fraggle

So you are getting spark but no fuel. This means the cps is ok. There's something else wrong, either between the two brains of in the lh itself.

I just posted in another nostart thread about the blue/white wire on plug W on the cel.
You should be able to detect a squarewave there. It heads through interior wiring to the tach, such that if there's a short somewhere, it pulls the signal to a flatline.

ZEUS+

Check for shorted wires at injector connectors. Very common and will shut down LH causing no injector pulse.

borland

WSM provides specific test points for troubleshooting. Look in Volume 1A.

John Speake

I didn't notice is is a 5 speed, but also I have known that in the process of fault finding, a normal relay has been plugged unintentionally into the (vacant) kick down position, which shorts out the rpm pulse from EZK to LH.

Rod Underwood

Great, I didn't see this, but it will be our next attack! Probably this weekend or early next week.

Thanks

Rod

victor25

What ended up being the fix for this????? Having the same problem. I am afraid my EZK is bad

dr bob

Victor--

lots of sensors need to work just right, or it will look like EZK failure. All the sensors listed previously in this thread, plus the EZK relay too. You can sub the horn relay into the EZK socket for testing. EZK has a fuse tester but is otherwise a standard relay.

victor25

Hi dr bob
yeah I am pretty sure it's the EZK, but not 100%, hate to spend the cash untill I know for sure. I have done lots of tests already. The relays work fine and have changed them around to make sure. The car will start for a second when cold, but then dies. If I then jump the fuel relay then it will start again and run for a while, but eventually things go funky and it dies again, then it wont start at all and has no tac, but it is getting a pulse form the CPS. If I go back the next day the process starts all over again. One of the big signs for me, is that my shark tuner won't communicate with it I have been playing around with a bunch of stuff on the car lately (added a wideband, fuel pressure sender, upgraded the LH, etc etc..... and thinking I have fried the EZK in the process because I didn't disconnect the battery and was using a charger. I didnt realize how sensitive they were untill now... lesson learned!!! it's not a Ford LOL

John Speake

The EZK ECUs are pretty rugged, much more so than the LH. Double check for spark again, work through logically...

victor25

Hi John
I will start the process over today, but I just put the LH in a couple days ago, and its one of your repairs so I think it's fine. Here is what I know so far.

I have spark
the fuel relay does not engage
the EZK will not communicate with the Sharktuner
if I jump the relay, the car will start after a few tries and seams to run fine.
I noticed the tac does not move when trying to start it but then it fires and the tac jumps into action
once the car is hot, if I shut it off, it will not start again untill it cools down.
the fuel relay never works and I have switched it around many times

here is some questions for you. what pin numbers are used to communicate with the EZK (at both the diagnostic cable and the EZK plug). I would like to try going direct from the EZK to the tuner to eliminate any bad wires. Its like the EZK is weak on power, and not sending enough for the LH or the Tac to fire them up. Also the if I give it more than 1/2 throttle it tends to missfire

What do your think?

victor25

Also when the when the EZK was working with the shark tuner, if I clicked on the ezk monitering page the lights lights for the hall sensor and others would stat flashing and doing weird things, and the car would run very rough untill I clicked back off that page, then it would run ok again again.

John Speake

Hi Victor,
I believe that Louie has offered to test your LH and EZK in one of his cars. This could bypass lots of fruitless investigation on your part. The ST2 probably isn't going to give you the answer you require until the problem is fixed :-) Catch 22.

You could try refitting the stock EPROM in the EZK ?

victor25

yeah I thought about putting the stock chip back in to see what would happen. Personally I dont think it will make any difference, but its worth a try.

victor25

Hi John First .. I walked out back tonight and started the car like there was nothing wrong. It had been sitting for a few days, I turned the key and she started right up. I drove around the block a couple times then pulled back into the shop and turned it off. I then turned the key again and same old thing, no start, and no fuel pump.
Second .. I changed out the EZK PEM back to the stock chip and no change, same thing. It will start after a few tries if I jump FP relay though.
Third .. I found an 88 s4 EZK, will that work in my 89 s4 5spd

John Speake

ECU's almost never fail intermittantly.... so sounds like a wiring contact or relay problem.

Carefully check there isn't any corrosion on the pins of the LH ECU. A favourite one to get rotted is pin #1 which is where the rpm signal from the EZK goes to wake up the LH ECU (turn on fuel pump, injectors...)

I assume you have swapped out the LH relay for a known good one... what circuits does your imobiliser act on ?