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Topic: Help with hard starting F150 (Read 1665 times) previous topic - next topic

Help with hard starting F150

My Grandpa has this 91 F150 with a 300.  Over the past year it has developed a hard starting problem.  Once the truck starts and warms up it runs like a champ and starts right back up.  As it gets colder it gets harder to start.  This morning it was harder than ever.  If anyone has any ideas please help.  So far we have changed the coolant temperature sensor, fuel pump relay and we have purchased a fuel pressure regulator but havn't installed it yet.  For some reason the scanner for the koeo doesn't work.  I'll have to try the old test light method.  Anyone ever experiance this kinda thing.
One 88

Re: Help with hard starting F150

Reply #1 –
Curse you. That's exactly the kind of truck (minus the hard starting) that I'm looking for. :p

Re: Help with hard starting F150

Reply #2 –
Check your battery and alternator.Take it to Autozone and they can check it for free,and,run codes for free.
'88 Sport--T-5,MGW shifter,Trick Flow R intake,Ed Curtis cam,Trick Flow heads,Scorpion rockers,75mm Accufab t-body,3G,mini starter,Taurus fan,BBK long tube headers,O/R H-Pipe, Flowamaster Super 44's, deep and deeper Cobra R wheels, Mass Air and 24's,8.8 with 3.73's,140 mph speedo,Mach 1 chin spoiler,SN-95 springs,CHE control arms,aluminum drive shaft and a lot more..

Re: Help with hard starting F150

Reply #3 –
Quote from: vinnietbird
Check your battery and alternator.Take it to Autozone and they can check it for free,and,run codes for free.


I'm a Manager at Autozone.    :rollin:  This thing doesn't crank hard at all.  It turns over easily.  Acts more like its not getting gas.
One 88

Re: Help with hard starting F150

Reply #4 –
Attach a fuel pressure gauge to it, start the truck, and let the gauge settle at normal opereating pressure. Shut the truck off and observe the gauge - it should drop, but only slightly. Now leave it alone for a few hours and come back out and check it - if the gauge had dropped significantly you've either got a leaking injector or the check ball in the fuel pump in the tank isn't sealing. Either one would cause a hard start after sitting. A leaking injector would flood the engine, a sticking check ball would make it so that you have to crank the hell out of it to build fuel pressure.

If you end up diagnosing the problem as a bad check valve you can work around it by turning the key to run, then off, then run a few times before you crank the engine - this will help prime the pump and lines. I have to do this with my Dakota if it's been sitting a few days.
2015 Mustang GT Premium - 5.0, 6-speed, Guard Green - too much awesome for one car

1988 5.0 Thunderbird :birdsmily: SOLD SEPT 11 2010: TC front clip/hood ♣ Body & paint completed Oct 2007 ♣ 3.55 TC rear end and front brakes ♣ TC interior ♣ CHE rear control arms (adjustable lowers) ♣ 2001 Bullitt springs ♣ Energy suspension poly busings ♣ Kenne Brown subframe connectors ♣ CWE engine mounts ♣ Thundercat sequential turn signals ♣ Explorer overhead console (temp/compass display) ♣ 2.25" off-road dual exhaust ♣ T-5 transmission swap completed Jan 2009 ♣

Re: Help with hard starting F150

Reply #5 –
Quote
If you end up diagnosing the problem as a bad check valve you can work around it by turning the key to run, then off, then run a few times before you crank the engine - this will help prime the pump and lines. I have to do this with my Dakota if it's been sitting a few days.



