Cranks but no Start-- SOLVED

[Noobz347]

A little background-

I recently purchased this 95 SHO from a buddy of mine in Texas.

What an ordeal THAT WAS. Here's the story on that if you're the slightest bit interested - http://www.stangnet.com/mustang-forums/threads/misadventures-with-lasersvt.851967/

That story also tells the start of the trouble I describe in this thread.

I'm new to the SHO scene. This is the first I've owned but adds to the countless number of Fords I've had over the course of many years. I bought it as my DD. It needs some TLC and I've been slowly and will continue to fix/repair what ails it.

To the problem at hand:

When the car is cold, it starts, runs drives, no issues. When my buddy came to get me at the airport the thing died after sitting parked and idling for a while. We tried pulling codes but there were none. The intake was heat soaked and the DIS was pretty damned hot. We got it started at one point and made it about 100 yards before it quit again. Still no codes but we popped the hood and let it cool. The DIS is the car wasn't even 10 days old. We still got spark the entire time, verified by pulling a plug wire and cranking the engine over.

The next day after doing a bit of reading, I see that there's supposed to be dielectric grease between the DIS and the intake. No worries, we go get some, smear it on and the car operates fine for the remainder of the time that I'm in Texas and performs without incident for the 6 hour ride back home.

Fast forward to recent events:

I get up in the morning. Start the car, drive it to work. It sits for the day, I get back in it, start it up, drive it home, no worries. When I run into issues is when I drive it someplace, and it sits for only a short period. Then, it will often refuse to start. Each time, I still get spark, no codes, and have a thoroughly heat soaked engine bay. I sit in it with the hood up for a while and it eventually starts, stumbles, and runs like crap for a minute or so before acting right again.

My initial reaction would be to swap the DIS again but I wanted to check with you guys and see if there were OTHER sensors that I should also be looking at before I just toss another $110 at what might be a good part. I also have difficulty believing that this DIS is THAT fragile and unreliable.

I understand that there are crank and cam sensors that have the potential to cause these kinds of issues? Do their symptoms fit in with my description above?

Thanks in Advance,
Noobz

 

[SHOspazz92]

Try using HEAT SINK instead of electric grease for the DIS. Also, make sure that the water pump is not dripping over the crank sensor, causing it to freak out.

-Sam

 

[Noobz347]

Try using HEAT SINK instead of electric grease for the DIS. Also, make sure that the water pump is not dripping over the crank sensor, causing it to freak out.

-Sam

Do you mean thermal compound? I'd considering using Arctic Silver 5 in place of the dielectric grease but I see that the book calls for the grease.

As for the potential coolant leak, if there is one, I cant find it. I thoroughly inspected the cooling system shortly after I got the car back to my place. Even flushed and refilled.

 

[SHOspazz92]

Do you mean thermal compound? I'd considering using Arctic Silver 5 in place of the dielectric grease but I see that the book calls for the grease.

As for the potential coolant leak, if there is one, I cant find it. I thoroughly inspected the cooling system shortly after I got the car back to my place. Even flushed and refilled.

Understandable, Just know that the water pump sits directly on top of the crank positioning sensor and it only takes a little bit of seepage/leakage on to the CPS to turn it in to a worthless pile of non starting shit. =)

There of course has been 10,000,000 million arguments about heat sink and electric grease, who knows who is correct. I just know that when I overheated the living **** out of my engine (300* + water and oil temps), the car started each time (Had to shut down, restart for traffic...etc) with thermal compound/heat sink.

-Sam

 

[Noobz347]

Thanks Spazz... I'll give it a shot since I have the stuff sitting right here and it won't cost me anything to try.

I'll also double check any moisture getting to the crank position sensor.

 

[intimdatr]

i wondered when this car was going to pop up on the forum. I was sorta thinking Laser would with it but nonetheless good to know its on the Forum now.

Welcome in!

 

[Noobz347]

i wondered when this car was going to pop up on the forum. I was sorta thinking Laser would with it but nonetheless good to know its on the Forum now.

Welcome in!

Thanks.

If you know LaserSVT at all then you'll definitely want to read the story that I have linked above. It's classic LaserSVT. :frantic:

 

[intimdatr]

Lol i did read it! It was rather amusing! My brother is pretty big on LVC and he got a rather big kick out of the story! But from what i hear The SHO you got is a pretty good screamer (beat a healthy mark) and has a the ingals adjustable control arms installed by Laser for you. Over all its a great looking car. Cant give laser TOO much crap hes a Mark guy . LOL.

 

[Noobz347]

Lol i did read it! It was rather amusing! My brother is pretty big on LVC and he got a rather big kick out of the story! But from what i hear The SHO you got is a pretty good screamer (beat a healthy mark) and has a the ingals adjustable control arms installed by Laser for you. Over all its a great looking car. Cant give laser TOO much crap hes a Mark guy . LOL.

Laser is definitely one of the good guys. :angelnot:

I'm at the portion of the SHO story where I'm addressing the neglect etc. from previous owners. I'm slowly replacing under hood hoses etc. and I really need to get in there with some POR-15 and bring the cancer spots to a screeching halt.

All in all, it runs pretty well. I just want to ensure it has the kind of reliability that it had when it was new then see what happens from there.

Laser had suggested the control arms vs. replacing just the bushings (which were totally smoked). They are DEFINITELY a nice upgrade vs. the OEM pieces. For the price of the things... there's no way I could pass it up. There are some brackets here and there that I want to replace but once I'm sure it's all solid, I think I'll be going for a set of sub-frame connectors.

More on that sort of thing as I read and figure out what the important things are on these cars.

As a footnote: I've got an intercooled Vortech V-1 S-trim lying around. I've seen a thread here and there about supercharged setups. All I know at this point is that I don't know enough to know whether it will be feasible or not.

