95 Windstar hestates wont go over 60 mph

[briantman]

Hello,
I am looking for any help on a 1995 Windstar 3.8v6. The vehicle has a bad hesitation when taking off from a stop and when under a load. There are multiple symptoms I have noticed. The vehicle will not go over 60 mph. There seems to be a slight vacuum loss because the brake pedal gets inter. hard. There is a slight surge at idle not a quick surge but a definate sound change every few seconds. I have had the convertors removed temp. to ensure they were not the problem, no change. I have swapped out the idle air control, throttle position sensor, fuel filter, egr valve, dpfe sensor, coil pack, cam sensor, and the coolant temp sensor. The vehicle seems to be running lean. I have tried to check for a vacuum leak with starting fluid, found none. I have checked the fuel pressure and found it to be good. I have racked my brain to figure this out but have not come up with the right answer. Does anyone have an idea I have not tried?
Thanks,
Briantman

[ttaylor61]

Is the check engine light on? Assuming it is, what are the codes. Wiswind has an excellant thread at the top of this forum that identifies what the codes mean and suggested fixes for many of them.

[briantman]

No the check engine light does not come on. I have driven the vehicle approx. 70 miles and can not get it to come on.

[wiswind]

One guess at what it is, as you do not have a Check Engine Light (verify that it comes on when you turn the key to the ON position, but don't start the engine)......would be a fuel flow or pressure issue.

As you have changed the fuel filter, sadly, the likely cause would be the fuel pump.
On the '95, as with my '96, the fuel pump relay is inside the Constant Control Relay Module (CCRM).
There have been issues with the relay failing and causing NO fuel pump, but not a weak fuel pump.
There is a "sock" filter that is on the fuel pickup arm, but you have to remove the fuel pump to get to that.
Best to replace BOTH once you drop the fuel tank to get the fuel pump out.

A fuel pressure check, and even monitoring the fuel pressure while the vehicle is being driven would be a good check to verify if this is or is not the problem.
It would be best to do that before spending the time and money to replace the pump.....only to find out that I guessed wrong.
Another member had a similar problem with a newer windstar, found the fuel pressure to be marginal at idle, but it did not hold up under load....due to a weak fuel pump.
With NO vaccum to the fuel pressure regulator, the fuel pressure will be at a maximum value.
The fuel pressure regulator reduces fuel pressure as more vaccum is applied.
This provides higher fuel pressure in the fuel rail under more engine load (and the intake manifold vaccum is lower) and lower fuel pressure with less engine load (and intake manifold vaccum is higher).


The windstar does NOT measure fuel pressure or flow, so there will be no OBDII code set for this issue.

[briantman]

I have checked the fuel pressure again, found it to be at 48 at idle, I removed the vacuum hose from the pressure regulator and it went to 50 lbs. I drove the van with the vacuum plugged off and pressure guage on. No change at any speed. Fuel pressure registered the same. I tried swapping the ecm and the ignition module also but no change. I am not sure what the fuel pressure is supposed to be but that seems ok to me. Any other ideas? Is the fuel pressure ok? Thanks for any response.

[tripletdaddy]

My Haynes manual has the following pressures all in psi:
Key off, eng off 35-45
Engine at idle:
Vac hose on 28-45
vac hose off 38-50
Fuel system hold pressure 30-40
after 5 minutes
Fuel pump max pressure 65

Injector resistance(approx) 13.5 to 19 ohms

Some additional info I found in my manual on the test procedure for proper pressure and fuel pump operation:
Fully relieve pressure. Disconnect battery. Attach guage to test port Attach battery. Start eng, Check pressure at idle. then disconnect vac line to fuel pressuer reg. Watch pressure change during this step. The pressure should increase a lot as soon as the hose is disconnectd. If not, check for a vacuum signal to the fuel pressure regulator.

For the next step, I 'm not sure if they mean if the idle pressure is low or if it's low with the vac line off, but they suggest pinching the fuel return line shut and watch the gauge. If it doesn't rise, the punp is bad or there is a restriction in the fuel fedd line. If the prssure rises sharply, replace the pressure regulator. if you have rigid fuel return lines, I don't feel like typing up how to make shift that.

If the pressure is too high, turn off engine.Disconnect the fuel return line and blow through it to check for blockage. If no blockage, then replace the fuel pressure regulator.

I assume with engine on, take pressure reading with the vac line off the regualtor, then apply vacuum to it. The fuel pressure should decrease as vacuum increases and it should also increase when vac decreases.

Make sure there is vacuum in the hose going the pressure reg. Check for clogs, kinks if low.or none. they say if there is enough vacuum ( They don't say what it should be, but intake manifold vacuum should be 17 - 22 inches), then the high pressure by a bad pressure regulator.

Turn off ignition, after five minutescheck pressure. If the hold pressure is lower than spec:
leaky fuel line
The pressure regulator is bleeding fuel over to the return line
A leaking injector.
Bad fuel pump

Good luck

[12Ounce]

My guess would have also been fuel pressure. But, by measuring under driving conditions you have eliminated that pretty well.

You are saying that you have no "CEL", but that the lamp is working when the ignition is first turned on ... correct?

I don't think you mentioned spark cables ... they can be so faulty, causing misfires on most cylinders, that no particular cyl gets denoted as having a misfire. Worth making sure. ... and also, look over the cables to make sure they go to the correct cyls ... you may be surprised.

