99 explorer xlt died going down the road now wont start back!

[john97mount]

Well like the title says my 99 xlt died going down the road and wont start back. Admittedly i have been driving it with a pretty bad tick or rattle for about 50 miles but it was so faint before this 50 miles i mistook it for a slight exhaust leak.

This rattle seemed to be getting worse right before it died so at this point im attributing it to timing chain issues. But i have some questions for the vets of this problem. would this engine with bad timing chains still have compression on both banks?

compression on both banks is 152 +/-
fuel pressure around 55 with 5 psi leak down
have spark at coil and at end of wires
driver side plugs look normal
passenger side seems to have raw gas on them
starting fluid will not start it up
about the only thing we didnt check is a noid light on the injectors
ah yes, and right after it died i removed the filter and saw a slight vapor or mist in the intake (guess that was exhaust if timing chain died)
engine turns over free not locked up

Wanted to run this by someone with experience with the situation before we go pulling this motor. But from everything i have read it sure sounds as though the passenger rear (of course)timing chain let loose. Had i only realized before how easy replacing the tensioners seems and researched this noise, but i just didnt have time!

 

[2000StreetRod]

compression

A compression of 152 psi is about 30 psi low but does not indicate any major change in camshaft timing. Was the throttle plate wide open when performing the test? How many miles are on the odometer? However, 150 psi is plenty for the engine to start and run. I suspect there is some other problem.

Did you try depressing the accelerator all the way and then cranking the starter?

Your 1999 Explorer has a returnless fuel system. Your fuel pressure should be 65 psi +/- 8 psi. 55 psi is a little low. You might try cleaning the crankshaft position (CKP) sensor connector contacts by disconnecting/reconnecting the connector a couple times.

 

[john97mount]

A compression of 152 psi is about 30 psi low but does not indicate any major change in camshaft timing. Was the throttle plate wide open when performing the test? How many miles are on the odometer? However, 150 psi is plenty for the engine to start and run. I suspect there is some other problem.

Did you try depressing the accelerator all the way and then cranking the starter?

Your 1999 Explorer has a returnless fuel system. Your fuel pressure should be 65 psi +/- 8 psi. 55 psi is a little low. You might try cleaning the crankshaft position (CKP) sensor connector contacts by disconnecting/reconnecting the connector a couple times.

Throttle plate most likely was not wide open during test i dont remember specifically trying that, however it was held to the floor at several points trying to get it started. 212k on the odometer , i dont know how its been treated its whole life i just bought it as a toy a few months ago and put maybe 500 miles on it so far.

We were aware the fuel pressure should be 65 but thought that at worst a couple points below that +/- 8 may result in running rough but not unable to start. (always possible thanks)

We will try the CKP , i think my friend and i were under the impression the CKP fired the coil so it must be ok. we will check that out thanks!

Another tidbit i forgot to mention is the tachometer is dead when trying to start the truck, i think i remember reading something somewhere about this pointing to something, ill search the forums.

 

[2000StreetRod]

PCM drives the tach

The PCM drives the tachometer based on the CKP sensor output. On my 2000 Sport the PCM enables the fuel pump for a couple seconds when the ignition key is switched on and any time the crankshaft is rotating as reported by the CKP sensor.

 

[john97mount]

what role does the cam shaft position sensor play in all this ? is it like a conventional engine or do the ckp and cmp read off one another and let the computer decide or what? as you can tell, we probably have a small problem here however im lost haha.

 

[john97mount]

ok new development, was trying to start it with a friend under the hood and we have white/grey smoke coming back through the intake. a slight backfire and ofcourse, still a no start condition.

After seeing this with my own two eyes, im starting to think its possible for a timing chain to be out and still have compression. I cant find anything about it here though.

 

[Turdle]

Just for giggles, and it won't cost cent.

Disconnect the crankshaft sensor ( about 11 oclock on the crank pulley) and reconnect it. Tap the sensor with the handle of a screwdriver.

Then try starting the truck again, holding the throttle to the floor while cranking it over. while doing this have someone watch the crank pulley to see if it is turning.

 

[2000StreetRod]

how many cylinders for compression?

Did you check the compression on all cylinders or just one on each bank? If you haven't tested all cylinders I suggest that test them all. You could have a broken valve spring in one cylinder or a "thrown" cam follower.

The camshaft position sensor "tells" the PCM if cylinder 1 is on the compression stroke or the exhaust stroke. All precise timing of injectors and ignition is based on the crankshaft position sensor output.

 

[john97mount]

Just for giggles, and it won't cost cent.

Disconnect the crankshaft sensor ( about 11 oclock on the crank pulley) and reconnect it. Tap the sensor with the handle of a screwdriver.

Then try starting the truck again, holding the throttle to the floor while cranking it over. while doing this have someone watch the crank pulley to see if it is turning.

did this, and its turning. hard to get a screwdriver in there but tapped on it i wouldnt say banged though. no start.

