I haven't had much time to work on this van this past week. I have read thru these replies several times, and remember an observation I made, and was wondering if it means anything?

When I changed the fuel filter, which sits on the rail in front of the fuel pump, I remember removing it and the fuel just leaked out slightly. There was no pressure on hissing, nothing. I did this about 30 minutes after I shut the van off, and did not relieve fuel pressure in any way. The gas cap was on, I just removed the clips, loosened the clamp that holds the filter and took it off.

Aren't these systems under pressure, or does it lose pressure from sitting the 30 minutes? I don't have a FP guage to check pressure with.

Thanks again,
Frank D

 

frank when i replaced my fuel pump in 87 e150 van i also had no hissing or any thing like that ,just a lil gas leak

 

Definately disconnect the battery and let it sit a bit. My 89 had a like problem that was cured by the disconnect of the battery.

check that fuel pressure. 35 psi is nominal. all the time.

for other ECM/sensor values get Probst's EFI book. Very good for troubleshooting.

I have the 5.0L ECM/Computer out of my 89 E-150 and its up for sale if you want to go that route. PM me. I installed a 351 and it required a new ECM.

 

It's not 35 PSI all the time because the fuel pressure reg is specially designed to be 35 psi versus the intake manifold pressure. With the engine running and vac present at the intake, gauge pressure will go down.

 

Thanks Dannym......Any idea based on the info above what the problem/problems could be? Its too cold now, and I am too busy, but the next part I change is the fuel pump. I have one already so my cost is only my time to put it in. The one in the van now is the original.

Thanks
Frank D

 

True. Let me be more specific..
KOEO = key on engine off
ER = engine running

static pressure at KOEO with pump running = 35 to 45 (I see 35 on my engines)

ER at idle, presure lower than KOEO
ER at wide open, about the same as KOEO
ER at idle with vacumn hose disconnected same as KOEO

Residual Pressure = turn off the engine, it should hold pressure and stay within spec for a minute. a tighter spec is no more than 2 psi per hour drop.

fuel volumne should be about 5 oz per 10 sec when checked at the return line after the pressure regulator, fule pump energized.

hope this helps

 

Looks like I will be getting a Fuel Pressure gauge soon.

Again thanks for all the replies.

 

I'm assuming this is an EFI, not carb.
The fuel system is such that both the tank's low pressure fuel sump pump and the high pressure pump (inside the beam under the driver's seat) blindly runs at full speed all the time the engine is running. The pressure is regulated by the fuel pressure regulator which simply opens up at 35 psi and bleeds extra pressure back to the tank through the "Return" line. You may have noticed there are 2 lines going to each fuel tank. This is why.

Buying a high pressure (not carb pressure) fuel pressure gauge is probably pointless (and expensive). That hooks up to the schrader valve on top of the fuel rail and any tire gauge with a locking lever can do it too. You cannot check it while running due to the intake vac factor. Really just lock on the gauge, turn the key ON (not RUN), the pump runs for a sec or two, repeat. That will build up full pressure under 0 intake vac.

The fuel pressure reg can and does malfunction by tearing its diaphragm. This will leak out fuel into the intake. Easy to test- take off the vac hose from the reg. If there's fuel in it, the reg is leaking through it!

I don't recall fuel spewing out either. Maybe I thought to bleed it first. Probably a little leakage over time is normal, that wouldn't affect running in the least. Nothing says the reg has to make a perfect seal, and it'll just go back to the tank.

Things to test- timing chain. Rock the crank through the harmonic balancer bolt and see if the dizzy rotor turns along without a great deal of slack. Maybe ignition module, but I think that just causes it to die.
At this age, it's a GREAT idea to replace the fuel pump. Likely it could fail at some inconvenient time in the next few years. Throw the old one in back if you don't have to pay core on it.

The tank sumps are more likely to fail. However I've discovered the high pressure pump actually seems to draw enough vac to pull the fuel up. Because I apparently drove for years with that thing disconnected (true story). Might impair the high pressure pump a bit, but I think those things have plenty of extra pumping capacity.

 

Oh yeah check for vac leaks too. The stock hard plastic "cocktail straw" harden and crack where they go over the passenger side exhaust manifold. The steel "coffee can" vac reservoir behind the main battery will be rusted out by now.

Air charge temp sensor. Dunno much about it, though I want to replace mine just on principle at this point. Glad you reminded me! I assume it just changes resistance with temp, but I have no chart. In any case if it collects gunk it will not operate exactly as intended because it will be slow to change with temp (but once the engine's warm it shouldn't change really fast). Well, it can inhibit timing a bit but I don't think it can do what you describe. But a crack in the vac line going to the MAP sensor probably can! And it'll come and go too.

