Can't seem to resolve this problem..please advise

[wtd]

Is the gas cap original? It could be bad. You should still have some pressure after 30 minutes.

I doubt its a fuel pump issue or it would do it all of the time.

Have you checked the throttle body gasket? What about O2 sensors?

I think the vehicles that have duel tanks also have a secondary fuel pump along the frame rail somewhere. There is also a part along the frame that all of the fuel lines go into and out of. My neighbor has an 88 F150 truck with the duel tanks and we took this part apart and cleaned it. It seems like I remember it had some type of diaphram in it.

Usually when a fuel injected vehicle runs badly when cold, it has too do with some of the sensors that control the vehicle when its in its open loop mode. These sensors could be bad enough to make the truck run bad but not set off the Check engine light. I know you said you have replaced most all of the sensors. Did you use OEM parts or aftermarket?

It also could be the computer. I'll try to think of other things to check for.

wayne

[ January 14, 2006, 01:01 AM: Message edited by: wtd ]

 

[demarpaint]

quote:

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wtd
Member
Member # 122

posted January 13, 2006 10:47 AM
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Is the gas cap original? It could be bad. You should still have some pressure after 30 minutes.

I doubt its a fuel pump issue or it would do it all of the time.

Have you checked the throttle body gasket? What about O2 sensors?

I think the vehicles that have duel tanks also have a secondary fuel pump along the frame rail somewhere. There is also a part along the frame that all of the fuel lines go into and out of. My neighbor has an 88 F150 truck with the duel tanks and we took this part apart and cleaned it. It seems like I remember it had some type of diaphram in it.

Usually when a fuel injected vehicle runs badly when cold, it has too do with some of the sensors that control the vehicle when its in its open loop mode. These sensors could be bad enough to make the truck run bad but not set off the Check engine light. I know you said you have replaced most all of the sensors. Did you use OEM parts or aftermarket?

It also could be the computer. I'll try to think of other things to check for.

wayne

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Hi Wayne:
The start stall, and other issues are all the time, and it doesn't matter what tank its running on, or which gas cap is on what tank. I have switched gas caps from the front tank to the rear tank, it made no difference. I tried another gas cap borrowed from another E-150, it didn't help.

The only after market part I used was the ACT sensor, all others were Ford Motorcraft.

My feelings from the beginning were the same as yours, it had to be one of the sensors controlling the mixture at startup. That's why all those parts were changed. I was told by a mechanic that the odds of it being the computer were very slim in this case.

Then I thought maybe, the fuel pump was weak, or lacking volume at start up. I must have checked for a vacuum leak 10 times now, and had a friend double check as well.

The throttle body gasket appears to be fine, the throttle body is clean, and the o2 sensor was replaced.

Each time I do work I disconnect the battery cable for no less than 30 minutes. You can then feel the van "relearn" when I am running it again.

At this point I am considering trying another mechanic, but have a feeling its going to be another $75 out the window. The last guy was stumped as well.

The good news is I have a new FP sitting on a shelf in the garage, so installing it won't set me back anymore money. At this point I am just tired of working on it and seeing no results, but I am the kind of person that doesn't give up.

Thanks again for all the great replies.
Frank D

[ January 14, 2006, 08:29 AM: Message edited by: demarpaint ]

 

[Brent]

Yes you should have fuel pressure at least 30 minutes after shutdown. Ford has had fuel pump check valve problems and with dual tanks can even allow fuel to be pumped from one tank to the other.

A fuel pressure gauge is the first step to diagnose the fuel pressure problem.

Ford also offers inline check valves they used in the F150 recalls for the late 80's and early 90's trucks.

I just fixed a 93 F150 with an inline check valve. However, my problem was long crank times and pumping fuel from the rear tank to the front. My problem was not stalling after start.

If the fuel pressure can be ruled out, you could hook up an inductive timing light and see that the firing continues during the dying cycle. (put the timing light plug wire lead on the coil wire) To make sure you have injector pulse during the dying cycle you might be able to use a stethoscope.

