Finally got Voltage to the Cold Start Inj but after one second the V drops to 10V and it wonbt open Ideas

2668 Views 14 Replies 0 Participants Last post by Brian Stewart, Mar 3, 2004

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Discussion Starter · Feb 22, 2004

Ok guys. I finally got my CSI

Ok guys. I finally got my CSI and TTS Voltage as they didn't have any before. Now I have 14V for the first second when turning the engine over but it drops to 10V right after and stays there while the starter is turning or while the key is in the III position. What could be causing this drop? Dirty connection at the starter? It also happens at the Cold Start Injector Fuse inside the car so it must be up stream. Is the CSI suppose to open only at 12V or should 10V be enough to open it? Thanks.

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G

Discussion Starter · #2 · Feb 22, 2004

Rich,

The CSI is only suppo

Rich,

The CSI is only supposed to spray for the 1-3 seconds while starter is turning then shut off, just as the fuel pump does, to prevent flooding in the case of a no start.

sounds like it's working properly now.

G

Discussion Starter · #3 · Feb 22, 2004

Rich,

the CSI sprays the mi

Rich,

the CSI sprays the mist into the Intake Housing simply to create a very rich primer shot of A/F mix...then the lower pressure of the WUR takes over after the engine is running.

G

Discussion Starter · #4 · Feb 22, 2004

I know but I tested it when co

I know but I tested it when cold and it didn't spray again but got 14V for a 1/2 second or maybe one second then dropped to 10V and it didn't spray.

Is it normal to see a drop to 10V during normal cranking?

G

Discussion Starter · #5 · Feb 22, 2004

>>Is it normal to see

>>Is it normal to see a drop to 10V during normal cranking? <<

I've never checked that....but it sounds possible if the starter is drawing current away from the circuit.

The FP relay will shut the pump down after 3-5 seconds no matter how long the starter is cranked, so I would suspect the voltage reading/feedback you are getting is why the diode replaced the fuse.

G

Discussion Starter · #6 · Feb 22, 2004

Maybe but I have the diode in

Maybe but I have the diode in place now. So it should be ok. It should be spraying but for some reason it isn't. I checked cont. from the G wire to the TTS and it is grounded and the white wire has the 14V-10V start up. It should spray. When I put 12V to the CSI by itself it atomized perfectly. A very nice mist. Oh well I will keep you posted. Thanks.

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Discussion Starter · #7 · Feb 22, 2004

Rich,

check the ground &amp

Rich,

check the ground & the hot at the CSI and see what you get. Maybe the ground circut is bad?

then maybe try with a fuse instead of a diode?

also, I'm not sure where or how you are getting 14v's, instead of 12v's ?

G

Discussion Starter · #8 · Feb 22, 2004

Beats me. Ok I got it to WORK

Beats me. Ok I got it to WORK!!!!!!!!!!!! YAAAAAA!!!!! I feel good. I checked continuity between the ground for the CSI that the TTS feeds it. It was fine by my Multi-Meter, showed a closed circuit and I could ground it in various parts of the engine and it was still closed and it would beep. I thought well, I will make a ground and put it in the rear of the harness for the CSI and then connect it back up and see if it sprays. I turned the key and it Sprayed just like it was suppose to.
Now I am not sure if the where the problem is in the ground (green wire from the TTS to the CSI). Maybe in the TTS however all resist. values check out from specs in the WSM or maybe somewhere in the wire. What is strange is that my Multi-meter shows continuity between the wires and no break.
I am very very excited. Persistance definitely paid off. I appreciate everyones help on this matter.
JRV you are 100% correct some part of the ground isn't correct in the circuit. Not sure about the 14Vs but that is what I get when first cranking. Then it drops. Once the engine fires and is running it levels off to 13.34V.
Now to just fine out where the bad connection is or if it is in the TTS. Thanks Again.

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G

Discussion Starter · #9 · Feb 22, 2004

WHHHOOOOOOOOO HHOOOOOOOOO!!!

WHHHOOOOOOOOO HHOOOOOOOOO!!!

Congrats man !!!

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G

Discussion Starter · #10 · Feb 23, 2004

Remember that the ground is ma

Remember that the ground is made via the threads of the thermo time switch, sometimes loosening and retightening will produce a stronger grounding. If not just replace the switch, it is inexpensive.
The secret to electrics? understand the system and how it works, then check the ground, then the power track. Nearly always the basics turn out to be at fault, when everything is checked then go through 1) sensors 2) wiring continuity 3) control unit.

glad you are getting there, it is good training!

brian

G

Discussion Starter · #11 · Feb 23, 2004

Brian I know what you are sayi

Brian I know what you are saying but it wasn't like that in this case. Maybe you can tell me what I did wrong when I tested it but I think I did everything correct. I removed it and cleaned it. I checked resistance values from W & G and W/housing and G/housing at the correct temp and compared with the QV WSM. All are in spec. I took the test a step further and put it in cold water, checked for continuity between W&G and got it. Then put it in warm water and the didn't get continuity between W & G. This is what I expected. The switch opens warm. Put it back in checked for 12V at CSI and TTS. Got it but still no spray. Checked for continuity between the CSI & TTS which is the green wire from the CSI to the TTS. Wire is fine. Then checked the green wire (ground wire) at the CSI harness to the engine block and guess what the Multi Meter beeped indicating the ground was good. I then tested W to engine, beep it was a good connection. I even went to the BMW manual and put a Test light on the Battery + to the W on the TTS and it lit right up as it should. I even made a seperate ground around the TTS to engine and no spray.
I installed another TTS and guess what the CSI sprayed. Every test I did showed that it was functioning properly but apparently it wasn't.
What baffles me is why all of these tests showed that the TTS was working when it clearly wasn't working properly. As soon as I switched them it sprayed. (this is after repairing the bad diode in the Jetronic area) However, all of my tests were performed before and after the diode repair.
Anyway, if you have some tips or the like please send them as I did everything by the book from the way I see it and the TTS shows that it works. I put it in another CIS car and the CSI doesn't spray yet all of the test show it works.
Long Story but I am thrilled it is working.

35 deg. weather F this morning. Turned the key and my 85' 308 QV lit almost instantly. It was a beautiful site. Smooth as glass during the warm up too. Thanks Again Guys and keep me posted Brian.

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G

Discussion Starter · #12 · Feb 23, 2004

Hi Richelson,

Do you have

Hi Richelson,

Do you have the Bosch part # of the proper TTS? Is it stamped 15c or 35c or something to that effect?

Your story is true mechanic work. Although cannot figure why would test properly.

Carl

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G

Discussion Starter · #13 · Feb 24, 2004

The Bosch test procedure simpl

The Bosch test procedure simply states that IF 12v is present when cranking at the connector for CSI but a test lamp does not light for a few seconds, replace the thermo time switch, it does not ask for any continuity test, just replace. Interesting, huh?

G

Discussion Starter · #14 · Mar 2, 2004

Please don't think I'm

Please don't think I'm stupid, but I have a question.

Why do Ferrari's have such a unique sound when starting up? Is a special started motor or does the size of the engine make a difference?

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G

Discussion Starter · #15 · Mar 3, 2004

The "flat crank" layou

The "flat crank" layout in the Ferrari 8 cars seem to contribute, the sound is similar on my cosworth DFV. Also the gearing may give a higher crank speed. just my observation.

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