I've been trying that forever.  Nothing helps the thing start.  No matter what you do it eventualy begins to fire on 3 or 4 cylinders then acts like they all kick in.  Only takes a matter of seconds to run right but if you put it in gear to soon it goes back to running on 3 or 4 cylinders..    I forgot.  I've tried a fuel filter and changing the coil and I've ran that tfi on the testor at work a thousand times and it doesn't fail.
One 88

Re: Help with hard starting F150

Reply #6 –
I'd be looking at the injectors then...
2015 Mustang GT Premium - 5.0, 6-speed, Guard Green - too much awesome for one car

1988 5.0 Thunderbird :birdsmily: SOLD SEPT 11 2010: TC front clip/hood ♣ Body & paint completed Oct 2007 ♣ 3.55 TC rear end and front brakes ♣ TC interior ♣ CHE rear control arms (adjustable lowers) ♣ 2001 Bullitt springs ♣ Energy suspension poly busings ♣ Kenne Brown subframe connectors ♣ CWE engine mounts ♣ Thundercat sequential turn signals ♣ Explorer overhead console (temp/compass display) ♣ 2.25" off-road dual exhaust ♣ T-5 transmission swap completed Jan 2009 ♣

Re: Help with hard starting F150

Reply #7 –
Man, that sounds like EXACTLY what my tempo does.

Ever since I bought it, it's been tough to start. It always starts, just not easily. If I'm driving the car daily I have to crank it over for several seconds before it fires up. If it's been sitting for a few days, I seriously have to crank it for 15-20 seconds before it starts. And then when it DOES start, it idles rough and sounds like it's running on 2 or 3 cylinders. If you give it some gas it stops sounding like that and smooths out, and from then on it's pretty much fine. I changed the plugs & wires right after I got it but that did exactly squat.

Garrett H.
'94 F250 XLT- 4x4, 5 speed, 7.3 IDI Turbo Diesel, 4" intake, 4" exhaust, 5" turnout stacks, manual hubs, etc.
'87 Thunderbird Turbo Coupe
Engine, wheels, tires, etc!
Exhaust sound clip
Another clip

Re: Help with hard starting F150

Reply #9 –
Quote from: CougarSE
For some reason the scanner for the koeo doesn't work.  I'll have to try the old test light method.  Anyone ever experiance this kinda thing.


I'd be working on that problem. I have a freind that has a '89 t-bird that ran poorly and wouldn't give any codes, turned out to be a bad EEC...

If its not the EEC, likely its a fuel problem, but the "sounds like it's running on 2-3 cylinders" may be the EEC not firing all the injectors(thats a batch fire system, EEC fires three injectors at a time).

Hit it with a good shot of starting fluid before you crank it next time. If it fires off normally then runs poorly awhile(or dies), may not be a bad idea to check the fuel pressure. The pump may be lazy and be slow building pressure. But again with no codes at all being given, my bet is on the EEC. Hell you being mgr, John Nobody can come in and order one. IF it fixes it great.... If not, John never showed up to get it...

Also you changed the EEC temp sender and not the gage sender....right??

Re: Help with hard starting F150

Reply #10 –
Hmm thanks for the tip on the eec thing.  Didn't know that.  the scanner never even beeps on the truck. 

The pump does seem lazy but the truck doesn't do it later in the day after its been run for a while.  even if it sets for like 10 hours after running for one hour. 

Yea I know the differnce between the two coolant sensors.
One 88

Re: Help with hard starting F150

Reply #11 –
The EEC may have some borderline components and not like being cold. You could hit it with a heat gun or hair dryer, for a few minutes to see if it will start normally when everything else is still cold.

Re: Help with hard starting F150

Reply #12 –
Hmmm, that makes sense...

Last winter, I had to start my tempo one day when it was about 0 outside. I had to crank it for so long that the battery almost went dead, then it finally fired up and ran like  for several minutes before finally smoothing out.

Garrett H.
'94 F250 XLT- 4x4, 5 speed, 7.3 IDI Turbo Diesel, 4" intake, 4" exhaust, 5" turnout stacks, manual hubs, etc.
'87 Thunderbird Turbo Coupe
Engine, wheels, tires, etc!
Exhaust sound clip
Another clip
 

Re: Help with hard starting F150

Reply #13 –
All of this and I forgot the old time computer tests!  I'll try warming it up tomorrow.  Then I'll freeze it to see if it starts hard.  If its the computer I'm sure I can find a bone yard one easily.  Thanks turbocoupe!
One 88