Replying To gbs F150 No start Post Jinks me Today

1988 F150 5.0 EFI drives up to the door today she said it was all she could do to get it to the shop it ran like chit she had to baby the throttle to get it to run with out knocking off. It happen all of a sudden...

She shut it off at my door it would not restart... But that's the way we like'em... Cranks but wont start battery and voltage are normal while cranking and cranking RPM are normal were would you start your diagnosis.

Check fuel pressure. Pump may be failing.

Diagnosis should start with some basic checks. First, check for spark. Next check for fuel pressure. If both are good, compression check comes next. Since it will not start, by the time these checks are made, you have probably found the problem. If not, then it is time to check for codes. Since this is not an OBDII model, you will need a STAR tester or equivalent to check the codes. Run the KOEO test for hard codes, and any longer term codes in memory. 11-10-11 would indicate no hard faults. There are a few failures that would prevent it from starting. A failed TP sensor could put the PCM into "clear flood" mode, which would turn off the injectors. 88 model should use a B/MAP sensor. That could also cause a no start. Both items would set a code.

(quoted from post at 09:02:19 02/08/18) Diagnosis should start with some basic checks. First, check for spark. Next check for fuel pressure. If both are good, compression check comes next. Since it will not start, by the time these checks are made, you have probably found the problem. If not, then it is time to check for codes. Since this is not an OBDII model, you will need a STAR tester or equivalent to check the codes. Run the KOEO test for hard codes, and any longer term codes in memory. 11-10-11 would indicate no hard faults. There are a few failures that would prevent it from starting. A failed TP sensor could put the PCM into "clear flood" mode, which would turn off the injectors. 88 model should use a B/MAP sensor. That could also cause a no start. Both items would set a code.

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You were doing good till you got to "Since it will not start, by the time these checks are made" No star tester needed BTW... That's why I like these NO SCAN DATA fords you had to be the hunter... You did not have a data menu that dumbs down folks....

I did not see were you verified spark so how would you do it...

Later but not were you would start... Try again...

You did hook up your coil checker to see how much spark gap it put out, didn't you?

Check ignition switch our ford mechanic replaced a lot of them.

Apparently you did not read through my post. By the time you would get to the STAR tester, you would have most likely found the problem. A STAR test does make diagnosis easier if you reach that point.

Spark, fuel, timing/compression.

This is the most logical course to take. Compression check, I assume, would be to see if the timing chain skipped but it would be easier just to do a timing light check.

When one of those heaps comes to my shop, no
matter what it is doing, in my neck of the
woods, I check the spring towers and the
frame behind the cab for rust out as my
first diagnostic step. I won't touch them
if the customer is going to have to spend
money on a truck that is going to have a
mortal failure in a couple of months. I
have sent a few to the crusher this way
rather than spend hours of diag on a $200
truck. Chevy trucks of that vintage are
getting almost as bad, have condemned a
couple of them for frame rot also. Doesn't
break my heart to not get the business of
working on an injected 5.0, 5.8, or 7.5
engine, the most overcomplicated, hard to
diag fuel injection system of the Big 3 at
the time.

(quoted from post at 10:17:59 02/08/18) Apparently you did not read through my post. By the time you would get to the STAR tester, you would have most likely found the problem. A STAR test does make diagnosis easier if you reach that point.

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No Star tester needed even if I did use a scan tool it would have been a no code issue as it would be on most all fords of this vintage are even every vehicle to date including a tractor new are old...

OK you nailed #1) Check Spark and #2) fuel pressure and now off track.

I hope you verified spark with a adjustable spark checker are a spark checker made for this ignition system. I hope you did not use your best guess by holding the coil wire close to ground are a screwdriver. We need verifiable information not your best guess. We want to be one and done with #1 a spark check, its the first question that needs a answer. This holds true for a Tractor also.
When someone post I have a no start I have a good battery and cranks normal battery voltage and cranking RPM are normal. I have checked spark its good what do I need to check next is were the wheels fall off and they are lead down the wrong track.

The first question should be How did you check spark, That question needs to be verified ! (Not your best guess)

Second question were did you check for spark. I hope you do this in a order that will confirm the travel path spark takes we want to be once and done and move on.

Answer: Remove the coil wire at the distributor cap install a spark checker if a GO remove a spark plug wire at a spark plug install a spark checker if a go move on.

Next check fuel in this case fuel pressure is normal and fuel quality is good. We have a GO.. This one does throw a curve ball it has dual fuel tanks you can switch tanks to see if its a start after you prime the fuel system. What are the chances both pumps went out at the same time. I say next to none but have seen it happen when the system is that contaminated.

WE have VERIFIED. (not our best guess)

1) battery/battery voltage cranking
2) cranking RPM ( I am going to trust your sense of normal)
3) Spark
4) fuel
All hold true for a tractor next we are moving on to a non related tractor test.

