no-start problem

[surveyboy]

well this isn't related to the 4x4 system of the truck, but, i'm hoping someone knows an answer.

'93 f150 with I6 engine.

ran great. started it up saturday, drive < 1 mile, shut off, would not re-start.

at first, it didn't seem like the fuel pump was clicking on. after it sat for a bit, it'll start for a second and shut off. and now the fuel pump runs constantly on either tank (2 seperate pumps, 1 in each tank) where as before, it would run, pressurize and shut off.

one tank is 1/4 full, other is full.

thoughts??

fuel filter? bypass valve? flooding the motor??

I haven't pulled the fuel line to see if there is fuel coming thru the lines yet.


update at post 60

[welndmn]

You have a schreader valve on fuel rail, just press it down, it should have 40PSI of pressure so it should be enough to squirt you in the eye.

Really the other common things on those that fail are EEC relays, so check for spark.

[surveyboy]

Originally Posted by welndmn

You have a schreader valve on fuel rail, just press it down, it should have 40PSI of pressure so it should be enough to squirt you in the eye.

Really the other common things on those that fail are EEC relays, so check for spark.

ahh, will do.

and would the EEC relay be interminit? after it sits for a few, it'll start, running really rough for 3-5 seconds then die again.

[EarlKann]

This is just the trucks way of asking to go peacefully to it's grave.

[f250rollinon37s]

the pump will run for 2 sec to prime the system, then off untill the engine starts, or you turn it off and cycle the key

if its running and it the truck wont fire off eather tank - i dbout it a pump

have someone crank her and check for spark

the TFI modules are known for failing - it controls the spark and the injector base firing

if it runs and the pumps never shut off the EEC relay can crap out

[Danger Ranger]

check the stupid shit first... see if you have fuel and spark.

We had the same truck, one day it started stripping dist gears left and right... I hated that damn truck.

[surveyboy]

Originally Posted by EarlKann

This is just the trucks way of asking to go peacefully to it's grave.

LOL, I haven't recouped my $$ from getting the tranny fixed yet. i can't let it die LOL

Originally Posted by f250rollinon37s

the pump will run for 2 sec to prime the system, then off untill the engine starts, or you turn it off and cycle the key

if its running and it the truck wont fire off eather tank - i dbout it a pump

have someone crank her and check for spark

the TFI modules are known for failing - it controls the spark and the injector base firing

if it runs and the pumps never shut off the EEC relay can crap out

correct, until this happened, it was always like that.

it sometimes runs rough for 2-3 seconds then dies and the pump never shuts off. so i know its getting spark... at least sometimes.

TFI and EEC seem to be lead contenders here. Napa items or dealer items?

Originally Posted by Danger Ranger

check the stupid shit first... see if you have fuel and spark.

We had the same truck, one day it started stripping dist gears left and right... I hated that damn truck.

knock on wood, this truck has done me good first time it left me on the side of the road.... caught fire once in the garage.. but always made it home LOL.... i'll actually check to make sure dist is tight too.


thanks guys

[f250rollinon37s]

napa has them both - they can test the TFI ( well some locations can )

but i have had them test good and still be failing ( aka i didnt beleive the napa guy and put a new one on and it ran fine )

check the ecm grounds on the fender, and the engine grounds - a bad connection can do wonders

[4XFORD]

Originally Posted by surveyboy

LOL, I haven't recouped my $$ from getting the tranny fixed yet. i can't let it die LOL

Yeah, I hear ya. Besides that, isn't Ford out of business??

Originally Posted by surveyboy

it sometimes runs rough for 2-3 seconds then dies and the pump never shuts off. so i know its getting spark... at least sometimes.

Sure sounds like a pump but with two tanks....no way.

Originally Posted by f250rollinon37s

napa has them both - they can test the TFI ( well some locations can )

but i have had them test good and still be failing ( aka i didnt beleive the napa guy and put a new one on and it ran fine )

Don't blame them, thermal distortion has a lot to do with electronic components. Once they're hot they fubar.

[surveyboy]

Originally Posted by 4XFORD

Yeah, I hear ya. Besides that, isn't Ford out of business??




Sure sounds like a pump but with two tanks....no way.



Don't blame them, thermal distortion has a lot to do with electronic components. Once they're hot they fubar.

ok, update on last night.

I checked spark getting from the coil to dist, check
spark from dist to plugs, check
schreader valve found and fuel in the line, check (although i just let a little bit out, would an air somewhere in the line cause something like this?)

still doesn't start and either fuel pump runs continuously (ie, neither builds up pressure and shuts off)

I haven't verified if its firing at the right times (ie, dist jumped a tooth) spark seems pretty good.

where would i find the TFI and EEC modules on the truck?

[welndmn]

How much fuel came out when you hit the schearder valve?
Cycle the key to build up pressue, then hit the valve. 40 PSI is what it should be.

