1988 F250 302 5.0
For the past few months while driving the Truck, it would hesitate from time to time and buck. I was assuming it might be the injectors but now I think it might be a bad fuel pump.

Yesterday it started but then it stalled after I tried to drive. I let it sit for a bit and it started up but I had to pump the gas pedal to keep it going and it finally started but I was afraid to take the truck for a test drive.

Today I went to start the truck and it started but when I went to drive it stalled out. If I would let it sit for a bit it would kick over and start but I would have to keep pressing the pedal to keep it going and finally when it gets warm it stays running.

I’m assuming it’s the Fuel pump that’s located on the left rail under the driver side truck rail is going bad.

Any thoughts? If I take the pump out, what’s the best way to test the pump?
Thanks for the help here!
Runner

 

Do you have two tanks? If so, does this happen on both? Have you checked the fuel pressure? Even more basic question: have you changed the fuel filter lately?

Assuming the fuel pressure is good, some of your statements lead me to believe it may be fine (finally when it gets warm it stays running), the next set of questions to answer are how old are the plugs, wires, cap and rotor? Is the Check Engine Light on? Have you checked for codes? You can have codes without a CEL on.....

 

Do you have two tanks? If so, does this happen on both? Have you checked the fuel pressure? Even more basic question: have you changed the fuel filter lately?

Assuming the fuel pressure is good, some of your statements lead me to believe it may be fine (finally when it gets warm it stays running), the next set of questions to answer are how old are the plugs, wires, cap and rotor? Is the Check Engine Light on? Have you checked for codes? You can have codes without a CEL on.....

THanks for helping!

I have to tanks. I tested and it does happen on both tanks. I changed the gas filter a few years ago and that should be fine.

Yes, I agree that the fuel pump is probaly OK but I never replaced it. Also it takes a while for the heater guage to get in the middle. It takes a long time to get to that point. I have a new thermostat but never got around to installing However the truck never over heats.

Yes, it stays running when it gets warm. If I try to drive the truck and not let it warm up, it doesn't run smooth.


I replaced the wire about 3 years ago with cap an rotor and plugs. The engine will run steady however, I too believe theres and underlying issues.

About 8 years ago I put on shorty header to make the engine breath better and just last month one of the header gaskets blew and is now leaking and making alot of noise. So I have to replace that,.

The check engine light came on after the gasket blew.

In the past I also replaced the Map sensor,ERG valve,selector valve, replaced all parts in my Front gas tank.

I took a reading last week and were getting these codes. ????? I hate my reader becasue you have to listen to the beeps and sometimes I'll write down the wrong cods. Tomorrow I'll do another reading.

21
24
44
42

Keep in mind that the engine light goes on and off. One of the issues is that I don't use the truck ofter has I should. I just use it for dump runs, plowing snow or picking up heavy loads etc.

thanks for helping.

 

Even though the truck doesn't over heat, you may still need a thermostat. You say it is slow to heat up and then runs fine. The thermostat could be failing to close properly when cold causing a slow warm up.
Hope this helps.

 

Thank you!

Yes, I'll replace the thermostat.

First I'm not going to take my word that the fuel filter was changed a few years ago. I'm going to check to see if that is clogged. If so, I'll replace and test to see if that worked.

Also, i'll check the voltage at the relay etc. I don't have a pressure guage but I think I'm going to get one in time. I'll try and borrow one from a friend.

I"ll keep you posted. thanks for you help.

RUnner

 

Today I replaced the fuel filter. Your were on the mark with the filter being bad. I could NOT remember when the last time I replaced it. I can tell ya it was longer then 2 years ago and I'm afraid to guess. The filterI'd say was 80percent blocked and dirty!

After the filter install, I started the truck and it cranked right over however, when I took it to the end of the my block it ran great!! when I got back to the house, it was bogging down.

I had to keep pumping the pedal and white smoke came out for a few second until I got it came back to normal idle.

I again, tested the front and back tank switch to see if one of the tanks was not working but the test was OK.


I'm guessing its going to take a bit of time to clean out. I think when the engine gets warm it's OK. Those injectors got to be dirty.

I also changed the T-Stat today and I'm letting the RTV dry over night and I'll see how it runs tomorrow. I never changed the T-stat since I had the truck as a 2nd owner.

I don't want to take the chance the truck stalling out on a long drive.

What do you think?

thank you!

Runner

 

In light of the issue happening on both tanks that narrows the cause to a few common components. You have now eliminated the fuel filter. The next on the list is the high pressure fuel pump on the driver side frame rail. You really need to check the fuel pressure. Even though the truck seems to run well when warmed up.

Did you recheck the codes? I do not see any mention of the age/mileage on the plugs, wires, cap, rotor.

 

The wires and plugs were replaced about 3 years ago and look great. The cap and rotor about 6 years ago and don't look too bad. I only put about 150miles or less a year on this truck.

I'll have to borrow the guage from a friend and test the pressure. I might be able to do that this weekend. I'll check the codes tomorrow.

What would cause the white exhaust smoke?


Thanks

Runner

 

White smoke is usually an indication of moisture. Light blue smoke is oil. Black smoke is fuel.

Never trust a 6 year old cap/rotor that is rarely driven.....the aluminum cap terminals on my rarely used 1991 Bobcat 642B (Mitsubishi 1.6L gas engine) corrode faster than you would ever believe. I have not been able to track down a cap/rotor with brass terminals.

Cheap wires can also breakdown over time not necessarily mileage. Never overlook the obvious.

 

Probably moisture then.

I'll look into the Cap and rotor and wires after I check the fuel pressure.

Also, I have to check the ignition timing because I needed to move the distributor out of the way to get to the bottom bolt to remove the T-stat housing.

Hopefully we can narrow the problem down by checking the pressure.

I'm going to pickup the pressure gauge today from a friend and check the fuel pressure and see if it's between 35 to 45 PSI and continue the process of elimination.

thanks for taking the time to help

runner

 

Tested the fuel pressure and I was looking between 35 psi and 45 psi and it was close to 45psi

I'm glad it's not the pump.



I'll do the timing and check the codes tormorrow.
Thank you

Runner

 

Sounds like you either have a bad ECT sensor (two wires) or bad ACT sensor.

 

Can you tell me they stand for and where there these sensors are located so I can test to see if they are bad?

thanks,

Runner

 

ECT = Engine Coolant Temp sensor. Near thermostat with a two wire plug going to it. F-5 in the diagram below.
Go to this link for more information on the ECT sensor:
http://oldfuelinjection.com/index.php?p=28

ACT = Air Charge Temp sensor. Drivers side of intake manifold. C-1 in the diagram below.
Go to this link for more information on the ACT sensor:
http://oldfuelinjection.com/index.php?p=29



/

 

Thank Bill!

Oh.. your referring to why my temp guage and not the fuel issue.

OK. Yes I replaced the ACT in May of 2009 and didn't help however, I never looked at the ECT and I'll bet that might be the reason.

I'll see if there's a way to test it if not I'll replace it.

Yesterday, I replaced the T-stat I'll see if there's a difference.

However, I'm still working on the Fuel issue and hope I can resolve that problem soon.

Your thoughts on that issue.

thanks

Runner