Ran out of gas 5 months back, hasn't run right since...thoughts?

MarkRobinson · 05-14-2008, 07:46 AM

My incredible accurate fuel level gauge in my 914 left me stranded with a 1/4 tank of fuel indicated left in the tank, some 5+ months back.

Since pouring in more fuel in to re-start the car, it was not running properly, as if I dislodged something in the tank & clogged the filter.

I changed out the filter ( a rather large aluminum one about 6oz or so) but no go, so I pulled the injectors & back-flowed them to check for debris: still nothing fixed.

So, I pulled the points, replaced with an optical, hooked up an MSD 6a & blaster coil, & set the timing. Now, I have a very, very weak spark: idles on 4, but only drives on 2/3 cylinders depending on how it feels.

In diagnosing this, I removed the MSD & put the stock coil back on: much of the 2/3/4 issues are gone until it's warm, then they return. Barely got my car into my garage (uphill driveway) last night as it was only running on 2 cyl.

considering replacing the points (to rule out the optical) & put the MSD back on: thoughts?? Frustrating..I need to stop driving my much more expensive & rare Porsches, esp. during this inclimate weather-time of year.

Mark

vacca rabite · 05-14-2008, 08:16 AM

Sounds more like a spark problem the a fuel problem.

If you pull an injector with the pump running, will it spray fuel? have you checked fuel pressure? Best to be sure, I guess.

Are your plugs in good shape? Put new points on? Replace your plug wires? Check your grounds. make sure that the tach wire on the coil is not cut and grounding out somewhere?

zach

Zach

MarkRobinson · 05-14-2008, 08:27 AM

I haven't checked fuel pressure lately, but set it to 28psi or so 8months back.

I have fresh plugs (checked 2x for mixture), Kingsborne Beru wires, new cap, rotor, Optical pick-up (points replacement), MSD & Coil (temporarily disconnected), & have not cleaned the ground wires recently: where are they for the ignition system/ECU? In the fuse box? I've cleaned terminals in there before...

Mark

vacca rabite · 05-14-2008, 08:41 AM

Engine grounds, there are three of them. The first is a wide ribbon cable that connect the top of the tranny to the bottom of yout trunk. Then there is the ground at the (-) battery to the car body. And I thin that there is also a ground near the alternator.

The ribon cables get tired and break/get junk in them. bad ground could equal weak spark. Check and clean, or replace if needed.

Zach

R_Davis · 05-16-2008, 11:00 AM

Hey Mark,
Don't want to sound like a broken record but lemm throw some stuff at you. I had similar problems after running on fumes a while back. Obviously there is stuff in the bottom of the tank that can break loose and migrate.
This may not work for you, but it worked for me.

* I put a good amount of Lucas Injector Cleaner in the tank and took my car to a good, clear & safe? highway and ran the car a little harder than normal until everything kinda opened up.

* I also had an issue with my new wires. While they looked good, there was a problem with where the wire met the boot on the plug. It had pulled loose all by itself

* I found which wire was the problem by hooking up my timing light to each wire and reving the engine to around 3600 RPM or so while just holding the trigger on the light and watching to see when and where it didn't flash.

I think it's a spark problem.

Go figure ... Last night I replaced a bulb in my dash and now my radio won't turn off! I had to disconnect the battery! Sheesh. I expect to choke to death on a defective toothbrush any day now ....

Good luck,

Rick

MarkRobinson · 05-16-2008, 11:12 AM

I replaced the plug wires a long time ago (kingsborne) & didn't have issues before I ran out of gas: the car was running really, really well until then

I'll try the cleaner, but converting back to point this weekend to see if there's something up wiht the optical pickup.

Mark

MarkRobinson · 05-19-2008, 08:13 AM

K, I'm now starting to suspect my new plug wires: I continue to have what feels to be a very, very weak spark on #1. I removed my optical pickup & replaced the points, but the weak spark continues.

I say weak spark because I've cleaned the entire fuel system including removing & back-purging the injectors, regulator, etc. My #1 plug was fouling (a few weeks back when I first checked) & I need to see if it still is...& I should swap the injectors (1&2) so that I can eliminate the injector as a culprit (excess fuel or semi-stuck open).

I'll re-hook up the MSD tonight & see if it that changes anything, but with the optical removed & the points back, I suspect the wire now.

Are there any other ignition components besides: Points, coil, cap, rotor, wires, plugs?

SGB · SGB's Garage

I gave up on magnacore and went back to Bosch, I haven't tried the Beru ones, but Magnacores would not stay attached to the plug.

MarkRobinson · 05-22-2008, 05:07 AM

The Kingsborne are excellent products: they snap onto the top threaded part of the plug (3/32" female with wire clip). Still, I'll move the leads around a little to see if my weak spark follows it around.

My thoughts: my spark is generally very weak, so the longest lead offers the most resistance (assuming spiral-core resistance wires & not solid core).