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triggering cold start

2K views 25 replies 7 participants last post by  chull53 
#1 ·
a special thanks to recent help from the AlfaBB readers and Eric Russell's tune guide.
I have tested the cold start injector works great when wired directly.
i'm on a used, but apparently tests ok Thermal Tine Switch..
cold start injector doesn't energize.
might it be the fuel ECU, or should I send for a NEW TTS?
thought are appreciated.
ALSO..i have an old thermostatic actuator from a 1750 spica for sale/make offer.
thanks to all.
 
#3 ·
i'm on a used, but apparently tests ok Thermal Tine Switch..
cold start injector doesn't energize.
what do you mean by 'apparently':)
someone told you it wass ok, or you tested it yourself?
If you haven't tested it yourself, then test it to be sure,

also check the bosch connectors on TTS and CSI, sometimes it's a simple problem whereby one of the female pins inside gets pushed back and doesn't make contact anymore

CSI and TTS Baloney
Questions re: CSI, TTS and TPS testing
 
#4 ·
Well, your injector is good, so that's good. Go through the TTS troubleshooting steps here:


Note that the W-to-ground measurement should be very close to zero Ohm when cold. I've seen older TTS parts that have built up a couple ohms resistance in this ground path. If that happens it may not allow enough current for the CSI to fire, so be cognizant of that.

Also note that the TTS/CSI are only powered when the starter is powered, not when the ignition is on.
 
#6 ·
Well, you powered the CSI directly and it fired. I would try powering it through the TTS (with TTS cold) and see if it fires like that, and then also verify that it's getting power during cranking.

(note that the TTS circuit to the CSI will open after seeing 12V for approximately 8 seconds, so if you do the first test you'll likely need to do it quick)

I'm on the road and don't have my L-Jet wiring diagrams so can't suggest how best to do these at the moment, sorry.
 
#7 ·
thanks for the interest and advice.
I pigtailed direct to my (3)TTS's. no change.
I guess I don't trust my own testing at this point.….although reading great manuals. thanks alfabb.
an easy fix? send for a (NEW) TTS?
ALL WAS FINE 'TILL I STARTED PUTTING ALL BACK TOGETHER FOR SALE!
started fine, ran ok. now no start.
cold start works beautifully straight wired.
used TTS test ok.
I need this car gone,.....trying to move residence.
i'd rather drive an ALFA, but I need all my attentions to an old HEALEY at this time.
Charlie.
 
#8 ·
a special thanks to recent help from the AlfaBB readers and Eric Russell's tune guide.
I have tested the cold start injector works great when wired directly.
i'm on a used, but apparently tests ok Thermal Tine Switch..
cold start injector doesn't energize.
might it be the fuel ECU, or should I send for a NEW TTS?
thought are appreciated.
ALSO..i have an old thermostatic actuator from a 1750 spica for sale/make offer.
thanks to all.
The ECU is not in the circuit. Unplug the connector to the CSI and with the ignition on you should get 12 volts on one of the connector pins. The injector opens when the other pin is pulled to ground by the TTS.
The ECU is not in the circuit. Unplug the connector to the CSI and with the ignition on you should get 12 volts on one of the connector pins. The injector opens when the other pin is pulled to ground by the TTS.
thank you.
 
#14 ·
OK, that is something...means the TTS is getting power (which is there to heat the bi-metallic strip and that should make the ground circuit to the CSI), which means "this" grey/green at connector G121 behind the glovebox is ok (that was one of my worries)

Now, do you also get 12v whilst cranking on the grey/green of the CSI? (this also runs through G121)
(Both need to receive power whilst cranking...the TTS then completes the ground - as long as it is cold enough outside - and the CSI fires)

and finally is there continuity between the blue wire of the TTS connector and the blue wire of the CSI connector
 
#16 ·
When these fuel injection systems are working right they are wonderful. I've had my '85 Graduate for about 7 months. The guy who sold it to me told me, "When you start it don't touch the throttle!" As long as I keep my foot off the gas it always starts instantly, no matter what the temperature, even after sitting for a week or two.
 
#19 ·
Get one of these. It makes testing very easy.

You plug it into the TTS connector it should light up when you crank on the car. If it doesn't light up you have a problem in the wiring to the TTS. If it lights up connect it to the CSI if it lights up the TTS works. If not its bad.

Remember the engine has to be completely cold. Once it runs for a minute the coolant will be to warm.

There are probably cheaper ones. This was the first one that popped up. Bosch uses the flat blades. Like the picture shows.

 
#22 ·
thanks.
another member mentioned similar.
I have 3 used TTS' total, each one testing progressively different. makes me trust my testing method.
Originally all was fine, started and ran. then no start. found no spark. Crank sensor faulty, replaced. now have nice spark, but just sputters momentarily
CSI sprays great straight wired.
Current at TTS w/ IGNITION ON, AND cranking. blue wire from TTS to CSI is good.
Having current w/ignition on, is that letting the thermal preheat and then turn off as it should essentially?
Should I have current at TTS w/just ignition on?
sure appreciate your thinking it w/ me.
 
#24 ·
that's exactly what i'm led to think.
i've had to work under the dash quite a bit, but NOT since it was running
that being said when it was starting ok, it was outside in warmer weather.
perhaps the TTS wasn't working way back then.
the relays, main and running all are fine.
the g121 connector seems tight although very hard to get to it.(car has a/c ductwork).
thanks for your help previously, by the way, 'spiderserie4'
 
#25 ·
that being said when it was starting ok, it was outside in warmer weather.
can you just confirm that you are only experiencing a cold start problem?
in other words you car starts easy and runs well when it is warm?

I would have thought, even if the TTS was powered with KO (instead of, as it should imo, only whilst cranking) then the CSI should spray....

one thought (as silly as it seems;)) comes to mind - you are absolute certain you have the correct brown connector on the TTS, and it hasn't been mixed up and stuck on one of the other sensors close by?
 
#26 ·
car's in a garage 60 degrees. it doesn't even fire momentarily at this point.
DID discover violet middle connector on TPS bad. have sent for a replacement pigtail, due on Wed.
'pin checking' ohms so far on fuel ECU is fine.
when it was firing briefly, it acted as if it had air leak and would stop.
can't thank you enough for the attentions.
 
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