 

[itwonder]

It is really difficult to detect a small leak from the WP onto the CPS. But your problem is typical of a failing CPS. You should just go ahead and do a front 60K service, which includes a new WP and CPS. Use any kind of heat sink compound between the DIS and the intake; Radio Shack PN 276-1372 is fine.

Nice looking SHO!

 

[rubydist]

My red 94 did this from time to time - what would happen is that it would flood out with a relatively short heat soak, apparently some of the injectors would not always shut off, so it would do two things: 1) leak fuel into manifold so it would flood when trying to start, and 2) leak down the fuel pressure so it took a few seconds to get fuel going again after it did fire.

So, the solution was: if I needed to re-start after a short heat soak, and if it did not start normally, then push the gas pedal to the floor when cranking - this shuts off fuel during cranking to clear out the flooding. You may also need to cycle the key switch on for a few seconds, then off, then on a few seconds - repeat a few times to allow the pump to build up fuel pressure again.

Try that the next time you have the issue. If that helps, then some injector cleaner in the gas or an injector flush would be in order.

 

[AREA 91]

I would check the fuel pressure.

 

[Noobz347]

My red 94 did this from time to time - what would happen is that it would flood out with a relatively short heat soak, apparently some of the injectors would not always shut off, so it would do two things: 1) leak fuel into manifold so it would flood when trying to start, and 2) leak down the fuel pressure so it took a few seconds to get fuel going again after it did fire.

So, the solution was: if I needed to re-start after a short heat soak, and if it did not start normally, then push the gas pedal to the floor when cranking - this shuts off fuel during cranking to clear out the flooding. You may also need to cycle the key switch on for a few seconds, then off, then on a few seconds - repeat a few times to allow the pump to build up fuel pressure again.

Try that the next time you have the issue. If that helps, then some injector cleaner in the gas or an injector flush would be in order.

Edit:

Oh... and on the water pump suggestion:

How much of a PITA is the pump to change on these cars?
There has been a time or two where I smelled fuel but it was after cranking on it for a while. I just figured that the injectors were pulsing but it wasn't firing up and that was casing it to load up on fuel.

I do plan on getting a gauge pillar and fuel pressure gauge here in the near future (along with oil press, water temp).

In the meantime, I've removed the DIS, sanded both surfaces, polished them to a mirror finish, and applied a liberal amount of Arctic Silver 5. I'll report back whether there's a change.

Where's a good place to get a pillar pod for the 95? (in case I do find any problems there)

 

[jayro]

1) leak fuel into manifold so it would flood when trying to start, and 2) leak down the fuel pressure so it took a few seconds to get fuel going again after it did fire.

So, the solution was: if I needed to re-start after a short heat soak, and if it did not start normally, then push the gas pedal to the floor when cranking - this shuts off fuel during cranking to clear out the flooding. You may also need to cycle the key switch on for a few seconds, then off, then on a few seconds - repeat a few times to allow the pump to build up fuel pressure again.

Try that the next time you have the issue. If that helps, then some injector cleaner in the gas or an injector flush would be in order.

This is what my first thought was. Especially since you said when it does start up, it will stumble some and then clear up.

It sounds like you verified spark during the no start episode, so I would think the CPS would be good. If the CPS is bad then you usually don't get spark.

The water pump isn't terrible to change. It depends on what your definition of PITA is. It requires removal of a number of things on the front of the engine (passanger side), but it is fairly accessable through the wheel well.

And on the heat sink/dielectric debate, I have always heard and used heatsink.

 

[Noobz347]

Well... no luck so far. Took it to Home Depot and it did just fine. Started right back up when I came out.

I ran the **** out of it on the way home then let it sit for 15 minutes or so. Here's a video of the result:

http://youtu.be/xefi18N2fDc

This of course if AFTER having removed the DIS, cleaned it, applied Arctic Silver 5 and reinstalling.

Maybe the video will look something like the symptoms you guys had.

 

[Noobz347]

Went back out after uploading that video and making that last post (maybe another 20 min or so) and it cranks right up (again, stumbling at the very first then right as rain).

 

[intimdatr]

as heat increases resistance maybe were looking at a bad ground somewhere? have you checked and cleaned all of them(or laser)?

 

[Noobz347]

as heat increases resistance maybe were looking at a bad ground somewhere? have you checked and cleaned all of them(or laser)?

Normally, I would like that idea but it ONLY does it after the car has been run for a while and sits for a few minutes. If it were a bad ground, you'd think that it would have a symptom while the car was warm and running too.

 

[intimdatr]

Agreed.
But with the ground of the DIS being through the intake and with heat soak it could be causing ground issues in the ground strap on the back of the intake causing it to have to guess? Which would be most present when starting because it has to guess the most?

Last time the plugs and plug wires were changed?

Sorta a random thought, does it seam like a flooding issue? another member posted about flooding problems.

 

[Noobz347]

I think Laser swapped the plugs before he sold it to me. I'll check with him to be sure. The wires look fairly new (for whatever that's worth).

I saw the post about the flooding issues and it's definitely on my list of possibilities. With what's going on, it seems like the most feasible given his description and the symptoms. I say that because it only seems to do it after a 20 (or so) minute heat soak. The part that I think is against that theory though, is that you'd think it would have a hard time starting when it was cold too (the fuel would still be sitting in there).

I'm open to all suggestions though. You guys know more about this car than I do.

In the meantime, I'll take a look at the grounding strap. I did take a dremel brush to the mounting hardware of the DIS when I had it apart, to remove all the rust etc. from the screws. I'll do the same to the grounding strap and see if there's any difference.

Thanks all.