Hello and Holidays!

I first off want to thank those who have replied to my posts, you have been extremely helpful. I have a mint condition garaged 88 E-150 4.9L that sees very little use and I guess that has contributed to some of my problems. Winter is a slow time for me so I have the time to work on it.

Here is what is still happening and the parts I have replaced. No codes when checked.

The van starts and stalls, and seems to run lousy (weak) for the first 2-3 minutes, then it runs fine but a little rich, very strong when warm, but fails NYS emmissions.

Parts Replaced: O2 Sensor, TPS, Map Sensor, Thottle Air Bipass Valve, Fuel Pressure Regulator, Thermostat 192*, Coolant Temperature Sensor, Complete Tune-Up, Plugs, Cap, Rotor, Wires, Air and Fuel Filter. I cleaned the throttle body and plates, oddly they were extremely clean to begin with.


I notice once its warm and running it runs strong and smooth, however around 40-50 mph it feels like it is bogging down ever so slightly. Above that speed its very strong! Pulls like a freight train up hill.

BTW its a 5 speed stick. Clutch is perfect no slippage.

Could the hi-pressure fuel pump be going? 63,000 miles original, I have dual tanks and the situation exists on both tanks. Or could it be the Air temperature Sensor, I tossed enough parts at it.

Thanks and happy holidays,
Frank D

 

try to check all the vacuum in it and also clean or replace the egr valve,it may help it out.

 

try to check all the vacuum in it and also clean or replace the egr valve,it may help it out.

 

Will do.........thanks

Do you think the FP could be at fault? All vacuum is connected and good. I cleaned the EGR value about 20,000 miles ago it was fine, but worth having another look at it.

Frank D

 

Make shure you replace the sensor that goes on top of the EGR.Some times its not the EGR valve,but the sensor.

 

Do you know which parameters of the emmissions test you are failing and by how much? That could point you in the right direction for a fix.

 

I don't have the parameters of the emmissions failure, all I know is it was rich, and NOX was high. Those were the comments made by the mechanic that tested it.

The start stall has me bugged right now


Thanks
Frank D

 

Aren't these sensors supposed to trigger a code if they are bad? This van shows code 11, meaning all is fine!

 

Brain box needs a brain, these problems can be a pain. I believe you said you had changed the Spark plugs, when you did was there any evidence that one or more cylinders had been burning rich (heavy deposits on the electrode). If you do not recall it might be good to take a fresh look, if you do find evidence then you may want to check the fuel injector(s) associated with the cylinder(s). Might have one or more not closing all the way causing the rich problem. You did say you have not used this vehicle much which may have lead to varnish build up, check out the fuel rail and the injectors closely, it does not take much to cause problems.

 

Thanks,

Plugs according to the pictures in the shop manual were "normal", I could have probably resued them, they only had about 15,000 miles on them. I replaced with new plugs only because it was a PIA to get them out. The cap had some signs of wear, normal.


The new plugs are in about 2,000 miles I will have another look.

From what I am gathering, its not the fuel pump.

Funny thing is the start stall issue is more obvious when the outside temperature is hot 85* and above. It will start, and stall several times then surge a little and run fine. In cold weather it starts and stalls maybe 2 times and runs fine. When it stalls it almost feels like it's run out of gas.

Would the Air Charge Temp Sensor be a possible cause? Just thinking out loud here.

Thanks
Frank D

 

I had seen a procedure for checking the sensors with an Ohm meter but do not recall what values they listed as being acceptable.
What you are describing sounds remarkable similar to what my 88 F250 (351W) does, especially in warm weather, I have not had the truck long so I have not persued the fix yet (working on all the other problems), I will find the values and procedure for checking the various sensors and get them to you unless someone else has them, it will have to be tommorrow though as I am at work and don't get off till 11P. Stratagy could be usefully in getting to the bottom of the problem, no since in buying parts that aren't fixing it. What do the say; The truth is out there...

 

I am getting tired of it! I like the van, but enough is enough. The good news is its not my primary vehicle, so I let it sit until I get myself motivated to play with it.

If I can psych myself up I will pull the plugs again tomorrow.


Yep the truth is out there...........

Thanks

 

I did some cleaning up in the garage and found the old plugs I had replaced 2,000 miles ago, and they were all normal. I then ran the van and pulled the plugs with 2,000 miles on them, perfect condition as well. Put the code scanner on and looked for codes, all good according to the scanner.

Still puzzled. but glad the plugs were good.

 

Took it for a run today, starts, then stalls a few times, then surges a little, stabilizes and runs perfectly. No codes stored. Seems to lack power when its cold.

Had a mechanic take a look, he is guessing, maybe computer is bad? ACT sensor? He couldn't pull a code either.


Any other ideas?

Happy New Year
Frank D

 

> maybe computer is bad

Very unlikely as in .001%.

re:fuel filter

Which one did you change? You might have two. There might be an additional filter near the rear fuel tank between the high and low volume pumps. It will look like a small black screw on cannister.

re:TPS
On your year vehicle do you have to calibrate it with a DVM?

Remove your snow shield and spray the spring near the throttle. Sometimes the spring sticks.

> I have dual tanks and the situation exists on both tanks

Considering you failed the emission test, here is what I think your problem is. Your year vehicle probably has two charcoal cannisters, one for each tank.

I do not know when they stopped using them (carb/efi). They should be in the pass. side frame rail and at least one is probably bad if you have them. The only real way to tell is to take them out of the vehicle and see if fuel is pooled in the bottom. There will be a felt type pad in the bottom and if it is soaked with gas then the valves and/or cannisters are bad.

Before I did this, I would change the gas caps (myself, I would put locking ones on to protect the engine and gas$). If you decide to do this, e-mail me and I will tell you how to get matching locking ones.

Then check the vacuum/return lines from the tank selector valve. Then check the "check valves" going to the charcoal cannisters. A few of them are exposed in the pass. side engine compartment/wheel well and can get broken which will cause driveability problems.

The reason for checking this is your dead spot at 40-50 and failed emissions, this points to a problem with the cannisters/valves/vacuum/tank selector valve.