Hi guys, I’m having some problems getting my 928 to start. I started a project in October, so far I have: replaced motor mounts, steering rack boots and bushings, refinished intake and valve covers, refurbished injectors, replaced vacuum lines and sparkplug wires, caps, rotors, valve cover gaskets, camshaft end seals, and oil pan gasket and more.
I haven’t been able to work on it until recently because of school and a new job. I have it all put back together but cannot get it to start.
My symptoms are:
1.the fuel pump wont energize
2.no spark (checked with a timing light)
3.fuel injectors aren’t firing

I have double checked all my electrical connections. I replaced all the number 53 relays that are on the panel. When I bridge the fuel pump relay the fuel pump runs. Could it be the Crank position sensor? My roommate, who was helping me, removed the CPS when we had the engine out. It had some metal shavings on it (I assume from the starter). Could this have damaged it? Are there some tests I can do to see if that is my problem? Here are a few pics of my engine. Thanks for your help in advance.

 

Did you try putting the engine in the car?

The Crank Position Sensor is what came to mind first. The shavings won't hurt it. AFAIK, there's no way to test it, without an oscilloscope.

With the S4/EZK, they went to a toothed wheel with fewer teeth, for better resolution. (Same with the ABS wheels w/86.5.) So the EZF pickup has to be in top shape, I reckon. I want to replace mine as a preventative measure.

 

Funny, yes the engine is in the car. I didnt mean the shavings, I wondered if it is common for the CPS to break when removed?

 

PorKen has a point. After you install the engine, you might consider the cold sensor idle valve (or whatever they call it) It may make a difference. It did on my '85. That and making sure there are no vacuum leaks and my '85 will crank anytime, anyplace. Even if it sits a month.. Even at 5 degrees below zero in pops to life almost instantly after sitting a couple of weeks. All my other cars hesitate a bit in this really cold weather we're having right now. Fuel pressure valve? Fuel filter plugged? Relay sticking? Fuel pump? There may be another half dozen possibilties too. Bad gas?

You have a cool looking engine, BTW.

Harvey

 

The sensor in the first pic, above, still attached to the engine, is unncessary, BTW. It was used by the factory for a TDC signal, but no-one else uses it. I removed it. The one on the bell housing is the important one.

 

Ok just to clarify the engine is in the car (see pic)

Hughett, before I worry about the Fuel pressure valve, the Fuel filter plugged, and bad fuel pump. I first need to find out why the fuel pump won’t activate. I replaced the relay, and the fuel pump will not run. If I jump the relay it does run. On top of that I have no spark or injector pulse.

Porken, isn’t the sensor on the pic the cps? The sensor (not shown) on the bell-housing is what the testing equipment attaches to on the top of the engine.

 

Pull that motor and just encase it in glass, put it in the living room and you will have the nicest piece of art in the neighborhood.

 

Uh... just checking to see if you were awake! You're correct, the sensor on the bell housing is superfluous.

The EZK sends a reference pulse to the LH. No pulse, no fuel injection, no fuel pump relay.

 

What about spark?

 

And no spark.

 

Well I think I know what part Im buying now

 

You replaced all three relevant relays. The CPS is the first suspect. Like Ken said, I don't think you can test it without an oscilloscope to see the pulse. Quite often the connector fractures with age. Which reminds me - I need to order a new one for my 89. The current one is being held together with zipties.

 

SeanR, thanks for the complement. Right now my only wish is to see that "peice of art" run instead of being a giant paperweight.

 

You can test the CPS using an analog volt meter set to a low AC scale. Watch the needle deflect up to 5v on cranking. This will only tell you if the CPS is receiving triggering voltage.

p.s. does the car have an factory alarm? It will also cause your symptoms.

 

Thanks bill. The connection looks fine, but on my sensor where the wire goes into the sensor, it looks like the white plastic houseing is cracked. Maybe thats the problem.