Car Won't Start, but Starter Turns

[Georgie]

There is no voltage to the fuel pump. I have been going through the troubleshooting steps in the Bosch fuel injection troubleshooting manual.

On step 11 check voltage input to relay set from the ignition switch, rather than the 12v, I get closer to 9.5v. I get about 10.5V from terminal 86a to ground. The large brown wire has 12.5V (88z). I have checked the wires to the ignition switch and they seem ok. Fuses all show continuity.

It was stored in a friend's barn over the winter. Fired right up when I picked it up. Drove home perfectly. When I later tried to start it, it seemed a lot of the electrical components didn't work, including the fuel pump. A friend suggested the ignition switch, given multiple things seemed to stop working.

Any ideas? How do I test the ignition?

Thanks,
Phil

[18Fiatsandcounting]

As far as testing the ignition, the easiest way is to connect a timing light (any plug wire will do), and it should flash when the engine is cranking. If you don't have a timing light, the next easiest way is to remove a spark plug, reconnect the plug wire, and lay the metal part of the plug against the camshaft cover. Cranking the engine should result in a spark every second or so, depending on cranking speed. This might require two people: one to turn the key and one to look for the spark. But, in a relatively dim location with the spark plug angled right, I can usually turn the key and look for the spark with just me.

Don't put the spark plug too close to the hole that it came out of, just in case fuel vapors are pushed out through that hole when cranking, as you don't want these vapors being ignited by the spark plug laying on top of the engine.

If your ignition looks OK, then we'll have to do some more diagnostics to determine why the engine won't run.

-Bryan

[tima01864]

I think everyone would agree to clean off all the grounding points and wires, loo at the connections at the relays under the dash.

[Georgie]

Hi Bryan,
Thanks for your reply. I should have been clearer, I meant "how do I test the ignition switch?"

I am most suspicious of the lower than expected input voltage to the relay. I am expecting 12V but it is closer to 9.5V.

Thanks again,
Phil

[Georgie]

@tima
I saw an article that talked about replacing the connectors on the wiring, I am also considering that, as tracing down all the wires is frustrating.

I will start a with the grounding points. I have been checking all the connections to the relay.

Thanks again for the advice. I sincerely appreciate it.
Phil

[tima01864]

i saw in a previous post recently, that gave a link to wire diagrams at Mirafiori. Those should point out the grounding points and locations. Seems odd it all went at once, After the car had been running.

[18Fiatsandcounting]

Phil, sorry I misunderstood, and yes, I immediately jumped to a conclusion that I knew something about (ignition system) to something that can be a lot of smoke and mirrors (ignition switch)...

Let's go back to your first post: When you say that you "tried to start it", what were the symptoms? Did the engine crank? Dash lights come on? What else?

The reason that I ask, and this is a long shot, but I once had a Fiat which had enough battery juice to get the car started, but the battery was basically on its last legs, and that one time of starting the engine pretty much finished it off. At that point, the battery could turn on a few dial lights, but anything more than that, not so much. Anyway, make sure your battery is good, or connect some jumper cables to a known good battery as a test.

-Bryan

[Georgie]

Thanks all. I am heading out to troubleshoot now. Some family stuff came up and I had to make a couple of impromptu trips. Hopefully I can get to the bottom of this. I will chase down the grounds. A fun afternoon is in store!!

[NGK]

I have a similar problem but mine will start it just won't run Ive traced the problem to my fuel injectors which weirdly have two positives on them and aren't getting a ground signal or negative charge try pulling off one of your injector connectors and see if you have power to those while you crank the engine.

[aj81spider]

I believe the way the injectors work is that the double relay powers them (one of the wires and positive voltage you are seeing). The ECU then briefly grounds the other side of the injector to fire it. If you are looking at the wire that goes to the ECU with a meter it will not appear to be ground because it only blips low briefly.

You may or may not have a problem with your injectors, but I don't think pulling off the connector and looking at it with a meter will tell you that.

[RRoller123]

Yes, the injectors fire by grounding. Per the manuals. Need those "noid lamps" that can rad the small signal and flash. (I think that is what they are called. )

Here are some great manuals:

FUEL INJECTION DEBUGGING
http://www.hiperformancestore.com/Ljetronic.htm
http://www.njfiats.org/joomla/images/st ... BoschL.pdf

FUEL INJECTOR CLEANING:
WWW.OKINJECTORS.COM
www.witchhunter.com

FUEL INJECTION MANUAL
http://www.mirafiori.com/faq/fiatFI_may2002.pdf

FUEL INJECTORS CHART
http://users.erols.com/srweiss/tableifc.htm

L-JETRONIC MANUAL
http://www.hiperformancestore.com/Ljetronic.htm

L-JETRONIC
http://mastertechmag.com/pdf/1988/11nov ... ronic2.pdf
http://jenniskens.livedsl.nl/Technical/ ... tronic.pdf

L-JETRONIC FI MANUAL (FROM VW)
https://www.type4.org/manuals/ljet/index.html

BOSCH L-JETRONIC MANUAL – BEST ONE:
http://foxed.ca/rx7manual/manuals/BOSCH ... Manual.pdf

http://dtec.net.au/Tech%20Articles.htm

[spider2081]

I have a similar problem but mine will start it just won't run

Often an engine starts but will not run if there is an air leak located between the airflow meter and the throttle body ( intake manifold. Pretty common for the large hose to have cracks causing the issue.

A simple way to check if injectors might be working is to listen to them. Place a long screw driver on the injector near the connector, place your ear on the handle of the screw driver. Have someone crank the engine. If the injector is pulsing you can hear it in the screw driver. The 4 injectors should sound similar.

[RRoller123]

Yes! They give a very clearly audible "click" when they fire. I haven't tried it with a screwdriver, but it is very clear with a cheap HF mechanic's stethoscope.

[DieselSpider]

Yes! They give a very clearly audible "click" when they fire. I haven't tried it with a screwdriver, but it is very clear with a cheap HF mechanic's stethoscope.

Those cheap HF mechanic's stethoscopes work very well and sometimes are a bit too loud. I also use mine to detect the sounds of leaks in pipes and roofs and have even been able to hear vermin crawling around in walls in some homes using one.

For something that costs less than $4 they work surprisingly well.

[filipm]

Well, my dad and I bought Fiats last summer and his is experiencing the same symptoms. Starter cranks, car won't start.

Replaced the dizzy, rotor, ignition pickup, plugs, wires, checked all the grounds, coolant sensor wires, cold start... And it started! Drove it around for 5 minutes, warmed up, fan kicked on (it was a hot day), parked it back in garage, turned it off, tried a warm restart (no problem). Thought we golden. Came back 30 minutes later, no luck. Cranks, no starting.

Started to diagnose and looks like there might not be spark coming from the coil. Searched a bunch and read that ignition switch could be the culprit. I should be able to see 12+ volts at the pink wire of the coil with the ignition keyed to on right? I was thinking maybe it was the ICM but now leaning towards ignition switch. Either way... looking for a resolution to take advantage of the weather!