1998 Taurus SHO, wont start

[rain_beer]

I have a 1998 Ford Taurus SHO that I recently (one year ago) bought from my Father in law. He is a mechanic and the car was kept in great shape.
Recently, the car would turn over but would not start. No engine light. I checked all fuses and they were good. After waiting a few hours, the car proceeded to start right up. That was 2 months ago and since then it has run fine. This morning, the same thing. It wont start, it cranks fine just wont start. Again no check engine light. Has anyone else had a similar problem? Where do I begin to look? How can I check for spark on this Yamaha V-8, 3.4 liter when the plugs are under the coils? This car has a coil for every spark plug.

Help Please!

Thanks,

Max

[rain_beer]

PS. I forgot to mention the fule pump "energizes" when I turn the key. At least I can hear it.

[shorod]

Originally Posted by rain_beer

How can I check for spark on this Yamaha V-8, 3.4 liter when the plugs are under the coils? This car has a coil for every spark plug.

Boy, there's a controversial comment! Ford will disagree with you that this is a Yamaha-designed engine.

Anyway, with your Coil On Plug (COP) setup, just check one coil for spark. If that one coil has spark, then there is a good chance the rest of them have spark as well. You can remove the front appearance cover and 2 of the 4 front coils should be quite easily accessible. The middle two will require repositioning the IMRC servo, which is not a big deal. Use either a spark tester or a an old spark plug to check for spark.

Even though you hear the fuel pump running, you should check for fuel pressure at the rail. There is a Schraeder valve on the fuel rail that will make quick work of this, if you have a gauge with the Ford adapter.

Does the engine sound like it wants to spark (ie: sputters) or just crank evenly with no indication that it is sparking or trying to purge excess fuel? When you have the coil out, pull the spark plug and see if it is wet. If so, put the plug and coil back in, crank the engine for a few seconds, then hold the accelerator all the way to the floor and crank again. Does it attempt to start this way?

If you have good fuel pressure and you have spark, then inspect the secondary intake runner butterfly assembly. Maybe your IMRC servo is broken and keeping the secondary butterflies open. They should be closed below 3500(?) rpms. If they are stuck open, they may cause a hard start, especially when it's cold outside. It would usually also result in a rough idle.

-Rod

[rain_beer]

Originally Posted by shorod

Boy, there's a controversial comment! Ford will disagree with you that this is a Yamaha-designed engine.

Anyway, with your Coil On Plug (COP) setup, just check one coil for spark. If that one coil has spark, then there is a good chance the rest of them have spark as well. You can remove the front appearance cover and 2 of the 4 front coils should be quite easily accessible. The middle two will require repositioning the IMRC servo, which is not a big deal. Use either a spark tester or a an old spark plug to check for spark.

Even though you hear the fuel pump running, you should check for fuel pressure at the rail. There is a Schraeder valve on the fuel rail that will make quick work of this, if you have a gauge with the Ford adapter.

Does the engine sound like it wants to spark (ie: sputters) or just crank evenly with no indication that it is sparking or trying to purge excess fuel? When you have the coil out, pull the spark plug and see if it is wet. If so, put the plug and coil back in, crank the engine for a few seconds, then hold the accelerator all the way to the floor and crank again. Does it attempt to start this way?

If you have good fuel pressure and you have spark, then inspect the secondary intake runner butterfly assembly. Maybe your IMRC servo is broken and keeping the secondary butterflies open. They should be closed below 3500(?) rpms. If they are stuck open, they may cause a hard start, especially when it's cold outside. It would usually also result in a rough idle.

-Rod

Thanks Rod.

And yea hahaha I thought that remark (Yamaha) may get a reply :-)

Anyway, it turns over smoothly, but theres no indication or sputter that its even trying to start. It just cranks fast continuously, but no start. The #5 coil was replaced a year ago, but when that went the error code told me which coil was bad. I will check for spark at a front coil tonight and let you know. I just assumed if I had no spark I would get a code.

I dont have a fuel gauge with a Ford adapter, let me see if Dad in law has one.

Where is the secondary intake runner intake butterfly assembly? Is it the same as the IAC valve? I was told it could be this valve or the sensor.

I really appreciate your help with this.

Max

[e_powers]

not the cause of your problem. but great car from what i hear. when you get this problem licked if the cam shafts are not welded go and get them done pronto. camshafts are usually made from solid chunk of metal . and to save weight and money ford took a tube and pressed the lobes for the cam shafts on the 96-00'ish shos and the fix for this is to pop the valve cover and put a weld bead on each lobe. now if this is not done, one of the lobes will spin and cause the engine to eat its self . which most car owners do not want to happen. the problem in the sho world is called cam welding.