Question: whats the next test, Its not install a scan tool remember this vehicle does not offer a scan data menu to order from we are on our own a hunt we have to gather the information for our-self. Even if we had the latest greatest scan tool we don't need it at this point. Ell we don't even need youtube .

Whats the next test.

Sprint 6 we have a all in customer we have a old nice F150 and believe me its been a nightmare. It has 105K on the clock. It has more new parts on it that the law allows.

The customer has blessed it with her pocket book

ok if your an experenced mechanic you have a feel for whats wrong by what you hear is it cranking fast enough, do you hear the fuel pump come on when key is turned if it dont it not goina run if it does check spark , fuel pressure, timing chanes jump when thay are shut off, have changer lots of furl fuel pumps, crontrol moduls timing chanes aswell but you might get lucky and it needs a fuel filter.

If it is one of my old F-150's it has a 300 /6 cylinder. There is no timing chain.

At 105k it is just getting broke in.Time for me to buy it.

(quoted from post at 21:48:39 02/07/18) 1988 F150 5.0 EFI drives up to the door today she said it was all she could do to get it to the shop it ran like chit she had to baby the throttle to get it to run with out knocking off. It happen all of a sudden...

She shut it off at my door it would not restart... But that's the way we like'em... Cranks but wont start battery and voltage are normal while cranking and cranking RPM are normal were would you start your diagnosis.

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Quick and dirty, I would first have a quick look to make sure somebody had not taken a pressure washer to it and soaked down the ignition.

Pop the cap off for a quick look to make sure the rotor and or pin in the cap has not burned through.

1988 I think had a low pressure pump in each tank and a high pressure pump on the frame.

Pull the hose off the fuel pressure regulator and hook up an injector flush can with gas in it to the Schrader valve, if it still does not run with external fuel pressure then time to push it into the shop. And start with the basics.
Air ?nest in filter
Fuel and proper fuel (not 1/2 diesel)
Spark first would be plug in a spare TFI module for a quick test
Compression should be properly checked but likely you can for now rule that out by listening to it crank.

"Whats the next test."

We have fuel pressure, but are the injectors firing, or flooding?

Sniff the exhaust for raw gas. If no smell, give it a squirt of gas in the throttle body, see if I can make it run.

(quoted from post at 19:30:11 02/08/18)

(quoted from post at 10:17:59 02/08/18) Apparently you did not read through my post. By the time you would get to the STAR tester, you would have most likely found the problem. A STAR test does make diagnosis easier if you reach that point.

Click to expand...

No Star tester needed even if I did use a scan tool it would have been a no code issue as it would be on most all fords of this vintage are even every vehicle to date including a tractor new are old...

OK you nailed #1) Check Spark and #2) fuel pressure and now off track.

I hope you verified spark with a adjustable spark checker are a spark checker made for this ignition system. I hope you did not use your best guess by holding the coil wire close to ground are a screwdriver. We need verifiable information not your best guess. We want to be one and done with #1 a spark check, its the first question that needs a answer. This holds true for a Tractor also.
When someone post I have a no start I have a good battery and cranks normal battery voltage and cranking RPM are normal. I have checked spark its good what do I need to check next is were the wheels fall off and they are lead down the wrong track.

The first question should be How did you check spark, That question needs to be verified ! (Not your best guess)

Second question were did you check for spark. I hope you do this in a order that will confirm the travel path spark takes we want to be once and done and move on.

Answer: Remove the coil wire at the distributor cap install a spark checker if a GO remove a spark plug wire at a spark plug install a spark checker if a go move on.

Next check fuel in this case fuel pressure is normal and fuel quality is good. We have a GO.. This one does throw a curve ball it has dual fuel tanks you can switch tanks to see if its a start after you prime the fuel system. What are the chances both pumps went out at the same time. I say next to none but have seen it happen when the system is that contaminated.

WE have VERIFIED. (not our best guess)

1) battery/battery voltage cranking
2) cranking RPM ( I am going to trust your sense of normal)
3) Spark
4) fuel
All hold true for a tractor next we are moving on to a non related tractor test.

Question: whats the next test, Its not install a scan tool remember this vehicle does not offer a scan data menu to order from we are on our own a hunt we have to gather the information for our-self. Even if we had the latest greatest scan tool we don't need it at this point. Ell we don't even need youtube .

Whats the next test.

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This is not a guess test I have provided information its verified.

WE have VERIFIED. (not our best guess)
WE have VERIFIED. (not our best guess)

1) battery/battery voltage cranking
2) cranking RPM ( I am going to trust your sense of normal)
3) Spark (with a spark checker)
4) fuel (in speck)

Test 1,2,3,4 are a go not problem with 1,2,3,4

Whats the next test.

(quoted from post at 22:05:45 02/08/18) "Whats the next test."

