Truck dies while driving

[Nelson674]

This is gonna be a bit long winded but I'm gonna try and get all the details. Hopefully answer the questions before they are asked.


First off, What we're working with.

1990 Ranger 4x4 2.9 Automatic
about 170K on the odo

Purchased the truck in June of 2010. Took it home and and did a tune up. Replaced the cap and rotor, wires, plugs, air filter, oil, ect.. I also bought a fuel filter but somehow forgot to install it. Lift and new tires around last February.

Truck has always ran ok. Sticky lifter issues, truck doesn't like to go much faster then 60, or climb hills at highway speed (this is when you really hear the lifter/s) That and the truck jerks when I put it into drive from park or from drive to reverse. (normal? probably not?)

Driving home from work the other night, I pulled onto the road and got about 100 yards and out of the corner of my eye I saw the tach twitch. At the same time the gas pedal got "soft" for a half a second. Then again about a mile or 2 later, climbing a short but steep hill (35mph), I noticed it again. It dropped about 1k and then recovered. Ran fine until I was almost home (15miles). I guess the engine just died. The gas pedal got soft and had no response, tach dropped to 0, lights went dim, check engine and battery light came on, rolled up the incline I was on and pulled onto a side road where I lost power steering. The engine was definitely dead at that point. Put it in park, tried to start it, no go. Let it sit for a minute , turned the key again, fired right up and drove home ( another mile).

Talked to my brother and he thought it might be a fuel problem. Dug out that fuel filter I bought a year ago and installed it today hoping it would solve the problem. (old one clogged?) Took it out for a drive and had a very similar experience as last night.

Left my house, got about 5 miles and saw the tach drop and recover just like it did last night. Turned around and started heading back home. Got about a mile down the road and it died just like it did before. Again I tried to start it right away, the engine turned over and revved up like it was going to start but the tach dropped back to 0, engine dead. Waited for a minute or so, turned the key, engine starts, drove back home.

I'm pretty sure I hear the fuel pump kick on when I turn the key to "on". And there was a good amount of fuel that came out of the old filter when I took it off.

My brother suggested that the alternator belt might be slipping or something..
I did break a belt 2 months ago and my dad replaced them all for me while I was at work. I checked the tension and they didn't seem loose too me but I don't know exactly how tight it should be. Maybe when the truck warms up they get loose?


You guys have any other ideas???

Injectors maybe?

something electrical?

I saw someone mention a TFI module in a similar thread?

This is my DD so I need to get this old girl back on the road!


Thanks in advance for any help

Nelson

 

[TimR]

test pressure at fuel rail

 

[modelageek]

test pressure at fuel rail

I agree with Tim^^^^^^^^^^^^^ do all the tests, koeo, koer, koer and pull the vacuum line..........see how long the fuel pressure last after you turn the truck off.......

 

[Nelson674]

thanks for the suggestions guys.

I don't have a fuel pressure test gauge but I saw in another thread someone suggested just pushing the valve with a screwdriver to see if fuel is up in the rail.

I did this with the ignition off and (obviously) the engine off. Fuel squirted out (not just a dribble) when I depressed the valve. So I guess the fuel is making it to the rail and holding pressure.

My brother did some reading last night and he seemed pretty convinced that it could be the TFI module.


There is a Napa parts store close to my house, should I go buy a fuel pressure test gauge?

 

[RyanL]

thanks for the suggestions guys.

I don't have a fuel pressure test gauge but I saw in another thread someone suggested just pushing the valve with a screwdriver to see if fuel is up in the rail.

I did this with the ignition off and (obviously) the engine off. Fuel squirted out (not just a dribble) when I depressed the valve. So I guess the fuel is making it to the rail and holding pressure.

My brother did some reading last night and he seemed pretty convinced that it could be the TFI module.


There is a Napa parts store close to my house, should I go buy a fuel pressure test gauge?

Good luck with finding a fuel pressure gauge at your local parts store. When I went to the local Napa around where I live, all they had was an old style fuel pressure tester (goes up to something like 15PSI). Another local parts store had one for close to $200. I checked around (even on the internet) and I couldn't find one worth buying for the price I was willing to pay. I even rented one from Autozone but it was useless because out of the 56 parts it had in the kit, none of them fit my fuel rail. I ended up buying one with at a Salvo parts store for $40. It was cheap because it only had 2 fittings, but one of them was the right one. But before you jump to any conclusions, check your engine codes first. It's free and easy to do. All you need is a little jumper wire and watch and count the check engine light flashes.

