buccicone

One of my club members' '85 5-speed didn't start this morning on the way to cars & coffee. Checked for spark on both coils. Nothing except when the key is released after cranking, there is one puny spark that occurs. It ran great last night. CPS is newer connector fine. He went through the CE panel cleaned up a few things, swap out relays still nothing. Both the LH & EZK were recently rebuilt and tested.

MainePorsche

Status of ground strap ?
Battery compartment vented well ?

Mrmerlin

replace the running relays one at a time verify your in the right slot and that the connectors in the relay housings have not pushed out the back.
Check the connectors for the computers use Deoxit 100
This sounds like a relay issue

Check and clean the battery connections and the hot post connections

buccicone

Maine Porsche: He's getting a new battery ground cable. How does venting effect things in the battery compartment? We had it open testing.

Stan: Will pass this on...........

buccicone

Keep 'um coming guys!

jbrob007

We (Mike, Randy & I) have been perplexed by this ALL DAY... frustrating as hell considering she was running well just last night. Parked the car and in the a.m. it's a "No Start" without any apparent cause (except sitting overnight). All suggestions are greatly appreciated!

Koenig-Specials 928

Fuel: You sure you're getting fuel to the front?
Remove/re-install fuel pump fuse and verify that you can actually hear the pump at the back
Then remove the fuel rail end nut (don't lose the ball bearing) and see if fuel comes out.

That would be my next move if the battery/ground and spark checks were done

davek9

I'm with Stan on the Relay, or a Fuse connection, also just because a Relay is new doesn't make em good.

Dave K

buccicone

Yes, fuel pump is running. Hear fuel circulating. No spark. I believe today he may crawl under to check ground from engine to frame.

Mrmerlin

here is why you want to check the grounds and battery connections ,
your battery is the giver of life,
the systems in the machine suck this up,

when the power is reduced then the systems will fight each other ,
what happens is that the relays that are used to transfer power to systems can sometimes not get enough power to close,
over time this is what usually damages a relay by preventing the power to transfer through the contacts.

So keeping the battery fully charged and replacing the running relays will generally provide continued performance,
Same goes for the fuses keep them clean use the IR gun to find hot spots.
make sure all grounds are clean and the battery terminals are clean and tight ,
14 pin connector as well
use deoxit 100 on the elex connections

buccicone

The wise man saith. Very true Stan. My two are always on the battery tender if they are parked in my garage. They both crank & start 100%. Looking at the way these battery ground straps corrode internally, I'm planning to replace all of mine.

Landseer

You are not the first to have mysterious, out of blue, no start on 85/6.

I guess you tried to top of battery, then foot on floor long cranks to clear a potential flood out?
That's worked for me a few times. Flood out condition just happens sometimes on mine, only correlation for me is it has happed several times after a short repositioning of the car, like moving it from one place to another on the driveway.

You can jumper relays and remove from equation 30/87. You can also monitor control voltage on cranking with meter tapping 85 and 86 on CE with relays out. Guess you probably know that.

Disconnect / reconnect battery is another thing to try. Worked for me once, probably totally unrelated, but it happened.

buccicone

Update. Cleaned engine to frame ground, battery to ground replaced, cleaned 14 pin connector. Power to relay 8. Question: If relay 8 30/87 terminals are jumped on the CE panel, shouldn't that trigger the ignition or at least the EZK to get spark at the coils?

worf928

The ECUs need high-10s of volts to work. What is the voltage during cranking as measured at the jump post (easy) or at the CE panel (harder)?

Voltage drops between battery hot post and EZK term 30 while cranking will tell you where the problem is.

Start with: What's the voltage across the battery while cranking?

Then: on to the next test point on the way to EZK term 30.

Remember: a hair strand of copper will pass 14v at 0.001 amps but not at 1 amp.

buccicone

Will test these ideas out, Dave.............