Okay guys for full disclaimer I sent a PM to Brutal with the same and hopefully he'll answer but instead of waiting I'll ask all of you for some directions on this.
I have a 2004 STR that's behaving very odd in the sense that if I turn the key when is warm the car not only it doesn't start but it behaves like the starter would be bad or the battery not having enough crank amps meaning it the lights go off and it just clicks one time. Other times it cranks but it doesn't start or if it starts it starts after about 5-10 sec of cranking the engine. When is cold however it still takes longer to start but that would be about 3 sec. I just rebuilt the starter so it is unlikely it would be that. I pressed the fuel pressure valve (I think it is on the return hose) while cranking the engine and no gas came out. I can feel the gas flowing to the engine but it might not be the right pressure. I did check all the relays and fuses and are fine, the fuel intertia/reset switch is pressed ...
Would you have any advice on how to diagnose the issue. I do have the right tester (Autel) and I can read live data but I don't know what should I be looking for and what values. Thank you in advance! Bob

 

You should be able to read fuel pressure. There's no return line.

I'd also check each sensor you can understand (you'll manage at least the temperature ones) for plausibility both when cold and hot, hoping to see one that's bogus.

Bear in mind Brutal probably gets a lot of PMs and has a living to earn too, not to mention his toys can keep him busy.

 

Thank you for the response JagV8, I'll record the values cold/hot and will post them here. This is probably the car with the weirdest problems I have ever seen/had...a year ago you might not remember you pointed me towards the electrical harness and you were right I had a clogged cat that overheated and melted the harness above it so I replaced it with another, haven't had problems since ...until now
I know Brutal and everyone here has to earn a living and have other things to do than just be on the forum I have no doubt about that

 

I'd completely forgotten!

After so long it's probably unrelated but anything you could double check without terrible difficulty would be worth doing.

 

JagV8, I plugged in the obd2 and read all the data, nothing seems to be off. I got 55psi at idle cold and hot, fuel trims look fine, MAF is at 0.01lb/s (15kg/s) O2's are normal, alternator pushes 14.5v, car started normal cold drove it to work (5 miles) it got to normal temp stop/start took a lot longer but it started. It shows the same symptoms as it would have no fuel or no spark, almost like the timing would be off by a little, since it does it only when cold that would take the timing out of ecuation (I think). Any hint on what to do next?I have no stored or pending codes, all monitors are ready btw. I recorded all the live data and would be able to pull it when I get home if needed.

 

Temp sensors (ECT, IAT) plausible? And ECT heats faster and a lot further than IAT?

Did it go CL (closed loop) in (say) 30 secs?

Just hoping for an anomaly that might show up in OBD.

(Looks good so far.)

BTW, that's a lot of metric air

 

all temp sensors are plausible. ECT heats up almost at the same rate as IAT a bit slower if I am not mistaking. It went CL almost instant. I kept thinking and got with a guess (uneducated one) could this be two things ... 1. a loose wire giving the intermittentclick no power at warm start and 2. the crank sensor that acts up when engine is hot/warm?

 

ECT should heat much faster and get far hotter. It's the coolant

Some things it might be that don't throw codes:
chafed wire that moves / thing it rests on gets hot / etc
dribbly fuel injector?

I don't think it could be CKP... well, yes maybe, just kinda sounds unlikely

Someone must have better ideas.

 

I'll check ECT behavior keeping in mind what you said. If that's not the case (ECT is slower than IAT) could that be the culprit? BTW I'll check for lose or damaged wires although I have to say that every wire on this car sits on some potential frying pan or grill ... Ford engineers that put the S-type together must be some of the worst ever looking at how they cobbled together all the wires (I can hardly call the thing a harness).
Re dribbly injector, it could be but wouldn't that always be dribbly when hot or it is a "when it happens" thing?

 

ECT kinda must do as I posted.

It uses all such OBD sensors to control fuel so if one's wrong so is air/fuel ratio.

I'm not an injector expert, just know they can dribble and cause hot start problems.

 

Just checked the ECT/IAT and you're correct ECT started from 78 F and went to 183F while IAT started at 68 and got to 78F then decreased to 73F on the hwy. WIll check for wires and connections a bit later. THANK YOU FOR ALL THE HELP!!

 

Trouble is, not found any helpful stuff yet!

 

JagV8
I checked all cables and connections that I could reach on top of the engine and underneath and got nowhere. Here is the live data ported in excel for easier sorting had to zip it as xls is not allowed. If you want and have some time please have a look maybe you can see something I missed. Thank you in advance!

 

seems to be boosting hard at around idle map is between 5 and 9 psi below 700 rpm ?
and below 20% tp and under very low load , is this normal? i will have to check mine , but it doesn't sound right .

 

Bearing in mind TP is auto-calibrated (mine reads higher) I'm not sure quite what you mean is or isn't normal. Lack of punctuation etc isn't helping!

I didn't notice anything worrying but data from another STR wouldn't hurt.

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So far I think OBD just isn't seeing the reported problem, and if that's right it rules out a ton of stuff.

 

Tried to replicate some of the values shown ,but can not match them all ! It does seem that the map is correct thou , at 5psi around 1000rpm don't know how you managed to get 7psi boost at 650 rpm mine won't even rev that low! Mine has the 3% top pulley and is 1psi lower at 100rpm higher no throttle ! Also not sure about both your tp reading higher than mine .
My tp is 3% at idle and 13%load and 4psi at 750rpm at idle in gear warm ,
85•c ect and 13•c iat ,

Mine At 20% load is 10% tp ,7psi and 1100rpm same temps!

 

update: the culprit was the starter; although I refurb it seems it had other problems than the contacts. On an impulse I bought a ACDelco refurbed starter and replaced the old one, the car has no more issues starting at any temperature. it actually starts faster than ever before. No idea what the relationship between the starter and lack of starting when hot even when the starter seemed to turn normal...

 

Thanks for letting us know. Someone else may hit the same thing.

 

Good to know and we have not seen any starter problems on the STR.

But the age of the car is such we are seeing new problems as the years and miles roll up.
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