Mrmerlin

and a fuel pressure regulator they all look the same the FPR is on the passenger side rear fuel rail the dampers are on the front center of the engine and the DS rear fuel rail.

NEW info......... you used teflon tape to seal the temp 2 sensor ????
fix this first.
please fit a copper sealing washer,
if you remove the sensor from the bridge you wont lose much coolant,
if this fixes the problem then your golden.
if not then pull off the aircleaner and inspect the vacuum lines as previously suggested

90 S-4

Mrmerlin -- I'm following your instructions this Saturday, can't get near it till then -- Thank you !

dr bob

If you don't yet own a MitiVac or equivalent, now would be a time to invest in one. Use it on each of the dampers and the fue pressure regulator to make sure they don't have ruptured diaphragms. When they leak fuel into the vacuum system and ultimately the manifold, the car will be flooded/hard to start, then clear up as the ingeted gas is burned off.

The next possibility is a leaking injector, but we'll burn that bridge when we come to it.

Leon Speed

The save power message indicates a voltage problem. Might just be from a lot of cranking when trying to start. Charge the battery to full and see if it clears up.

John Speake

If it runs fine after a flakey hot start, I would suspect leaky injector(s).

A fuel pressure gauge on the end of the fuel rail would help confirm this. (leak down test of fuel pressure after shut off)

Bertrand Daoust

First, regarding your "Save Power" message:
What Andrew said: Low RPM = not enought power from the alt and the computer thinks that the alt is not working like it should. Directly related to your warm starting problem.

Second, warm starting problem:
Exactly what Mrmerlin and Dr bob said: I had the EXACT same problem with mine about 3 or 4 years ago and it was the FPR and the rear FPD that were leaking.
Not mutch, but enough to cause me some starting problem like yours. While there, I changed both FPD and the FPR and it fixed the problem right away.

Not 100% sure, but if I remember well, I did have the "Save Power" message at the same time, few times.

+1 on the MitiVac. Very useful.
Ho yes, +1 that both the FPR and the FPD look the same. Check the part# first and make sure that you put the right one at the right place. Ask me how I know...

Good luck.

AO

I would not say that is a definitive test. A worn/leaky check-valve can also cause fuel pressure to wane but without the deleterious symptoms.

Mrmerlin

if the car is hard to start hot and seems flooded its usually a bad FPR or FD or leaking injectors.

AO

And my experience has told me it's usually an isue with the Temp II sensor or the signal from the Temp II. Not to discount your experience, just interesting to note.

Mrmerlin

either one of these suggestions are easy to investigate and fix

90 S-4

I really appreciate the helpful ideas, I think I'll try them in this order ..

1. remove teflon tape > Mrmerlin
2. gauge on the end of the fuel rail, confirm pressure, stable > John S.
3. Mitivac the dampeners > dr bob
4. re:check valve, after sitting one week it starts instantly with out the
pump coming on so I think the ck valve is good ? yes ?
5. full charge on the battery > Aryan

6. If not any of the above than ck the signal from the temp 2 > Andrew
but not sure how to do it ..

I have an old Devek adj FPR on there now, should that be checked as well ?
Is the rear FPD the only suspect, what about the one on the front ?

Thanks

Mrmerlin

Ahh on 3 you will want to add smell the vacuum lines for gas before plugging in the mitivac
and there are 2 dampers and one FPR the front damper and the driver side rear damper remove the aircleaner bottom to find these parts

90 S-4

Update, the fuel pressure regulator appears to be bad, I borrowed a friends
MitiVac (thanks dr bob, I'm buying one now) the two dampeners held
16 inches for 60 sec + Then I checked the FPR, pumped it up to 16" and
the needle fell as fast it could escape through the 1/8" hole in the mitivac ..
The Regulator is an old Devek part, its adjustable. Its probably 20 years old
so no wonder it finally gave up, its been a pretty good regulator so I don't
know if I should try to rebuild it or just get whatever the latest thing is you guys are using. I need one to be adjustable, what kind and where to get ??

The teflon tape on the temp 2 sensor really wasn't a problem because the
crush ring was clean of tape and was making a pretty good ground.

The battery was fully charged, etc ..

blitz928

+1, this fixed my warm start issues.

90 S-4

Thanks Mrmerlin, you called it right off the bat ..