Tamaren

Hello,
I have gone through a lot of the things on my 928 and getting my 928 to the best shape possible, however, I'm trying to figure out these last few issues I'm having. Car is an '81 US 5 speed.

1) Idle fluctuation and hiccup on acceleration at operating temp. I have replaced the fuel filter, all new injectors, and have constant 29psi at idle when cold.

My next step was fuel relay (which gets hot when running) and temp 2 sender.

2) Hot start problem. Standard, if you shut it off and then try and start it, it cranks forever. Cranks a few times when 'cold' (50 F).

I think its the check valve, but I ordered the one from pelican and it wasn't the right one.

3) Runs hot in traffic, cool on the highway. This is less of a concern, I live in Phoenix and I overheat in 100 F as well, and the car approaches the 240 F? line, white line, not red) and fans kick on and drop it back down. Is constant temp possible?

4) In car gauge shows 13v right after stars, then slowly dropped to 12v. New alternator, new battery, all grounds are good. Guage also moves with turn signals, lights, exc. Haven't taken a multimeter to the battery to get a direct result for charging.

All help is appreciated. Thanks!

Wisconsin Joe

3) - Temp gauge is notoriously unreliable as far as actual temp goes. It is reasonably consistent and repeatable - to put it another way, figure out where it usually runs and if it goes up from there, then there's something to check. You can put an IR temp gun onto the engine to determine what actual temps the gauge is telling you. Also, it's a "real" temp gauge. It goes up and down as the coolant temp does. Some (many?) modern cars that have a temp gauge actually have a "warning light" masquerading as a gauge. They show "normal temp" for a wide range of normal temps, but go up if the car overheats.

4)Voltmeter is often off. Like the temp gauge, determine actual values and see what the gauge says. I think you can find tune the VM to show what it should with an adjustment screw on the back. And, again like the temp, it will fluctuate with the load, as the volts are in the system. Mine bounces up and down with the turn signals too.

Both of those sound normal to me.

Tamaren

Okay, Thank you. I figured they were okay, and with the IR thermometer there was nowhere I was particularly worried about, head temp was cool. Whenever it warms up again I will check.

I'll put a multimeter on it next time I get a chance and make sure she is charging at 13.6 or so. Thanks!

Knock the last 2 off the list.

Barry Chan

#2 hot start could be your fuel dampener, pull hose if theres fuel, it needs to be replaced.

battery at rest should read 12.6, running 13.8 or higher

Tamaren

I didn't think '81 had a fuel dampener? It's not where it is on the CIS cars at least. Where is it?

Rich9928p

Hello Tamaren,

I see you live in Phoenix. There are several 928 Porsche owners in the Phoenix area. Drop me a line at info@electronikrepair_dot_com and I'll introduce you to the group.

We may be able to assist you.

Rich
928 Owners Club Charter Member & Membership Chairman
1993 928 GTS Cover Girl
1987 928 S4
1979 928 5-speed - also a Cover Girl
1979 928 track beast