Alfa Romeo Forums banner

1 - 8 of 8 Posts

·
Premium Member
Joined
·
21,491 Posts
Discussion Starter #1
In continuing to work through my 89 Spider, it starts poorly cold, fine hot. I did some diagnostics yesterday (60ish degrees, car stone cold), and came up with:

* Coolant temp sensor: measures 2.76 ohms (spec is 2-3 ohms)
* Thermo time switch: measures .04 ohms (spec is 0 ohms)
* Cold start injector: did not fire any fuel at all on several tries of turning starter

My questions: With the TTS out of spec this small amount, is that enough to make the CSI not work at all? Is it an absolute? If so, maybe I need a new TTS?

Or do I have a bad CSI? I cleaned the contacts on the TTS and the CSI with no change. Is it possible to test the CSI off the car? Does it have an ohm range? Can you send 12V to it to see if it squirts? Perhaps you'd need fuel pressure behind it to get it to function?

Any help appreciated. Thanks

Andrew
 

·
Registered
Joined
·
146 Posts
I'm pretty sure I'm not telling you anything new here, but just in case, try this site:

http://www.hiperformancestore.com/Ljetronic.htm

Also, you will see an assortment of other L-Jet tech sites, albeit for other lesser cars, if you Google it. Regardless of the marque, it would be reasonable to think that the system itself would be pretty much the same.

Hope this helps.
 

·
Premium Member
Joined
·
21,491 Posts
Discussion Starter #3
That's what I was working from. It doesn't go into further detail on testing the CSI. I just noted that in testing the injectors you're supposed to have 2-3 ohms across the terminals. Would that be the same for the CSI?

Andrew
 

·
Premium Member
Joined
·
21,491 Posts
Discussion Starter #5
Thanks. Do you know if you can hook it up with 12V directly to test its function? Or is that too much juice?
Andrew
 

·
1966-2013
Joined
·
13,741 Posts
You can, but only for a very short time, like just enough to make sure it clicks.

The voltage itself isn't too much, but lack of fuel flow to cool it and that it only stays on for milliseconds anyway means it's more than possible to burn up the windings inside with prolonged power supplied to it.

It may be more to your benifit to actually remove it and do a spray check instead. (IIRC, there's info on that at the L-jet page, and if not, the main site for sure)
 

·
Premium Member
Joined
·
21,491 Posts
Discussion Starter #7
I re-measured my TTS and CTS with new batteries in my multimeter and think I need to replace them. Off the car, the CSI functions when given 12V, and I made a gas standpipe out of a long piece of hose, filled with gas, and while the CSI didn't exactly spray with such minimal pressure, it did dribble, which it wasn't doing on the car. So I'm assuming the CSI is good and the sensors are bad. We'll see.

Andrew
 

·
Premium Member
Joined
·
21,491 Posts
Discussion Starter #8
I passed smog with this car yesterday, so running for some period with zero compression on one cylinder didn't seem to have hurt it too much. I installed new mid and rear exhaust pieces, and welded up a couple holes in the cat, and got these numbers:

15 mph: HC 93/124 CO .17/.78 NO 236/815
25 mph: HC 72/98 CO .17/.66 NO 151/754

First number is measured, second is max allowed. So I've got a fair amount of unburned stuff happening (high HC). It has new spark plugs, and compression is about 150 across the board. Poor oil rings allowing oil to be burned? It does have 162K on it. Cat going south? Whatever, I'm safe for two years.

Thanks for everyone's help on this.

Andrew
 
1 - 8 of 8 Posts
Top