We have fuel pressure, but are the injectors firing, or flooding?

Sniff the exhaust for raw gas. If no smell, give it a squirt of gas in the throttle body, see if I can make it run.

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We have a winner to the next test #5...

WE have VERIFIED. (not our best guess)

1) battery/battery voltage cranking
2) cranking RPM ( I am going to trust your sense of normal)
3) Spark (with a spark checker)
4) fuel (in speck)



We have fuel pressure, but are the injectors firing, or flooding.

WE have VERIFIED. (not our best guess)

1) battery/battery voltage cranking
2) cranking RPM ( I am going to trust your sense of normal)
3) Spark (with a spark checker)
4) fuel (in speck)
5) fuel injector pluse

How do I test #5 fast and EZ what tool do I need and what can that tool tell me.

Air flow both intake and exhaust

Collapsed hose?
Blocked or plugged filter, ice, dirt, nest etc?

Crushed exhaust pipe, melted converter, potato, rag or other in tailpipe?

Although you can usually feel the injector clicking with the tip of your finger a Noid light would be the proper tool to use.

ignition module
coil
ingition switch

I have a 89 and it trashes modules so bad I keep one in glove box. Plus it is hard to even get a good one.

Check the coil for being shorted and buy a Motor Craft module.

(quoted from post at 23:43:11 02/08/18) Although you can usually feel the injector clicking with the tip of your finger a Noid light would be the proper tool to use.

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We have a winner yes a Noil/Noid (close enoufh for me) light... This is were it get interesting it blinks as it should if all you are looking for is a blink. The noid light is on the dim side so I disconnect the coolant temp sensor expecting the injector pulse to be longer and a brighter light but no change I disconect the TPS no change..

WE have VERIFIED. (not our best guess)

1) battery/battery voltage cranking
2) cranking RPM ( I am going to trust your sense of normal)
3) Spark (with a spark checker)
4) fuel (in spec)
5) fuel injector pluse

What should my next step be (tip its not wild and crazy) all systems that have been tested are "VERIFIED" GOOD but after this test we are gonna do some serious hunt'N. (remember no scan data) Re read if you are guessing compression, fuel, spark, ignition, ignition switch, voltage, starter, stay on the path 1 thu 5 have been ruled out... VERIFIED...

What should my next step be :?:

If the noid light isn?t bright you need to check
voltage to the injectors. 12v+ is supplied by the eec
relay and the ground is supplied by the pcm. You
didn?t mention checking battery voltage at the
injectors.

No I did not I had not confirmed why I had a no start checking voltage at the injector was in the back of my head tho :wink: My thoughts why did the light stay dim when I tried to drive the system pig rich to get a long bright light/pluse.

I am satisfied that

1) battery/battery voltage cranking GOOD

2) cranking RPM ( I am going to trust your sense of normal) GOOD

3) Spark (with a spark checker) GOOD to spark plug

4) fuel pressure (in spec) GOOD

5) fuel injector pluse (GOOD but not liking the dim pluse)

I know I have 4 of the five things needed for a engine to run

5 Things an Engine Needs in order to Run

Air

Spark

Fuel – fuel pressure and fuel injector pulse

Compression

Timing – All of the above at the right time



The next test will prove the engine will run and send me looking for the cause of a dim pluse what is this simple test... TIP I have not proven I have one of these...

Fuel – fuel pressure and fuel injector pulse

Its not "fuel pressure and fuel injector pulse" what test can I preform to prove what I need for the engine to run. I can take all the injectors throw them away and plug the holes what do I need to add/induce to prove the engine will run. This holds true for your tractor also you don't need a carburetor to prove the engine will run to keep it tractor related...

Blow some propane into the intake.

While doing what I think you are going to do next.
Do it with caution and leave the air filter box open.
I have seen quite a few plastic air boxes destroyed when a backfire ignites the either in the intake and ducting.

(quoted from post at 10:47:14 02/09/18) Blow some propane into the intake.

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We Have a winner will get back to it later got lots of road to cover today.

Been a long day...

Yes add fuel are in some cases take fuel away in this case add fuel it was under fueling.

I gave it a big shot of brake cleaner directly into the throttle body it hit but did not start but acted like it wanted to. That’s my sign so hit it again with BK and let if set about 30 sec to let the BK vaporize when I hit the starter if fired right off and idled like a new one.

Let’s stop hear and talk about what just happened what can be learned. The big question is what do I know at this point what have I confirmed and where do I go next. Let’s scratch off what’s known good. Its under fueling at start up and under fueling at anytime other than at idle...

The truck was 50ft from the door it was starting to rain I wanted it close to a shop door I was waiting for a clear bay to get it inside. I pulled it up to a door if I gave it any throttle it wanted to stall it idled up to the door and idled normal in fact I let it idle for 30 minutes it idled just like a new truck.