Brent

 

[demarpaint]

Thanks Brent.

Is the check valve built into the OEM pump? The only things I remember seeing was the tank selector, the high pressure pump, and the filter.

When starting the crank time is very short, and it fires right up, then stalls, restarts, then I noticed it runs a while and stalls as if it ran out of gas. Always lacking power until the engine has been running and warms up a little. It has to run about 3-5 minutes before I can even move it without it stalling.

Restarting is never a problem, funny thing is the start stall issue is worse in the hot summer. Winter starts were never a problem until this year, now the start stall issue is all the time.

I am now trying to get my hands on an FP gauge.

Once again thanks for all the great info,

Frank D

 

[demarpaint]

I had a few minutes today and broke out the code scanner again. Ran thru the tests and came up with code 11 meaning everything OK.

Started it up, and it did the usual start stall, ran for about 30 seconds, died as if it ran out of gas. Restarted and it did the same thing, allowed it to warm up it was fine.

If I choke off air to the snorkles that go to the throttle body with a rag or something it will start and run fine not stalling. I let it sit over night and tried this experiment and it started perfectly. It would never do this under normal starting conditions.

Why?

Thanks for all the help and putting up with the numerous questions I ask.

Frank D

 

[demarpaint]

Thanks Brent,

Seems vacuum leak keeps coming up in variuos replies and its worth another look. I checked and couldn't find one, but will spend some time tomorrow and try again. This time I will pass an UNLIT Propane torch around all areas that could be leaking vacuum and see what I come up with.

Thanks again,
Frank D

 

[Brent]

Tough to diagnose problems without being there. With this information I would look for a vacuum leak. Maybe intake manifold gasket or leaking brake booster?

The computer really doesn't control fuel mixture during open loop and could explain the fact that it runs better when warmed up. The computer could be richening up the mixture during closed loop operation to compensate for a vacuum leak.

Brent

 

[demarpaint]

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 boggs 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

 

[StressSolutions]

Wow, are you sure you're from NY, seems like you're too patient!

My meager thoughts point toward the switching valve/check valves, etc that Brent mentioned. I have a 94 F150, 4.9 dual tanks, and have had some similar problems. Rear tank fills front tank, start/stall, etc. Good luck, you deserve a medal for this one.

 

[demarpaint]

Thanks StressSolutions, (I can use some stress solutions!)

Yes I'm from NY and have a lot of patients but this thing is testing it every day!

I read thru some TSB's and came upon this:
ISSUE: A rough idle, hesitation on acceleration, and/or a stall after start-up with no DTC's present may occur on some vehicles. This concern is noted at odometer reading greater than 30,000 miles. This may be caused by the throttle body gasket leaking, resulting in internal throttle body air passage due to a vacuum leak.

Action: Replace TB gasket with a revised TB gasket and they give a part #.

I have a good idle, and no hesitation on acceleration once warmed up. But when cold lack power and stall. No vacuum leaks, but, this mentioned internal leakage. I have no idea how to detect that so off came the TB and I am waiting on the gasket.

Inside of TB was clean as a whistle. Hopefully I will have the gasket Wednesday, and find the time to put it back together before the weekend.

Brent, thanks for the PM I will check into that site as well.

Frank D

 

[demarpaint]

I will keep you guys informed about the TB gasket replacement. Not sure what the TB gasket is going to do, but for a few dollars it was worth a shot.

Can you have an internal vacuum leak in a Throttle Body that wouldn't be detected with a vacuum gauge?

Someone also mentioned late ignition timing to me. Base timing is on the mark.

Thanks
Frank D

 

[TheLoneRanger]

Frank, keep us informed on the TB gasket. If the new gasket dosen't help, I'd go back and check the MAP wiring. Even though the sensor is new, it sounds like there's no MAP signal during open loop operation.....?
(I'm basing this on the low power and 'rag stuffed into intake tube' trick -- obviously a lean condition.)

