S4ordie

Wow, 60 posts and not one seasoned Rennlister has advised/ordered you to.....

REPLACE ALL FUEL LINES NOW

Low mile cars that have sat for very long periods of time, especially in a dry climate, rot out their fuel lines. These wonderful cars, or rather new or neglectful owners, have a horrible history of catching fire.

There are 1,345,683,412,789,433,672 warning threads about these cars relative to fire losses. Here is a current one https://rennlist.com/forums/928-foru...uel-lines.html

You have a beautiful car, the issues you are having with it are correctable. Letting the car destroy itself due to old fuel lines should be a criminal offense.

Roger at 928sRus has a complete kit. Greg Brown also sells fuel line replacement kits made out of materials suitable for NASA.

AirtekHVAC

Well said....how'd we miss that????

ryalex

Fuel lines are a good idea.

Well, Carl's Place was able to quickly find the bad wire causing the fuse #24/door chime/no lights issue, it was under the trunk release button. The only other thing they could find was a bad ring on a seal which was losing some pressure they replaced. Said the fuel system appeared to be working with seal and CO2 reading ok. Their thought on the lost power was that the muffler/exhaust system was clogged.

So I went back today to the muffler shop and had them put a smaller, higher flow exhaust on. The stock muffler was crusty, heavy and did have some crumbled cat-stuff coming out. However, with the de-cat/straight pipes I think I have made it a little too loud now.

But that hasn't resolved the lack of power issue. I'm going to send a MAF and fuel brain to Rich for diagnosis.

Hilton

Sending the MAF out for testing is an excellent idea.

Landseer

So is going back into the timing belt and replacing the waterpump with the correct one and correct pivot bolt.

Hai gebissen

Wait, prior to having the cats replaced, this car had (seemingly) full power and revved to redline, and immediately after the cats were replaced it has major power loss and won't rev to redline?

ryalex

Yes. Do you have any ideas? Have you seen this before?

ryalex

The car is a MY 86, the water pump now is too. The one removed said '84. You would go and put an 84 on it instead?

ryalex

Alright, so since buying we have done:
- Timing belt
- Water pump
- Carl's 928MS "tune up kit" (distributor caps, sparkplugs, etc)
- Rebuild calipers
- new brake master cylinder
- brake booster valve
- complete bleed of brake lines (multiple times)
- rebuilt calipers
- new pads
- machined rotors
- shifter cup joints
- conversion to R134 A/C
- used but better condition MAF from Ducman82
- stopped the fuse #24/wiring short and beeping, found under the driver's side trunk release
- shop vac'ed out one nest under the manifolds and cleaned out the air intake which was muddy
- K&N filter
- several new fuses
- tighten floppy steering wheel
- de-cat, straight pipe
- removed stock muffler for a Flowmaster 10 (now race-car-loud) with a single rounded rectangle tip (I like the tip since it fits the shape of the rear of the car, but I think I need to go back to at least a "40" line muffler)

It's back at Carl's Place and they are doing some stuff with the fuel lines at the tank, and they trouble shot the power loss down to: a failed throttle valve. That would be in line with the symptoms of it failing to rev past a certain point and just running out of power no matter if the pedal is 1" or 3" pressed down.

Non-essential wish list:
- 17" BBS Sport Classics
- New stereo and speakers
- Dent removal for two fender dings, buff a few scratches
- new lining for sides of trunk area
- dark tint
- Foreseeable obstacle to above: wife wants new furniture already!

SMTCapeCod

I'm familiar with Holley and Rochester throttle valves...where is the EFI throttle valve? Throttle switch?

Stay dilligent with the list.
Can be very depressing when hindsight kicks in, but also important should you have future discussions with knowledgeable potential purchaser.

ryalex

I can't remember if it was switch or valve exactly.

Actually I'm not depressed about this - I did know the car needed mechanical work and was stored 14 years - but I'm starting to get close to my target number I had in mind for repairs, and I certainly didn't plan on it taking two months. My goal was always to fix it and daily drive it for a few years.

ryalex

Well four days of labor costs later and we haven't found the power loss cause. replaced a sticky throttle, cleaned, tested and tightened the whole fuel system, new O2 sensor underneath, tested coils, MAF, brains, rechecked timing, etc. Now I'm getting bummed out as we have gone well past what I thought was a generous (60% of the damn purchase price!!) maintenance and repair budget.

tv

You need to take the Gnome up on his offer!

If that doesn't do it with KNOWN good brains/MAF, then it is in one of a few items. There was a thread here years ago from, I believe, one of the nice Vegas owners with the supercharged 928 who had a similar mystery that turned out to be an exposed wire in the harness in the area that was still covered by the bundling material.



(your budget seems to be spent a LOT on labor not so much on parts, that is atypical)

M. Requin

Having missed this the first time around, I want to repeat what Dan H. said:

REPLACE ALL FUEL LINES NOW

You've done a major amount of maintenance, but until you've done this you have a car you should NOT drive. It's not a good idea, it's the only idea until you have done it. And I bet you will agree after you have seen what condition your old lines were in (and note, external appearance is entirely irrelevant).

ryalex

Back again from Carl's last night. They put in:

- Heater valve (throttle)
- seals
- throttle switch
- idle control valve
- the 'pre-cat' 02 sensor
- 928 Intl rebuilt MAF
- fuel filter
- fuel screen
- fuel pressure regulator
- fuel pressure dampener
- fuel damper
- new fuel pump
- cleaned and reattached lines
- drained tank
- cleaned fuel rails 2x
- checked Temp II and sensors at block
- multiple ohm reads for wiring on all fuel/ignition and sensor systems, everything checked out fine except certain throttle parts as replaced above
- checked w/ test EZK and Jetronic (both of the fuel brains, the original and the replacement I bought were fine)
- removed and cleaned fuel injectors
- re-checked timing on new timing belt (was fine)

Still not right, although much smoother.

It will now rev to about 4k RPM in gear instead of 2500, but it's still missing half/most power and has a flat spot between 2-3k RPM. At its worst last month 0-60 was taking about 16 seconds and now that's down to about 12 (when I bought it it was strong and around 6 sec). My faith is being tested since I have now spent the purchase price over again... and I didn't buy a ratty $3k car to start with. I was hoping to have some left over to put in a new stereo and used wheels.

Next up they want to do the fuel injectors, even though they 'tested' fine by turning over on the tester, they might be clogged or streaming. I am debating taking it back to the muffler shop too to have them check or remove the silencer as maybe that is what is clogged even after the OEM muffler and cats were removed. Recall that a few weeks ago, the three mechanics who have seen the car all thought that a clogged exhaust might be the problem.