Hope somebody has experience with my problem. I have taken this truck to several mechanics and even a local Ford dealer here in San Antonio, and nobody can give me a solution that works. They ALL come up with something, but it is never it.

The problem: For several years.....yes years.....this truck, when it is hot outside, but at cold startup, or after it sits a while, is hard to crank over (cranks but struggles to start). Then when it does start, unless you give it gas it will die after a few seconds. (I stress: this happens when it is WARM or HOT outside, not when the air temp outside is cool) If it does die without me giving it gas, it will crank right up on the second try. But it still runs rough. Also will not idle up fast except if it's cold outside. I have tried everything I can think of after many hours of deliberation and repairs to no avail. Truck has 203K miles, but problem started with about 150K miles. It just seems to run bad in general too and idles very rough. If I go somewhere and it sits for say 30 minutes, it will be hard to start again.

I have done the following over the past 6 years and none of these has fixed the problem.

1. replaced all fuel components including high pressure pump,not once but twice (one mechanic told me the replacement I put on had low pressure, so i thought I had a bad pump), also both low pressure pumps in both fuel tanks, fuel tank vents, fuel reservoir, fuel filter, fuel regulator, fuel injectors sonic cleaned off truck (checked for leaks before installing by connecting to fuel rail and pressurizing. Found no leaks) Ran 2 cans of fuel injector cleaner (3-M) connected to rail to clean top of pistons. Had rear fuel tank cleaned out.

2. Another mechanic shop (popular radio show host shop) told me to clean injectors which I did above, and replace EGR valve. I did these in addition to dipping upper and lower intake, and new lower intake gasket. Saved $800

3. basically have replaced any sensor you can think of. Nothing ever shows up on a scan. Replaced knock sensor, air sensor, MAS sensor, vaccum regulator, new (rebuilt) computer, O2 sensor, Air bypass valve on intake(including spacer kit), engine coolant sensor, TAD and TAB sensors, EEC power relay switch, some type of switch in the distributor, TPS

4. keep tuned up. new plugs , rotor, wires, cap (all motorcraft), new coil, check timing/had timed when dist work done. Know how to check timing myself and have rechecked and rechecked. However I have never replaced timing belt.

5. replaced original colored vacuum lines with rubber, replaced fuel tank vent lines with new copper to fuel canister. Fuel tanks were not venting.

6. Emissions parts replaced: air bypass valve (near air pump), new air pump, air control valve. Have NOT replaced check valves. New catalyitic convertor.

There could be something else I'm forgetting. My next option other than parting this truck out, is to replace the 2 check valves that go to the catalytic convertor. Could one or both of these be stuck closed maybe? The Ford dealership I took it to, didn't charge me for scanning it since they could not definitively find the problem. They even kept it for 2 days and came up with "replace the air bypass valve on the intake" which I did myself. No help.
My chilton's manual shows a purge regulator valve near the fuel canistor under the hood, but I can't find anything with wires there. Does this truck have one? I figure I'll replace everything until I find the problem but it's getting expensive.

If somebody out there knows what my problem is, and has had experience with this problem, and I do it and it fixes the problem, I will send you a cashier's check for $100. That's how desperate I am to fix this problem. It's driving me crazy. I still love driving this truck and have since it was new. I want to strip it and repaint it with new moldings and whatnot, but I won't do this if I can't get it running right. Your help is appreciated. Thanks

Darryl H. in San Antonio, TX

 

Almost sounds like a heat issue with the ignition module, not sure if that's what you meant by 'some type of switch in the distributor'. If so there is a chance the cam is worn, of course then it should run rough all the time. That could possibly cause the hard starting when it's hot tho.

Edit- I guess you did say it runs rough all the time, sorry. I think I would seriously consider pulling the timing cover and putting a chain on it if you haven't ever done it. With that many miles on it it is OVER due for one. I don't know of any easy way to check the cam besides pulling it apart.

 

bigdnsa,

I'm so happy I'm not the only one.
I've been fighting the very same issue for 2 years. Replaced everything (some pieces twice) except ECM.

One thing I found out on this site and on fordtrucks.com: parting out and total rebuild DOES NOT fix the problem.

I'm not sure if replacing the timing chaing will fix this problem. I checked mine. I don't have gap at all.

I "upgraded" TFI module with heatsink from 1988 Thunderbird. Had to build special cable for this thing. There's no way it overheats now. Still the same. When I park it at work for hour or so it would die at idle. But second start seems fine. Plus rough idle. Plus occasional ping on freeway. All standard f150 issues.

I mentioned as it get colder it runs better. So, the latest thing i'm going to test is put Air intake Sensor out (I have several of them now ) and let it hang on outside air.
I'll let you know if it's any help.

Please, post your results here.

 

Well,

This issue is deffinately temperature related. Oh, well since I don't have MAF, it should be. I know that engine is running lean. And i'm tired of changing sensors. I've changed MAP twice already.

People, please point me where to search for the fix. As I said above it's been 2 years of battling on and off. It's been a first engine that really puzzled me. Viva Ford!.

 

Have you checked the EGR sensor? While the engine is running pull the vacuum line off the EGR valve and see if there is a change. I had this problem on my truck. Was lucky enough to find this site.

 

Well where to start, first place to start if you haven't already done so is to replace ECT sensor and IAT sensor maybe $40 for both.... Next thing is swap in another ECM and see if the problems still occur. If the ECM checks out there is another possibility, check out this article http://fordfuelinjection.com/files/TFI_Tips.pdf (scroll down some) you may have the wrong TFI module. I would recommend going directly to Ford for a TFI module instead of an aftermarket supplier or retail chain. Good luck and let us know

 

Does the truck smoke at all, either when the problem happens or normally?

It really could be several things, but it does sound like an IAT problem. I'd be interested in knowing if any of the following made any difference (if you want to try these, do them one at a time and check for any improvement):

Unplug the spout connector
Unplug the IAT
Unplug the O2 sensor

Other that that, it's hard to say without more info. It would be nice to know what the fuel pressure is at idle, and when this problem occurs.

One other thing you could try is to hold the gas pedal all the way to the floor when trying to start it, and see if that makes any difference. There may be an issue with the TPS and it's WOT fuel cut-off.

 

Before I forget, on a side note, you should also know that it's not a good idea to use copper lines in place of rubber or steel fuel or brake lines in vehicles. Copper is prone to cracking easily when subjected to vibrations, and can create a very ugly situation when used in a car or truck.