[Millermagic]

All 3.4 Yamahas (96,97,98,99 SHO) have the bad cams.

[brokenantimatter]

Originally Posted by e_powers

not the cause of your problem. but great car from what i hear. when you get this problem licked if the cam shafts are not welded go and get them done pronto. camshafts are usually made from solid chunk of metal . and to save weight and money ford took a tube and pressed the lobes for the cam shafts on the 96-00'ish shos and the fix for this is to pop the valve cover and put a weld bead on each lobe. now if this is not done, one of the lobes will spin and cause the engine to eat its self . which most car owners do not want to happen. the problem in the sho world is called cam welding.

Wow there is no proper way I can respond to this comment without getting a severe tounge lashings from Rod or Way2old.

First off 90% of production cams from '83 and up are press fitted not solid/ground.

Second off the lobes are not what walks on the cam, the primary and slave gear will separate, the reason is a design flaw which I have personally researched and concluded is most likely attributed to a camshaft design dispute between Yamaha and UAW/Ford.
Engineers from Local 1250 had to choose to make their camshafts from high grade steel or from a powered metal which would incorporate a different final shaft assembly that would include a bolted shaft and key lock on the cam gears.
They used the high grade steal assembly shaft design but produced the camshaft from the powdered metal, that is the design flaw.

[e_powers]

sorry not a sho owner just spouting what i read. needless to say welding the cam will extend the life of the engine. and after this problem is licked for the owner they should look into getting the welding done.

[shorod]

No tongue lashing here. I actually appreciate you saving me from having to type up that it is the cam gear that walks, not the lobes.

The IMRC butterflies are not the same as the Idle Air Control. The butterflies are located low in the secondary intake runners (the "tubes" that make the engine look so impressive). The IMRC box is mounted on top of the front valve cover, between the front center two coils and the the appearance cover. Follow the cable from the box to the butterfly cable cam.

-Rod

[rain_beer]

Originally Posted by e_powers

not the cause of your problem. but great car from what i hear. when you get this problem licked if the cam shafts are not welded go and get them done pronto. camshafts are usually made from solid chunk of metal . and to save weight and money ford took a tube and pressed the lobes for the cam shafts on the 96-00'ish shos and the fix for this is to pop the valve cover and put a weld bead on each lobe. now if this is not done, one of the lobes will spin and cause the engine to eat its self . which most car owners do not want to happen. the problem in the sho world is called cam welding.

I have heard of this problem with the SHO. And no, this cars cam shaft has not been welded. It has 140,000 miles on it. I guess ive been lucky so far, but after I get the thing to at least run, I will look into having the gear welded. Thanks for the info!

[rain_beer]

Originally Posted by shorod

No tongue lashing here. I actually appreciate you saving me from having to type up that it is the cam gear that walks, not the lobes.

The IMRC butterflies are not the same as the Idle Air Control. The butterflies are located low in the secondary intake runners (the "tubes" that make the engine look so impressive). The IMRC box is mounted on top of the front valve cover, between the front center two coils and the the appearance cover. Follow the cable from the box to the butterfly cable cam.

-Rod

OK Rod thanks, I will look at that this weekend. I havent done the spark test or checked the fule pressure because of the damn time change, by the time I get home from work its dark. I will work on this car Saturday and let you guys know what I find.

Max

[rain_beer]

Just so you know, I havent been able to start this car since Wednesday morning. As I stated before it turns over smooth, it doesnt sputter, it just will not start up.

[way2old]

Hey brokenantimatter. Post such as those deserve no tongue lashing. It is informative and what the forum looks for. Information. If you want to post from knowledge or experience, there will be more than likely nothing said to you. I appreciate the way you stated your thoights and information. As far as I can see, it is a very good post.

[brokenantimatter]

I would like to think positive here so you need to check, fuel pressure, spark, camshaft position, PCM.

But I remember when one of my sho's cams walked it would not start because the the intake vavles would not open.

Originally Posted by way2old

Hey brokenantimatter. Post such as those deserve no tongue lashing. It is informative and what the forum looks for. Information. If you want to post from knowledge or experience, there will be more than likely nothing said to you. I appreciate the way you stated your thoights and information. As far as I can see, it is a very good post.

Way2old I have been warned in the past for my profanity and flamming.

[rain_beer]

Hey guys sorry it took me awhile to reply, but it turns out it was the cam position sensor. Cost me $19.49 at a local Napa and took me 15 minutes to replace. So far (a week) the car has started up fine.

Thanks for all the help!

Max