[surveyboy]

Originally Posted by welndmn

How much fuel came out when you hit the schearder valve?
Cycle the key to build up pressue, then hit the valve. 40 PSI is what it should be.

dunno, i just pushed the valve open and got gas on my hands

I didn't spray much of it to really get a feel for the pressure, but it didn't feel like a pressure washer nozzle just hit me.


do they have gauges for that? I'm assuming a tire gauge wouldn't work LOL

[4XFORD]

http://www.northerntool.com/webapp/w...9231_200329231

[welndmn]

40 PSI should jump up about a foot.
I just wanted to make sure it did not just dribble out.

[surveyboy]

Originally Posted by welndmn

40 PSI should jump up about a foot.
I just wanted to make sure it did not just dribble out.

I'll check it again tonight.

[surveyboy]

ok, checked last night. Seems to have decent pressure spraying out of the valve when the key is on, you can hear the fuel running thru the lines

if i cycle the key on and off 3-4 times real quick, it'll sound like it trys to start.. but wont

[JGVABronco78]

Originally Posted by surveyboy

you can hear the fuel running thru the lines

We need to be clear here. It sounds like you said neither pump builds pressure and shuts off. Is that with just the key on and engine not running? The pump should build pressure quickly and shut off if the engine is not running.

Now you are saying you can here the fuel running through the line. Is this with the engine off? If either of these are with the engine off, I'd say the fuel pressure regulator is shot. If its with it running, then maybe its still bad. You need to check the pressure with a gage probably either way.

The fuel pressure regulator should be at the end of the fuel rail where the return line connects and heads back to the tank(s). I believe it only has a vacuum line to it, but it may have a vacuum line and an electric plug.

[surveyboy]

ok.

the pump is not building pressure and shutting off when the engine isn't running.

with the engine off, the pump continously runs and i can hear the fuel running thru the system in the engine compartment

I recal seeing something at the back of the motor on the fuel rail.

[surveyboy]

ok, got a pressure gauge on the fuel line.

60psi.

still doesn't start, and the fuel pumps run all the time.


we sprayed some carb cleaner in the intake and it fired up, so the spark is there and working.

so, what do you guys think? fuel pressure regulator? other?

[JGVABronco78]

60 sounds like a lot, maybe too much? Could there be a safety switch that keeps the injectors from stroking if the pressure is too high. If 40 is normal, what is considered too high?

[surveyboy]

I was thinking that the high pressure was not allowing the fuel to get to the injectors or the unit that fires off the injectors is shutting them off or not working. (although if the injectors weren't working, i'd think the fuel pump would shut off normally after it pressurizs)

[welndmn]

When are you home? Maybe I need an excuse for a drive to help you make it run
If you have pressure, and you have spark, and we assume you have timing, then it should run.
Spraying either/carb cleaner, down the throttle body, did make it run, to me means you have a flow issue with fuel.
Having 60 psi in that system to me means something is fuct' either the pump (that only shoots 40 psi) is running way hot, or your pressure regulator is hosed.

Do you have a vaccum pump? putting 10-15 inches of vaccum on the Reg, and checking the pressure again. Adding vaccum should make a change in the pressue.

[JGVABronco78]

I on uncharted territory here, but it seems like the high fuel pressure, pump running on and injectors not squirting are related to one malfunctioning part, most likely a pump pressure cut-off switch. The injectors not squirting is a safety feature to cause you to investgate the problem??? Just a guess. Its either that or a malfunctioning FPR, and the injectors can't physically overcome the high pressure, or are designed not to.

[surveyboy]

Originally Posted by welndmn

When are you home? Maybe I need an excuse for a drive to help you make it run
If you have pressure, and you have spark, and we assume you have timing, then it should run.
Spraying either/crab cleaner, down the throttle body, did make it run, to me means you have a flow issue with fuel.
Having 60 psi in that system to me means something is fuct' either the pump (that only shoots 40 psi) is running way hot, or your pressure regulator is hosed.

Do you have a vaccum pump? putting 10-15 inches of vaccum on the Reg, and checking the pressure again. Adding vaccum should make a change in the pressue.

any day during the week after 5 and all weekend

don't have a vacume pump anymore.

if the pressure regulator is what also makes the fuel pumps turn off, then that sound like a possiblity.

could there be some other elec. issue causing the pumps to run 'hot' and not allowing them to shut off? ie, an elect. short somewhere?

[JGVABronco78]

I've seen a Ford truck electric pump run on even with the key off, so yes a short could be the problem. The injectors may be sensitive too excessive pressure by design. Is there a relay that controls the pumps in the box. Try switching it with a like relay that won't effect start up. They may have improved the system so that the output of the fuel pump relay has to go through the ignition switch also in case it does get stuck closed.