S4 not starting at all....

[Niles]

It seems like it has to be timing - either the cam timing or the distributors. Are the rotors pointing in the correct direction when it's at top dead center? I'm trying to remember on mine, but it seems like the rotors can be positioned in one of three possible positions each.

The other item that came to mind was the crank position sensor, but I'm not sure what the symptoms of a failed CPS are.

[Yellowb1rd]

Originally Posted by Niles

It seems like it has to be timing - either the cam timing or the distributors. Are the rotors pointing in the correct direction when it's at top dead center? I'm trying to remember on mine, but it seems like the rotors can be positioned in one of three possible positions each.

The other item that came to mind was the crank position sensor, but I'm not sure what the symptoms of a failed CPS are.

CPS is fine, as it's sending a signal to the shark tuner. It is true that if a CPS goes bad, the car will not likely run at all. I don't think it's timing, as the car starts up promptly with a shot of Ether.

[Niles]

Yeah, but almost anything will run on ether. Running on ether proves it has spark and air, but it does not tell you if the timing is correct or if it's getting a strong spark or getting enough air. Gasoline does not ignite so easily.

[Mrmerlin]

from the ether report we know the timing is good otherwise it wouldnt run.

What is missing is fuel so you have an injector issue.

BTW more info requested.

Please describe exactly what year engine and year harness went into what year chassis and CE panel ,

since every model year engine wire system is slightly different,

a plug and play version approach may not work as you think it should.

after you answer these questions it will make it easier to figure out where to proceed

[Yellowb1rd]

Originally Posted by Mrmerlin

from the ether report we know the timing is good otherwise it wouldnt run.

What is missing is fuel so you have an injector issue.

BTW more info requested.

Please describe exactly what year engine and year harness went into what year chassis and CE panel ,

since every model year engine wire system is slightly different,

a plug and play version approach may not work as you think it should.

after you answer these questions it will make it easier to figure out where to proceed

Hey, Stan.

The replacement motor is a 1990, and the car is a 1989 with original CPUs, as far as I can tell.

[tisilrad]

a failed crank sensor would give no spark, the EZK is the master here and gets the signal from the CPS and then sends a signal to the LH fuel controller, so in this case if you are getting spark then it is not the CPS. Check to see if the LH is getting a signal from the EZK . Keep in mind that this could be a wiring harness problem, i would also check continuity of the three wire cable from the CPS to the EZK. There should not be any continuity between any of the individual terminals...i had this problem with mine and had to run a new CPS to EZK sheilded cable to correct mi intermittant no start and stall issue..
For your car im still skeptical about cam timing, especially if you have not had the timing belt retensioned after the recent work

[Yellowb1rd]

Originally Posted by tisilrad

a failed crank sensor would give no spark, the EZK is the master here and gets the signal from the CPS and then sends a signal to the LH fuel controller, so in this case if you are getting spark then it is not the CPS. Check to see if the LH is getting a signal from the EZK . Keep in mind that this could be a wiring harness problem, i would also check continuity of the three wire cable from the CPS to the EZK. There should not be any continuity between any of the individual terminals...i had this problem with mine and had to run a new CPS to EZK sheilded cable to correct mi intermittant no start and stall issue..
For your car im still skeptical about cam timing, especially if you have not had the timing belt retensioned after the recent work

Thanks for the input. Timing belt does not need to be re-tensioned, as I've replaced the the original unit with a 'Portensioner', which is self adjusting. Also, even if it were the original unit, it's never been started (other than a few moments with Ether), and generally speaking, with the factory unit, you need to re-adjust after 1000 miles or so.

[Yellowb1rd]

Originally Posted by Mrmerlin

from the ether report we know the timing is good otherwise it wouldnt run.

What is missing is fuel so you have an injector issue.

BTW more info requested.

Please describe exactly what year engine and year harness went into what year chassis and CE panel ,

since every model year engine wire system is slightly different,

a plug and play version approach may not work as you think it should.

after you answer these questions it will make it easier to figure out where to proceed

Hey, Stan.

The replacement motor is a 1990, and the car is a 1989 with original CPUs, as far as I can tell. Any other ideas as to what I can test?

[Mrmerlin]

I was thinking that you should ask Alan he has the best wire diagram resource, my diagrams are in the trailer

[Yellowb1rd]

I've found these coming from harness close to the back of the fuel rails on each side. Are these temp sensor connectors (exhaust)? There are two total (one on each side), and I have not been able to see where they connect. I'm hoping this is the issue.




