symptom. I swapped the hoses for the DPCE and that symptom disappeared

I tested it by sitting stopped with the parking brake on and in drive lights on, for about 10 minutes. It died after about 10 minutes. Upon restart, putting it back in drive, the rpm settled at approx. 750 rpm for about 20-30 seconds, then dropped to approx 600 rpm. Then it died a few seconds later.

That same pattern would occur every time once warmed up and stopped in drive the rpm would go to around 750, then drop to 600, then some times the engine would quit after anywhere from a few seconds to a few minutes.

”Does the engine slowly sputter to a stop, or is the stalling immediate? “

It is immediate as if someone turned the ignition off.

I checked the voltages and resistances as follows: Engine off cold.

- Bat terminal to bat connector = 0 ohms 0 vdc
- Bat connector to body = 1.3 ohms 0.001 vdc
- Bat connector to Block = 0.3 ohms 0 vdc

+Bat term to bat connector = 0 ohms, 0 vdc
+Bat connector to Alternator = 0 ohms 0 vdc
+Bat to + on Maxi Fuse = 0 ohms, 0 vdc

Engine on in drive, warmed up, lights on, after engine has stalled in drive

-Bat connector to block 0.148 vdc
-Bat connector to body 0.042 vdc

+Bat Connector to Alt = 0.224 cooling fans on, 0.139 cooling fans off.
+Bat Connector to Maxi fuse 0.042 vdc

" Last, check the PCM power relay for proper operation. It may be getting hot, or the contacts are bad, causing the PCM to lose power and thus, the engine dies.&Quot; That relay was warm, but not markedly warmer than some of the other relays. The coolest relay in the box was the one that was in the start interrupt position. I swapped the relay that was in the PCM slot with the one in the Start interrupt slot.

The relay swap was the last thing I did before coming in and writing this. The Windstar ran parked in drive with the parking brake on and chocked for about 5 minutes without stalling after the swap. I do not consider that an adequate test, so will take it out for a test drive a little later this afternoon.

Tiny
BCAnderson
Aug 29, 2009.
Just got back from a short term test. I drove about 10 miles in city traffic. Stopped about 20 times, and it did not stall. Then stopped in the drive way and let it sit in drive for about 10 minutes, and it did not stall.

Next will have to be a bit longer drive, but hopefully swapping the PCM/Start interrupt relay's cured the problem.

Tiny
BCAnderson
Aug 29, 2009.
Back from another test drive and the news is not good. Didn't get 2 blocks before it died at the stop sign. Then it ran ok through 3 more stops. Then at about 40 mph it started " bucking" Then it died as I turned a corner. And again when I pulled into a parking lot.

On the way back it started bucking again at around 40 mph, and gave two codes P0340 Camshaft Position Sensor Circuit Malfunction and P0401 EGR Flow Insufficient Detected.

Now that could be caused by the hoses connecting to the DPFE hoses being reversed, but I did not get a P1403 DPFE Sensor Hoses Reversed.

So looks like the next thing to replace is the DFPE. But before I do that, I'll remove the vacuum to the EGR valve and plug it and do another test drive tomorrow.

Tiny
BCAnderson
Aug 29, 2009.
I have access to a OBD reader. Here is the link to the instruction manual for it.

http://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Let me know if it will be of any use for this problem

Tiny
BCAnderson
Aug 30, 2009.
CORRECTION

The TPS was NOT replaced. So I changed it this morning and did a short test drive with no problems. Longer trip later today.

Tiny
BCAnderson
Aug 30, 2009.
Did a test drive this afternoon during the heat of the day 84 degrees F. Didn't even get 1 mile before it died at two stops. It also stumbled a couple of times at about 40 mph, and once at about 10 mph turning a corner.

Disconnected the vacuum line to the EGR and plugged it. Then took it for another test drive. It didn't die at any stops, but still stumbled a couple of times.

Tiny
BCAnderson
Aug 30, 2009.
I wouldn't replace the DPFEGR sensor. It wouldn't resolve the issue as you describe. The DPFEGR monitors the EGR sensor's job. You already took the EGR out of commission by disconnecting the vacuum line. If it continued stumbling at idle with the EGR vacuum disconnected, then the EGR is not at fault; neither is the DPFEGR.

Since you received the P0340 CMP sensor malfunction code, I'd investigate that next. You might not have received this code earlier because Ford OBDII systems go through a series of component tests with each test drive. I cannot pinpoint at which priority level the CMP sensor falls into this heirachy. If a certain component fails the OBDII test (which the vehicle does on its own during test drives), certain subsequent tests abort until the failure is resolved. Since you have a scanner now, you should see a P1000 OBDII Test Not Completed. This will remain until all monitors pass their onboard tests. Having the constant engine stumbling and malfunction(s) may have caused the OBDII system to abort all subsequent tests. Perhaps the P0340 CMP sensor test was far down in the heirachy level and never had a chance to set. Now it finally did, so you may have a better lead to go on.

The Motorcraft website (again) has an excellent technical library. If you're up for some reading, go to the technical link and download the *. Pdf article for OBDII Theory and Operation. It is organized by vehicle year. Download the year 1999 section and see if there is anything relevant to your situation. If it all seems overwhelming and technical, don't fret. I've been studying this stuff for a few years now and am still catching on to how all this stuff operates.

The CMP sensor synchronizes fuel delivery for each cylinder. It's possible that it is failing intermittently, causing your engine stumbling. The CMP sensor has two parts: The plastic " cup" you see from the top, and an aluminum shaft hooking up to the cam gear extending far into the engine block. Take each one off seperate and be certain to note the position of both the aluminum CMP housing and also the half-moon rotating vane in relation to the CMP housing AND ALSO when piston #1 is on TDC. All the tech manuals indicate needing a special tool to synchronize the CMP upon installaion. Nah. Tool not needed. If you need the Shade-Tree Mechanic's instructions (they are easy and really do work) let me know. I'll type them out for you.

Tiny
Schrimpieman
Aug 30, 2009.
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