Courtshark

The 87 I picked up and resurrected is almost done and will be for sale soon. One rennlister has called dibs, but if he passes, I'll be posting it here.

Before a sale can take place, though, I need to stop chasing a ghost I've done a million searches on this site and can't seem to find a thread that replicates the following:

The car fires right up on the first try when cold, and idles high (cold idle) and slowly settles down to around 1000 rpm. It runs very smoothly and nicely for several minutes. I usually blip the throttle a few times, no problem, and it settles right back to 900-1000 rpm.

Then, after a few minutes, like someone hitting a light switch, it cuts off. Now it starts and instantly stalls, unless you help it by giving it gas. Checked and replaced fuel pump relay with known good one. Cleaned all grounds except the ones "in the valley" under the fuel pressure regulator and dampner (because I could not find them! Is there a better diagram than the one I found on this site, or photos of them all?). I am guessing a temp sensor is bad, or another relay or ECU is having a solder melting syndrome when it gets hot enough. Another possibility is the MAF, though that seems to be working fine.

Also, can ECUs from autos be swapped into 5 spd 928s? (i.e. can my 88 be a temporary donor?)

TIA!

perrys4

My stalling problem was when cold but it seemed to be the ISV. Sprayed it with wd40 and all seems okay now. Worth a try.

Jerome Craig

Spraying WD40 into ISV vauum line did the trick for me two weeks ago.... similar problem.... start...then stall.

Shark Attack

does it crank normal on the restart?

Vlocity

Is it an automatic ? Have you checked the thrust bearing play?

Ken

Courtshark

It cranks and starts, but won't stay running without blipping the throttle.

It is a 5 spd.

Vlocity

Thats a relief. (5 speed)

Ken

WICruiser

Can you here the throttle position switch click at idle? Without a signal that the throttle body is at idle I believe the ISV is not activated and it will die. When it is cold I think there is a different circuit in play that provides enough fuel/air to idle.

tomcat

Hey, what do you know? And what's that in your avatar? You partying without us?

Jerome Craig

While you guys were hanging out in Boston, I did my motor mounts, pan gasket, oil pressure sending unit, cleaned all the grounds, repaired broken ground wires, sent my MAF off to be rebuilt, oil change, etc., etc., etc.. I would have replaced the alternator but it arrived just after I had put the bottom pans back on.

Guess which one is the old one


Riding high now...


.... And a little "eye candy" for Frenzy11


I'm coming up on 100,000 miles AGAIN... it's the third time for me... so I'm going through a lot of the systems checking and replacing stuff.

See ya...

Jerome

Courtshark

Not sure what to listen for. Can you describe the click for me? Thanks!

New development this AM: it cranks but won't start. Joy.

WICruiser

With the engine off and the hood open actuate the trottle by hand (or have someone press the pedal slowly). Slightly off idle you should hear a distict mechanical click sound as the throttle is opened and again as it closes. This is the throttle position idle switch (there is also a wide open throttle switch). If you do not hear the click you can check the electrical signal from the switch (not sure where specifically on the '87 - on my '85 there is a diagnostic port on the top fron of the engine).

The throttle position switch (contains both idle and WOT) is mounted to the throttle body and adjustable for position. So if you don't have the click check for adjustment before you replace.