Not at the car at the moment, so I cannot verify. I could use some insight from anyone who knows exactly what these connectors are. Do these connect to the needle-like sensors that are inserted into each exhaust manifold, and would these prevent the vehicle from starting? Photo is upside down, BTW.

[neil30076]

IIRC, those are test points and do not connect to anything but diagnostic equipment.

[Mrmerlin]

please send Alan a PM he will be able to answer your questions

[tisilrad]

Ok i have reread the entire post. Some additional suggestions would be to check your ground connections under the dash above the central electric panel. The LH grounds the injectors to fire them, HOWEVER, it could have a loose ground that will cause a drop in voltage due to increased resistance. A voltage test with a meter would be using a ground from the lead..thus showinng 12.5 volts. The small voltage would also be enough to fire a noid light but NOT have enough voltage to open the injector coils. So long story short..check your grounds, possibly the one at the back of the motor, in the same area of the throttle cable and crank sensor(...im not sure where the ground for the injectors are at), look in the wiring diagrams if you have them.Also make sure the primary ground from the engine block to the chassis is clean and tight,if you changed the motor this would have to come off...possibly not tightened up well enough. The grounds on the engine block depend on this primary ground(i replaced mine with a 00 sheilded cable.)

[tisilrad]

I need to learn to use spell check...sorry

[Yellowb1rd]

I've tested the injectors individually (by routing from the car's 12 volt power source on the front passenger side) by providing power and ground. No clicking at the injectors. Ive run the same test by on a connector at the harness to get them to all click at the same time. I've checked all ground points, replaced relays, tested fuel pressure at the rail, etc etc, and the injectors are absolutely not pushing fuel into the cylinders. What are the chances of having EIGHT bad injectors???!!!

[Yellowb1rd]

Ran additional tests today on the installed injectors, and have found that only one out of eight is clicking. Then I merely connected one of the original stock injectors to one of the injector plugs, and while holding it, reached into the cockpit and turned the car over. I could feel the injector selenoid opening and closing because it would contact my fingertip very lightly. The point is, gentlemen, that I plugged a known working injector into a connector connecting a known malfunctioning injector (well known now), and where the replacement injector did not fire, the original did. In a nutshell, most all of the injectors are bad. I don't know what the chances of that are, but maybe I should purchase a lottery ticket. When I install the replacement injectors, I'll let everyone know the outcome. I appreciate the very helpful insight from you all. I think we've got this one licked...

[tisilrad]

the chances are slim you have 8 bad injectors, but not impossible, did you check the resistance of the injectors..should be 11-15 ohms.If the entire set was replaced they may be the low impedance versions. I cant help but think there is something small you are overlooking. I would start over from the beginning and test each component necessary for running. Fuel/spark/timing/compression. I wish i was there

[Yellowb1rd]

Originally Posted by tisilrad

the chances are slim you have 8 bad injectors, but not impossible, did you check the resistance of the injectors..should be 11-15 ohms.If the entire set was replaced they may be the low impedance versions. I cant help but think there is something small you are overlooking. I would start over from the beginning and test each component necessary for running. Fuel/spark/timing/compression. I wish i was there

BTW, I love your signature about your 928 being a money pit. Brilliant, mate! Certainly true in this case as well. I tested the resistance on all injectors, and they were consistently reading 16 ohms, which is expected from these 36LB injectors. But today, I tested each one individually using a battery charger as a power and ground source at 2 amps, and I could only get one to click. However, with the same test, I could get all of my OEM injectors to click. I love the support from the 928 bunch! If it weren't for the help I've received on this forum, I would have sold the 928 long ago.

[Mrmerlin]

its possible that your new injectors have setup with the old cleaning fluid thus possibly jamming them, one vender on Ebay suggested to use a 9 volt battery to test the injectors prior to installing them, as sometime the injectors will get stuck.
so this is quite possible
If you used a noid light and it is blinking then the injector not opening is the next link

[Danglerb]

I've seen a car with 8 stuck injectors, lets just say it was "not" an inexpensive "tune up" getting to that point and replacing them.

Once an injector has fuel in it, removing it and allowing it to dry out can cause sticking, via dried junk, but also from rust.