Stan.Shaw@Excell.Net

I know you are trying to help, but please be careful. I didn't make such a statement nor intend to give that implication.

I am interested in where I should look and have some ideas. So many as to be a bit overwhelming. I did have this work done to avoid doing the work myself

Stan.Shaw@Excell.Net

While I presume this unlikely, wouldn't the car not run at all if this were true?

worf928

The most likely thing that would happen if you tried to do an engine full monty with the battery connected is that you would end up with a mild to deadly case of electrocution. But, I'd bet the car would be fine. In any case there's zero chance that the work done on your car was done with the battery connected. (Folks: Stan's not naming the mechanic that did the work but I know who it was (not me, btw) and thus I'm sure the battery was not connected during the motor work.)

Stan.Shaw@Excell.Net

Just trying to identify cause of my problems, so I can have a reliable 928 (if there is such a thing )

Stan.Shaw@Excell.Net

Knock sensors, 928.606.144.00, were replaced
Hall sensor, 944.606.170.01, was replaced (interesting 944 part number)
I don't think the CPS was. If you are willing to provide the full name and part number and I will re-check.

All vacuum lines were replaced using the kit offered here by someone who no longer posts here

I haven't checked this. Car was running fine under heavy acceleration even after the surge at idle and cold start problem (until toothed belt service warning came on... tensioner was rebuilt, etc.)

LH not rebuilt. I think I am going to send both computers out to be reviewed.
Injectors were cleaned, tested and replaced with new o-rings.
I think I am going to order the temp II sensor (why not...)

The idle control valve, 928.606.161.01, was replaced as well as the throttle switch, 928.606.157.00. So perhaps not the two you menion

Stan.Shaw@Excell.Net

Any thoughts on whether after market o2 sensors, at half the price as oem parts, they are attractive...

worf928

IIRC you have to cut the connector off of the old 02 sensor and splice it into the new one.

worf928

Why not? Well, throwing parts at a problem is statistically the most expensive way to fix a problem.

worf928

Stan, you have the ... ahh.... "unmentionable software" procured by the OC? Yes?

Why don't you hook it up to your car and see what it says? Among other things it will allow you to see what the temp-II sensor is telling your computers. If it does everything that the Hammer does - I assume it does - then you should be able to check the operation of the Impulse Sender (Speed Sensor - called CPS here), ISV, Idle/Wot switch (called TPS here), etc.

the flyin' scotsman

No you didn't but there is an issue with the car and in my mechanical experience returning to the last work typically leads to the problem; good luck.

Stan.Shaw@Excell.Net

Seems like a worthwhile effort to save 1/2 the cost of the part, and if that is the only difference, then it works for me.

Perhaps, but perhaps not when the value of labor is considered. If it takes me an hour to determine it is bad and then another hour to replace it, I would save an hour just by replacing it. After all time is the truly irreplaceable commodity

Ironically I don't, I will have to check with Mel Ward, as he has it from the last OC event. It is a thought I hadn't consider though!

Stan.Shaw@Excell.Net

I definitely agree that the likely cause of a new problem is where the last work was performed. Until problem determination is performed, then I won't know what the cause is and I am not presuming I have any idea what the cause is.

AO

Have you looked at any of the plugs? I think that's the first thing to look at. Then check to see if you have a good strong spark. How's your fuel pressure? Do you have a FP gauge?

I highly doubt it's the CPS. This is pretty much a go/no-go part and doesn't seem to be affected by temperature. One thing that does come to mind is the idle position switch. If you're not getting the idle contact, this can cause very hard starting when cold. The unmentionable software/tool will tell you if this is working or not.

Hope this helps.

Jim R.

Another vote for the idle switch. I had one become non-operational shortly after an intake R&R. Pretty easy to check for.

Also, pull the vacuum lines off the FPR and dampers, check for fuel. I split the diaphragm on my '89 last year. Again, easy to check.

Jim

Stan.Shaw@Excell.Net

The spark plugs are new, as are the plug wires, dist. caps and rotors.
The idle switch is also new.
I am presuming fuel pressure is good, as the car runs well normally.

The car actually starts well, but if I stall it (call me impatient) then it is hard to start.


Did you replace your idle switch during the intake R&R and have it fail afterwards, like it was defective?

I am presuming the FPR is ok, as under normal conditions the car runs fine.

Perhaps I should re-phrase the title of the thread as "start, if stalls, difficulty restarting".

I do appreciate all the thoughts here, thank you.