Some people swear by "plugged catalytic converts" being the problem. While I'm sure this can happen, I have my doubts about how often this actually happens. Some people seem to look at any problem and blame the cat every time. This is not an easy/cheap thing to swap out, can't be tested, and is potentially an illegal modification for emissions purposes.

I didn't see where you checked the codes. That's actually step 1, even though half the time it yields no useful info on these. I had a no-start due to slipped timing chain and it didn't say diddley!

 

Thanks again Danny,

This is an EFI I-6 which has no timing chain it uses 2 helical gears. Timing is on the mark when I checked it. Early on in the thread I had mentioned checking for codes, I always come back with code 11 meaning system is OK. As you mentioned it yielded no useful information for me either, LOL. Got to love it. I had a mechanic also check and verify I was correct, and he was puzzled as well.

As far as I can see there are no bad connections, or vacuum leaks, which is what lead me to replacing all the parts I mentioned in the beginning.

The only parts left to change at this point are the EGR, Computer, CAT converter, and Fuel Pump, or sell it and move on. That is something my wife would like to see me do, but I don't give up.

I am certain I will stumble upon it. A buddy of mine told me not to bother buying an FP gauge and that is why I held off. Since the FP is sitting here I might as well replace it and see if anything changes. At this point there won't be much else to change.

I guess if the FP doesn't help I am going to have to go thru each sensor with a volt meter and test then one at a time.

Thanks as always,
Frank D

 

"I am going to have to go thru each sensor with a volt meter and test then one at a time".

IAC=7-13 ohms

ECT & ACT Verify resistance DECREASE when heat is applied (heat gun or hair drier).

TPS= linear resistance INCREASE (no jumps no OL) response from CLOSE to FULL OPEN
Volts =.5 Closed 1-5 volts increasing to full Open (Signal Return)

Check for Vacuum leaks with an UNLIT propane torch around vac lines and intake gaskets, engine will rev up when you find a leak.

 

I had some time today to work on the van again. During the week I left it with a mechanic, $75 later no idea, no codes every thing tests OK. "It could be the fuel pump, or the computer"?

I had a fuel pump and put it in today, it did nothing. I didn't disconnect the battery to install the fuel pump, I didn't think it would matter.

It still starts stalls, starts, then surges bogs down a little and has no power when cold. Once warm it runs like a top. If you gun it when cold, it feels like the choke is too far open. Van has EFI.

New parts: TPS, IAC, CTS, ATS, O2 Sensor, Map Sensor, FP regulator, Fuel Pump, major tune up, cleaned injectors, EGR position sensor, cleaned EGR and checked operation, no vacuum leaks, new thermostat. Cleaned throttle body.

How to I check the computer?

Thanks for all the help!
Frank D

 

my 1987 ford van did the same as yours after i replaced as much as you replaced>> the only diffrence is when i checked the vac canister it had broken vac lines in them and i went to junk yard got vac clips rejoined them in cannister and van has been running beter ever since i did that! i agree with danny in these vans ford hid alot of vac lines behind the battery area and running along the passenger side engine area where it gets very hot ,you have to look very closly 1 @ a time and if it looks bad change the vac line quickly! also change the brand of gas you use and see if that helps ,some gas stations sell cheap reformulated gas that will run like crap .have you cleaned out the throttle plates with air intake cleaner? if not try to clean that out and see what happens.from here on out its 1 step at a time with your van,my van acted like this for about 1 month and it was giving me hell even after changing out all my parts,it took me to discover my vac lines at the cannister to get it running better.have a great day and hope this has helped.

 

Thanks,
I will have another look, the throttle plates are squeeky clean, and I tested and looked high and low for a vacuum leak.

Did you hook up a vacuum gauge? I did and it showed no leaks, I went around the manifold etc with propane looking for leaks. I will have another look at the canister and pull the battery, and inspect vacuum lines in that area. Thanks!

Frank D

 

You don't need (or want) to go with the Ford hard plastic vac lines again. The nipples on either side accept std rubber vac tubing.

Frank one thing I would consider is the coolant temp sender. On my '87 302 there were 2- one sits near the intake, has a single push-on stud, that only goes to the gauges. There's another (not sure where it is, actually) that has a formed plastic connector with 2 pins. That tells the computer to switch from cold to warm modes and is separate from gauge wiring. Maybe it's not working or not connected properly and the computer's operating as if the engine is warm when it's still cold.