 

[john97mount]

Did you check the compression on all cylinders or just one on each bank? If you haven't tested all cylinders I suggest that test them all. You could have a broken valve spring in one cylinder or a "thrown" cam follower.

The camshaft position sensor "tells" the PCM if cylinder 1 is on the compression stroke or the exhaust stroke. All precise timing of injectors and ignition is based on the crankshaft position sensor output.

one on each bank, ill go get the compression tester!

if the cpm tells the pcm about stroke then wouldnt it seem possible for it to be the culprit?

 

[2000StreetRod]

Camshaft position sensor

. . . if the cpm tells the pcm about stroke then wouldnt it seem possible for it to be the culprit?

The OHV V8 and probably the OHV V6 will start and run (but poorly) with a bad synchronizer. I've read the SOHC V6 will not start with a bad camshaft position sensor. However, I have been able to start my engine (and run for about 2 seconds) on aerosol starting fluid with all of the injectors disabled. Since your engine would not start on starting fluid I don't suspect you have a bad CMP sensor.

 

[john97mount]

The OHV V8 and probably the OHV V6 will start and run (but poorly) with a bad synchronizer. I've read the SOHC V6 will not start with a bad camshaft position sensor. However, I have been able to start my engine (and run for about 2 seconds) on aerosol starting fluid with all of the injectors disabled. Since your engine would not start on starting fluid I don't suspect you have a bad CMP sensor.

thank you for the clarification! i had already cleaned it and reinstalled with negative results at this point haha.

 

[john97mount]

Did you check the compression on all cylinders or just one on each bank? If you haven't tested all cylinders I suggest that test them all. You could have a broken valve spring in one cylinder or a "thrown" cam follower.

The camshaft position sensor "tells" the PCM if cylinder 1 is on the compression stroke or the exhaust stroke. All precise timing of injectors and ignition is based on the crankshaft position sensor output.

ok we compression tested cylinders 1-135 psi, cyl 4-165psi, cyl5-180 psi, cyl 6-130 psi.

We didnt bother testing the two hard to get to cylinders because although the compression is not beautiful it is however existant and doesnt seem like the timing chains are the problem.

Spark plugs were all soaked in fuel. If we dropped valves in cylinders 2 or 3 it should still start on just 4 cylinders right?

At this point, the only explanation we could come up with is the cpk sensor is "kind of bad" . And im left wondering if this is even possible.

 

[john97mount]

new crank position sensor, still no start, still no tachometer movement. very frustrating.

 

[2000StreetRod]

starting requirements

The three requirements for an engine to run: fuel with air at the correct ratio, compression and properly timed ignition.

You've tried starting fluid with no luck. Your spark plugs are wet with fuel from cranking the starter but not firing. That indicates the injectors are pulsing. The fact that the engine died while the vehicle was driving is significant. Maybe the air/fuel ratio is too rich. Try disconnecting the vacuum hose from the fuel pressure damper on the fuel rail and see if fuel is present.

Sometimes the diaphragm in the damper will rupture allowing fuel to get sucked into the intake manifold.

The engine dying while driving is typical for timing chain slippage, broken valve spring or thrown cam follower. With compression as low as it is on cylinders 1 and 6 and only cylinder 5 with good compression I doubt the engine would start on just 4 cylinders. I suggest that you check the compression on the other two cylinders (2 & 3).

What was the condition of the four plugs you removed? Were they gapped properly? Were there signs of detonation or fouling? What brand of plugs are they? Did you confirm spark at all six plug wires? Your Explorer has a waste spark system. Plugs are paired. When one plug fires on the compression stroke its "mate" fires on the exhaust stroke.

 

[john97mount]

The three requirements for an engine to run: fuel with air at the correct ratio, compression and properly timed ignition.

You've tried starting fluid with no luck. Your spark plugs are wet with fuel from cranking the starter but not firing. That indicates the injectors are pulsing. The fact that the engine died while the vehicle was driving is significant. Maybe the air/fuel ratio is too rich. Try disconnecting the vacuum hose from the fuel pressure damper on the fuel rail and see if fuel is present.
View attachment 84270
Sometimes the diaphragm in the damper will rupture allowing fuel to get sucked into the intake manifold.

The engine dying while driving is typical for timing chain slippage, broken valve spring or thrown cam follower. With compression as low as it is on cylinders 1 and 6 and only cylinder 5 with good compression I doubt the engine would start on just 4 cylinders. I suggest that you check the compression on the other two cylinders (2 & 3).

What was the condition of the four plugs you removed? Were they gapped properly? Were there signs of detonation or fouling? What brand of plugs are they? Did you confirm spark at all six plug wires? Your Explorer has a waste spark system. Plugs are paired. When one plug fires on the compression stroke its "mate" fires on the exhaust stroke.

No fuel out of the damper hose. No bueno. This truck is an anomaly. I will either send it hurling from a tall cliff or leave it alone for a while, of the two I think just leave it alone.....however, I feel the timing is just thrown off by the cps or CPU. But like I said, break time! (Months) be back when I DO have an answer.