5 Things an Engine Needs in order to Run
Air
Spark
Fuel – fuel pressure and fuel injector pulse
Compression
Timing – All of the above at the right time

Fuel is still the prime suspect it’s the only thing I have added I need to find out why it’s under fueling. I don’t need to chase my tail with off the wall chit that has nothing to do with why it’s under fueling. Break out box connected I start my search I don’t need a break out box I have two so hook’er up. I pull out my notes from many of the Fords I have done in the past you don’t see many of these non-data menu ford any more so I cannot rattle off what pins I need to check.

I pull it in the shop shut if off and try to start it guess whut I have a no start again. Just the way I like'em...

Break out box hooked up I check coolant temp voltage its .61V, .60 shows around 194 degs GOOD

I check ACT (air charge temp) .75V 174 deg. GOOD

I am headed next toward checking TPS (throttle position sensor) I look at my notes and MAP (manifold Absolut presser sensor) is just under TPS pin voltage check a light goes off in my head check MAP next. Map is the easiest of the bunch no break out box needed but a break out box is hooked up.

Normal readings, barometric pressure plays a roll these are normal for my elevation.

KOEO (key on engine off) 158HZ
KOER (key on engine run at idle) 114 HZ.

Lets see what the MAP reads.

I am in KOEO state I read 125 HZ WTF engine is off I am getting an at idle reading it should read 158HZ no wonder it idles so well once I get it up and running. MAP sensor is stuck at 125 KOEO, KOER. That explains why it stubbles when I give it throttle the MAP is your accelerator pump if it were a carburetor engine are plays well into the fuel strategy. The MAP sensor is new my guess 1 ½ years old by what she tells me this truck has more new parts on it than the law allows down to new fuel tanks…


So why take the time to post this. I hope folks stop and take the time to verify whats good with a few simple test with tools made to do the test with a 100% kill rate not some billy bob trick that is not 100% acturate, take the time to read the info provided take the time to ask for more information.

Keep it simple even on your tractor

5 Things an Engine Needs in order to Run
1)Air
2)Spark
3)Fuel – fuel pressure and fuel injector pulse
4)Compression
5)Timing – All of the above at the right time

In the case of spark and fuel you can make your own making spark is not as EZ tho... Before someone jumps me about air its not a given, air is so much a part of engine control management today it has a sensor to measured air flow in grams....

I sure do miss these NO scan data Fords they made you a better man you were not dumbed down and overwhelmed with information you had to go look for it.... The bad, on my end good information was hard to come by information providers sent you on a witch hunt with a OHM meter you could ohm till ell froze over and never fix it... It would have been nice if they would just tell you what the puter was looking for and that was the return VOLTAGE from the sensor. I have yet to see a puter look for the ohm reading :evil:


One more thang many years ago I had one that I faught off and on for a year it ended up being the vacuum line to the map sensor was sucking together intermittently.

Long ago & far away from better equipment, I improvised and put a cig pack size transistor radio next to MAP and could hear the frequency changes. Just a recollection.

Seems to me that I mentioned the MAP sensor a while back.
You say no scan tool needed, but a scan tool would have pointed you to the MAP sensor. This proves that there is more than one way to find a problem.
I might mention that a MAP sensor tester is an electronic diagnostic tool just as much as a STAR tester is. Just an alternate to using a scan tool.

You put the cart in front of the horse and did not answer the question... I was not looking for a silver bullet I was looking for solving the questions that would lead folks to a silver bullet... Most everyone of those questions apply to yer tractor...

BTW no scanner/star tester needed can you tell me how I can use a scanner/star tester to diagnosing my old ford tractor.

(quoted from post at 07:36:11 02/10/18) Long ago & far away from better equipment, I improvised and put a cig pack size transistor radio next to MAP and could hear the frequency changes. Just a recollection.

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I remember that it may have applied here but I have never seen it apply on all the other map sensor problems I have ran across... I like using all my 5 senses but find it hard to hear the difference tween 114HZ and 158HZ...

For the time it will take I would be pulling the ECM and be doing a smell test on the capacitors.
Is there a fuel pump running non stop by chance?

They did not by chance fill it up with Diesel?

Don't you think I would have caught the pumps ruining all the time.. Now I never look forward to pulling the ECM they can be a real fight to get back in the hole and sealed up ....

Don't look like smell like are taste like diesel to me... Yes I take a sample and test the fuel when I have a drivabilty issue... You can not beat one of these bottles to run a sample in...

For what it was worth I threw it in as a possibility.
I am more of a GM guy, a little rusty on the Fords.

Most come out and in EZ most go back in EZ if you get a hold of one the seal fights you you are in for a fight you will not forget, they fit thru the fire wall lower left...

I have took the ecm out ran my break out box thru the hole so I could drive it and scope off the break out box... You are in deep chit if you have to go that far...