 

[ninjalogan]

demarpaint,

Pulling that distributor might not have been a bad idea. Inspect the inside of your old cap, and check the distributor closely. I had one that was bad on my 88 pickup and it gave me fits before I could figure it out. Retarded/advanced timing, sputtering, stalling...took me awhile to get it and even then only did so with a friend's help.

They aren't cheap, though, so be 100% sure (and then some) before replacing.

 

[demarpaint]

TB Gasket is done. Inside was clean very little carbon. Here's what's happening, start stall, restart runs a little less than one minute, stalls as if it ran out of gas, restarts runs fine. Seems to have a little more power, or maybe its just me?

When the rain stops I will continue looking for vacuum leaks, but have a feeling I am wasting time, been down that road before. I am going to try to remove the EGR make a plate to block it off and try to see if maybe the EGR is bad. It moves OK, had no carbon, but maybe its not seating properly. Will have a look at timing with the SPOUT connected. .

I had checked the distributor, by swapping one from my brothers van, made no difference. Wish I could swap computers with my brother, but this van is a stick, his is an auto tranny. Numbers on the computers are different.

Thanks,
Frank D

 

[demarpaint]

quote:

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TheLoneRanger

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Frank, has the base idle ever been adjusted? With the IAC unplugged, the engine should idle very slowly, about 400 rpm, and almost quit. This allows the IAC to increase the idle speed as needed. I'd check the base idle just for reference.....

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No, I never adjusted the base idle.

I pulled the EGR valve today and made a blocking plate out of cardboard to render the EGR inoperable. It did the same start stall routine. So the EGR valve is good. Tomorrow I am going to check the timing with the spout connected, and block vacuum to the FP regulator.

What's odd is it does the same exact thing as if it were programmed to start stall, restart run 45 seconds and stall again, like clockwork.

Thanks
Frank D

 

[TheLoneRanger]

Frank, has the base idle ever been adjusted? With the IAC unplugged, the engine should idle very slowly, about 400 rpm, and almost quit. This allows the IAC to increase the idle speed as needed. I'd check the base idle just for reference.....

 

[demarpaint]

Update:

I removed the EGR valve and blocked it up, made no difference.

Took the vacuum line off the Fuel Pressure regulator and blocked that up, it started and ran fine. Went looking for vacuum leaks with spraying carb cleaner on intake manifold, and where ever I could find a vacuum hose, no leaks.

Then I sprayed the EGR diaphram with carb cleaner, and idle increased by about 200 rpm on the tach.

Still puzzled because blocking up the EGR made no difference, but plugging the vacuum to the fuel pressure regulator had it running like new.

Fuel pressure regulator is new, EGR is original and appears to work. I don't have a vacuum pump so I am trouble shooting the EGR the best way I can.

Thanks
Frank D

 

[TheLoneRanger]

Frank, plugging the FPR vacuum gave you higher fuel pressure at idle, therefore enriching the mixture and appearing to 'cure' the lean condition.

You shouldn't get a higher idle by spraying the EGR diaphrahm. I suspect the diaphram is cracked and allowing a vacuum leak through the vacuum line from EGR to the manifold. Try unplugging the vacuum line and capping it, and then see how it starts and idles. (As you know, the EGR is normally closed at idle.)

 

[demarpaint]

Yesterday I spent most of the day looking for a vacuum leak.

I plugged up the EGR to isolate it, and still had the same problems, changed a few vacuum lines that were old, had no luck. All the while I kept the battery disconnected.

A few hours later I put it back together, and it did the usual start stall that's been mentioned in my other posts, in fact it was worse I think. So I called it a day.

This morning I went out to check timing but didn't have the light. So I started it up to search for a vacuum leak again. Much to my surprise it started, stalled and ran perfect.

What's going on now?????? I'm not complaining just wondering.

Thanks,
Frank D

 

[jc1990]

hate to tell u this but get rid of it i have a 90 ford hightop conversion van with 5.8 engine ive had it 4 yrs it,s a terrible van ive had all kinds of idling problems surging dieing out these old ford vans are crap buy a gmc or chevy much better van