ammonman

Good spark but no FP signal from the LH and no running even when the FP relay is jumpered to force the fuel pump and confirmed 12V to the LH sounds to me like a failed LH. f you have a Noid check and see if the injectors are firing while cranking or swap your LH into a known good running car and see if the symptoms follow the LH. If the injectors are firing but it won't start then I think you would smell a lot of fuel in the exhaust.

Mike

kmascotto

Thanks Mike, the noid light is the only test i haven't done. That said, i know a local who's car i am hoping to use again as a tester for the LH.

However im still open to opinions, if there is something ive missed

John Speake

Did you see the signal to pin 1 LH flicking up and down as the engine was cranked ?

kmascotto

John, the DVM read 8 volts. I didn't notice any fluctuation in the numbers. I suppose that maybe my DVM couldn't keep up with the volt changes.

Thoughts?

John Speake

I would have thought that at the low cranking speed you should see it flickering up and down. 50rpm would give two distinct voltages 0 and 12v in a period somewhat longer than 1sec. I would have thought that would be visible.

You could try the meter on a.c. volts, you will get an indication the volts are changing when cranking.

Depending on the filtering for rms conversion you should see 3-4v a.c.

kmascotto

Well, with the trouble shooting help of Colin (Lizard) in Vancouver we got it started (Thank you Colin!!!). The issue was the tach wire!! Once the tach wire was unplugged from the system, it started.

Thanks Jeremy, you called it

Thank you all for the help

dr bob

Kent--

Glad you got it running. Do the rennworld a favor and share where you find the fault in the tach circuit. There isn't a lot to that, but this isn't/won't be the only time this comes up. So I can add your finding to the list of diagnostic steps.

kmascotto

Will do, ill update with a pic shortly

kmascotto

The only way to diagnosis the Tach fault, is to unplug the Tach wire from the CE panel. The tach wire is in plug W, which is located in the last plug connector on the bottom right side of the CE panel. Pull the plug out and split the plug in two. I used a very small flathead screw driver.

The wire (Blue/white) is in the red plug in plug position #1 (the number 1 is very small and hard to read) its the blue and white wire which is next to my thumb. Unplug the wire by pushing it out of the plug and wrap the connector with a little electrical tape and leave it aside.

Next, just put the plug back together and plug it all back in...and try starting the car.

kmascotto

My next step will be to source a good used 89 instrument cluster for parts to fix my tach issue. Until then...no RPM gauge

erioshi

While the cluster is the most likely source of the problem, were this my car, I'd also check the continuity and resistance of the wire between the CE panel and tack, just to eliminate that wire as the potential source of the problem.

The wire between the LH and CE panel would seem to have eliminated itself from the list of potential problems when the car started.

dr bob

Kent--

That wire would have to fault to ground to disable the tach and the LH. Next time you have the multimeter handy, could you check Ohms to ground on the wire you disconnected? If that shows the fault, we can revise the diagnostic step to check that wire with the meter before disassembling. It wouldn't define the location of the problem without disassembling as you did, but it could rule it out if the meter reading isn't low, saving the disassembly steps.

I'll make a note to check what the meter reads on my working '89 and compare with what you find. The car and I are separated by a country right now.

kmascotto

Will do. I'll post when I get the info.

kmascotto

Update: I checked the Tach wire for Ohms to Ground. With the meter set on 200k Ohms (checked at zero) the reading was 10.1 Ohms.

Lizard928

As his car reads 8-10V on pin 1 of the LH while cranking with no fluctuations. The problem is not a grounding issue, but a popped circuit in the cluster most likely.
If it was grounding, then there would be zero voltage at pin 1 while cranking.
The only options are a short to positive, which should then be 12V, or a problem in the cluster which can add any variance in voltage due to resistors etc.