 

[freedom5]

Fuel Pressure Guage

I found a Fuel Pressure Guage Kit with all the adapters for different vehicles at Harbo Freight & Tools for about $20.00 (as well as I remember). I have used it and it works fine. Be sure you wrap the threds with teflon tape on the adapter that screws into the guage. Also I also found a unique set of box end/open end wrenchs going up to 1" for $19.95. The y are designed so each wrench will work on bothe metric and sae bolts and fittings. They have been invaluable for changing the O2 sensor and the manafold air sensor plus other things so you don't have to empty your tool box while working on the vehicle.

freedom5

 

[Nelson674]

Got the harbor freight fuel pressure test gauge. $20.00

KoEo hit 35 then dropped to 29 and held it

KoEr 31 constant

Turned the engine off and it slowly rose from 31 to 34 and held it

It seems as if the engine runs just fine until it gets warm/hot.

I ran it in neutral in the driveway until it died. Started back up and noticed that the tach was twitching all over the place but the engine rpm sounded the same.

Its got to be the TFI?? Alldata says that the TFI "controls" the tach(as well as other things).

Can someone send me a link to how to check the engine codes with the jumper wire or whatever?

I guess ill do that before i start tearing everything apart..

 

[Nelson674]

Self test results (jumper wire from "self test in" to "signal return")

This is with Key on Engine off (O)
(M) is memory code but I'm not sure I saw any memory codes. there wasn't a 6 second pause/flash/6 second pause between the codes ( 18 and 95 ). however the tach was erratic intermittently..

18 (R) Check base timing & advance function - Timing Tests
(M) Ignition TACH signal erratic - Ignition Systems

95 (O) Fuel pump: open, bad ground or always on - Power / Fuel Pump Circuits
(R) AIR not Diverting (AIRD) - Air Injection
(M) Possible bad fuel pump ground or open between fuel pump and pin 8 at PCM (Fuel Pump Monitor signal) - Power / Fuel Pump Circuits

Could the code 95 be a result of unplugging the inertia switch (removing power from the fuel pump) and turning the engine over to relieve the fuel pressure before hooking up the fuel pressure test gauge?

I ask because when the truck dies, it dies. It doesn't sputter out like its using up the fuel that is left in the line. It just dies instantly. If the pump shut off wouldn't the engine sputter until the residual pressure/fuel in the line ran out?

 

[TimR]

no, it takes pressure to fire the injectors.

 

[RyanL]

no, it takes pressure to fire the injectors.

Well pull the fuse to the fuel pump while it's running. It just doesn't die. It will run for a few seconds and slowly die just like dude is suggesting.

 

[Nelson674]

Hooked the fuel pressure gauge back up and ran the truck till it died. Pressure never dropped below 30 and was sitting at 40 after it died.

I would think that means everything in the fuel system from the rail back is good?

Eventually the truck just would no longer start. It would turn over, spark tester on the plug and on the coil both showed spark.

To see if unplugging the inertia switch was the cause of the code 95 I did the following. Cleared the codes, Turned the engine over a few times to see if it would pick up the same codes as before. Honestly, I'm not sure what I got when I checked the codes again. It definitely was not the same as before. Not sure what it was though. It kinda seemed like it was just a constant even flash (on/off/on/off...)???

So I finally got the TFI module off the distributor (was able to take it off without removing the distributor.) and did the resistance check described in this link. (test #5, almost at the bottom of the page) http://www.therangerstation.com/tech_library/TFI_Diagnostic.html

The first on the list "a. - GND-PIP IN: should be greater than 60 ohms."
returned no reading at all on my digital ohmsmeter. Checked it against a cheap analog ohmsmeter and same thing, no reading. All other checks returned good readings.


1 - Remove the TFI from the distributor or the front fender apron.

2 - Measure the resistance between the TFI terminals as shown below:

a. - GND-PIP IN: should be greater than 60 ohms.

b. - PIP PWR-PIP IN: should be less than 2,000 ohms.

c. - PIP PWR-TFI PWR: should be less than 200 ohms.

d. - GND-IGN GND: should be less than 2 ohms.

e. - PIP IN-PIP: should be less than 200 ohms.