Have you tried a drive with the egr vacuum line disconnected and plugged?

After that, I would suggest opening up the upper intake manifold and having a look ... no telling what you may find.

[philkb]

See if you can get use of a scanner that will show data while the engine is running, and have someone ride along with you while testing. Murray's, as well as some other auto parts stores, may have such a scanner for "rent", such as the Actron CP9145 model. Then you can see if your timing is way retarded. If it were way advanced you would most likely get pinging, but maybe not. Since so many other bases have been covered, it seems like bad ignition timing could be the cause. Also, look for a parameter on the scanner reading called calculated load, or similar. If it's high, you may have a locked up torque converter clutch or similar transmission problem.

[wiswind]

It is a real long shot, but make sure that there is not some obstruction to the air intake.
It could even be the air filter, and I did not see that in your list of items.
But also verify that the opening to get the air into the air filter is not obstructed.
While you are at it, verify the path from the air filter to the throttle body.

If you don't find anything, you might try cleaning the Mass AirFlow (MAF) sensor.
I posted a couple of pictures of my MAF in the pictures that the link in my signature takes you to.
I am not sure if your MAF will look the same though.
One would think that a defective MAF would light a CEL, and the '95 IS OBDII compliant even though the requirement did not start until '96.
To clean the MAF, use non-residue electronic cleaner.
Most auto part stores sell it as MAF cleaner......same stuff.

Your '95 has a different intake that is unique to that year, as they went to the bigger, black nylon, upper intake manifold with the cross ports and IMRC in the '96 and newer years.
For that reason, I am not real familiar with your setup.

These are a couple of cheap and easy things to check off the list...and good to do anyhow.

[briantman]

Thanks for all of the replies I am trying each avenue. I forgot to mention in my first post that I have replaced the mass air flow sensor and all of the hoses with a different air box. The only reason that I have been able to afford to replace all of these parts is because I manage a local salvage yard. I have one of these vans that ran great until it blew a head gasket and the owner kept driving it. I will pull the upper intake later today and check for any obstructions. The timing is a direction I have thought about also intake damage. I have noticed that when you erv it up even at idle it does backfire sometimes, just noticed this the last couple of days. The CEL does come on with igntion like it should so I am assuming that it works. I did try another ECM but there was no difference. I was told by one Ford tech that the engine was bad, but that was after he told me the head gasket was blown. I have driven this thing formore than enough time and it has never overheated. I have also noticed that sometimes the brake pedal gets rock hard. I am sure it is related somehow. I will try some of these things mentioned today and let you know if anything works. Thank you again for all of your ideas.

[wiswind]

There is a big fat vaccum line that goes to the power brake booster that is behind the master cylinder.
On the booster end of the hose is a sort of "check valve".
I am wondering if the brake symptom may be leading you into there somehow.

I have found some mechanics that seem to be quick to talk about the head gasket, particularly on the '95, which is the 1 year that the 3.8L windstar was prone to this failure.
However, I would expect some other symptom, like coolant usage.
It is possible for the head gasket to fail otherwise, but the issue that the 95 3.8L windstar had was relative to a small clearance between a coolant passage and the cylinder.
Without coolant loss or air getting into the coolant system, head gasket becomes less likely.
Besides, I don't like expensive solutions anyhow.

[tripletdaddy]

Could you elaborate on the way the van acts when it starts to and actually does limit out on its power/speed? With the hard brake pedal being at least one symptom of low vacuum, you should test the intake manifold vacuum to eliminate it as a problem. As Wiswind indicated, the fuel pressure is inversely proposrtional to the vac press. Another thought for a quick test on the vac press, is to feel how hard the brakes are at your maxed out condition. Good brakes would indicate good press at maxed out condition, which should then give you the proper fuel pressure, but you must measure this. If you are certain you have proper fuel pressure at this maxed condition, that may rule out the fuel pressure regulator, which I have some suspicions of. Good luck

[briantman]

Hello again to all of you trying to help me figure this out. I removed the upper intake and checked for blockages or any problems. I thought the gasket was showing signs of leakage (got happy for a moment). Replaced and retried. No avail. I know you are not supposed to mess with the cam sensor adjustment but since I'm running out of options I thought I would try it. No change at least not drastic. I tried unhooking all of th O2 sensors, just in case. I did notice it will back up a little better but not much. I drove it for about 20 min and it right back to where it was. I guess my next step is to remove the timing cover and check the chain to see if it has jumped. I am about out of options, next step JUNK IT. I have never found one I could not figure out till now. I did check the valve to the brake booster (ok). I am starting to wonder if the shop was right and the engine is bad. I tool off the oil cap and did not hear blow by like you normally would with bad rings. I just can't accept it to be a bad engine. When driving sometimes you can fell it get a "surge" and it will accelerate and go. This will only last for a second. I have run two tanks of gas with cleaner through it just in case. Any other ideas I'm open for suggestions. Thanks again...
Briantman

[LeSabre97mint]

Hello

How many miles on your 95? Have you concidered the timing chain? It may have developed slack and causing late valve timing. My 95 has 230,000+ and it's running well.

How long have you owned this van? When did it start running poorly?

Regards

Dan

[wiswind]

Removing the timing cover is easier said than done.
It is a very involved job.