3 - If any of these checks failed, replace the TFI with a new one.


I guess that's it? Bad TFI module?
Ill know for sure tomorrow. Gonna have my shop do the resistance check on the TFI just in case I wasn't using the ohmsmeter correctly. And if they find it faulty then Ill replace it.

Ill let you guys know what happens tomorrow.

Thanks again for the help

 

[Nelson674]

Well my mechanic confirmed that the TFI module was fried. He also got no reading over the first pin combo. Got the new one and took it home. Just out of curiosity I checked the new one against the old one to see what the readings would be. They both had the exact same readings over all the pin combinations. The first pin combo that showed no reading at all yesterday(and 10 minutes before at the shop) even showed a reading. I'm sure if I put the old one back in, it would fire up and die again, just like it had all along. Went to put the new module in and discovered that the only 7/32 sockets I have(required to bolt the module back on the distributor) are too short and too fat to screw the machine screws in all the way... I was using my brothers tools yesterday to take it off.

time to go to work, so I wont know if I fixed it till tomorrow

 

[RyanL]

I had to buy one of those TFI tools myself. It's a little star shaped finger wrench that has a hex shaft on it (maybe 7/16") so you can crank it a little bit extra if needed. I think that it was less than $10 at a local parts store. Yeah, I also had a TFI which was going bad and seemed to test okay doing those resistance readings (only one reading was off and it wasn't by too much). My guess is that the test only tells the tale if the TFI is totally bad (wont start) or is blazing hot (those things get super hot while running). When you went to test it, it was probably cooled enough to test fine.

 

[Nelson674]

I had to buy one of those TFI tools myself. It's a little star shaped finger wrench that has a hex shaft on it (maybe 7/16") so you can crank it a little bit extra if needed. I think that it was less than $10 at a local parts store.

I just used a standard palm ratchet with a deep 5.5mm socket. The 7/32 socket fits the machine screw but is too fat to fit in the hole. Whatever you used kinda sounds like the same setup.


Got the TFI all buttoned up. Turned the key and the truck fired right up. Before, the truck was dieing when the thermostat opened. So I let it run for a few min until I saw the temp gauge on the dash wake up. No problems and I let it run for another 5 min or so just to make sure.

Time for a test drive right? Wrong!

Soon as I shift into drive the engine sputters out and dies. Starts back up without and flinch. It seems like it would run all day in park or neutral. But when you put it in gear it either dies or the rpm just drops and it idles really low, like 500-600rpm.

Something I noticed but not sure if it would contribute to this problem.
On the gas pedal there are 2 cables. One is the throttle/accelerator? cable and I see people referring to the other as the "kickdown cable", It goes to the transmission. The Throttle cable has a plastic spacer and a spring on the end. The kickdown cable only has a spring. It also appears that when the gas pedal is fully depressed, the kickdown cable doesn't even engage. Seems like there should be a spacer there too? Admittedly I noticed this a long time ago, like when I bought the truck. But I never really thought too much about it because I never had any problems.





thanks again for the help guys, please keep sharing your thoughts.

 

[Nelson674]

Checked codes again.

After I checked them I read that you have to do it with the engine at operating temperature. So here are the results for cold and warm.

Don't know what 77 and 74 mean??

Gonna check that MAP thing out I guess..

KOEO (cold)

22 MAP (vacuum) or BARO signal out of range - MAP (Manifold Absolute Pressure Sensor)

(stored in memory)
22 MAP (vacuum) or BARO signal out of range - MAP (Manifold Absolute Pressure Sensor)

KOER (cold)

111 System checks OK

(stored in memory)
21 Engine Coolant Temperature (ECT) sensor out of range - ECT

77 System did not receive "goose" test - see TESTS

74 -Was brake depressed after engine ID was received ?
-Brake On Off (BOO) signal open or short to ground - BOO



KOEO (warm)

22 MAP (vacuum) or BARO signal out of range - MAP (Manifold Absolute Pressure Sensor)

(stored in memory)
22 MAP (vacuum) or BARO signal out of range - MAP (Manifold Absolute Pressure Sensor)

KOER (warm)

111 System checks OK

(stored in memory)
77 System did not receive "goose" test - see TESTS

74 -Was brake depressed after engine ID was received ?
-Brake On Off (BOO) signal open or short to ground - BOO