Very disappointed, am I loosing time on my car? Options

[VINCE]

I feel very bad tonight. I bought my first 914 one month ago. I am working on it every evening since one month and sometimes until midnight (it is very cold in my garage)... (IMG:style_emoticons/default/sad.gif)

I think I am loosing time. The more I do, the worst it is. The L-jetronic make me crazy (the 914 is a stock 1.8L from 75).
For example, the engine was runnig two days ago (only on idle because if I tried to open throttle the engine was dying): my cold start valve was OK. And tonight, the cold start valve is not working anymore!!! What is wrong? I don't understand.
It seems I have fuel pressure because when I disconnect the fuel pressure regulator I see a fuel spray. I don't understand how this cold start valve is working. Wich sensor is related to the cold start valve?
It is the same thing for the 4 other injectors... I have no fuel spray.

I have tested (according the Haynes diagnostic method) the air intake sensor
and the throttle body and they are OK.
The only thing I am dubious is the temperature sensor II. Where is it? How I disconect it?

I really need to fix it quickly because it is my daily driver. Should I carb? With what carbs? I need the car run in winter but I don't need more hp. Is it possible to find and adapt 40 PDSI? Can I find manifold and throttle linkage for 40PDSI quickly?
Should I try to continue fix my L-Jetronic?
Should I buy an other car?

Please, help me. I am sure some of you have been in the same situation.

Thanks

Vince

[bd1308]

Dont focus on the small little things--step back annd look at the big picture.

Nothing works without power to the ECU, just as a tip from someone Daily driving a L-jet injected 914, I'd focus on the electrical side of things. You have fuel, which is good

check, recheck, and when you think you have it done, check it again.

start at the dual relay. That was the source of 90% of my problems, even the fuel pump would intermittently cut out when driving when my dual relay died.

I'm a big proponent of FI, but i consider myself to be computer savy.

not having the cold start valve leads me to believe your l-jet computer is not getting power.

Well, never mind. It seems that the fuel pump is running, and that would mean the ecu is on.

Let me think more on this issue.

[jd74914]

Check the grounds. Most electrical problems revolve around messed up grounds.

[Dave_Darling]

The cold start valve (CSV) dumps raw fuel into the manifold. It does so only when two things are true at the same time: 1--the starter is cranking; 2--the thermo-time sensor (TTS) is "cold enough" (probably below about 40 degrees F). The TTS is, as I recall, located below the CSV on the L-jet cars. It may be on a bracket sticking out from the manifold (as on the 2.0 D-jet cars) or it might be tucked partly under the manifold, I don't really recall.

The CSV should not have any effect unless your engine is really very cold indeed.

No signal at all to the fuel injectors sounds like an electrical problem. Check the white wire that plugs into the (-) terminal on the coil. That tells the EFI when to open the injectors. (That is in addition to what the others are telling you, above.)

--DD

[eeyore]

Go to http://www.ratwell.com

Especially limping home with L-jet

Depending on how cold it is in MI, you may(?) be right on the threshold of when or not the CSV activates.

Obvious things: Make sure the fuel lines are plumbed the right direction. Get new fuel filter.

[VINCE]

Thank you very much for your advice.
I feel more confortable with the L-Jetrconic now.

This evening, I will check my electrical connections of the double relay (from L-jetronics wiring harness & vehicule wiring harness)
I will also try to check the temperature sensor II: if I unplug the TS2 will the cold start valve continue to leak?

I will give you news of my work.

Thanks

Vince

[VaccaRabite]

Hi Vince,

Hope you get everyhting fixed up. I know what you mean about feeling like you are loosing time when working on one of these things.

If you are using your 914 as an only car, I might suggest picking up some sort of cheap beater, like an old honda civic or something like that. Somehting that won't cause you heartache as your winters kill it, and that will start up most mornings without any hassle.

Zach

[double-a]

i had some of the same problems with my 1.8, and i found a lot of good info here:

http://manuals.type4.org/ljet

~a

[VINCE]

One more a night in my garage for nothing...
I have tested the wiring harness according the website link you gave me: everyting seems to be working... exept for the resistance between ECU plug terminal 20 and system ground at terminal 17 with ignition ON: I have 647 ohms (Test Chart says 52-78 ohms). Does that means that my fuel pump relay is defective? I don't think so because I can activate fuel pump by pressing the AFM flap witouht any problem.
Underlined wires on the enclosed FI wiring harness diagram are OK: I have tested all of them yesterday evening. I have 2-3 ohm for each injector. 4 ohm for cold start valve injector.

Is it possible that the ECU is defective? How can I test it?
When I start the engine I have no spray at the cold start valve even if the wiring connections seem to be OK. Can I put 12V and ground to my cold start valve to see if it is working?

The engine was runnig sunday evening, so I don't think I have an ignition problem.
Fuel pressure seems to be good because I have a spray when I disconnect a fuel hose.

Thank you for your help.

Vince

[Mid_Engine_914]

When I start the engine I have no spray at the cold start valve even if the wiring connections seem to be OK. Can I put 12V and ground to my cold start valve to see if it is working?

Vince

Did you test the resistance in the cold start valve's windings? You should measure about 4 ohms between terminals 45 and 46 in your pic.

You should also have continuity between terminal 45 and thermo-time terminal G (see figs. 6 and 7 in your pic) and terminal 46 and thermo-time terminal W.

[Mid_Engine_914]

Also test the resistance of your thermo-time switch between terminal W and ground. You should get 0 ohms below about 60 F and inf somewhere above 60F.

[Rusty]

I don't have any technical advice for you, as I'm not an L-Jet guru.

However, back when I owned a 74 1.8, I learned that the L-Jet system is very sensitive to vacuum leaks. So much as having a bad gasket on the oil filler cap will cause the engine not to run.

Good luck and hang in there!

-Rusty (IMG:style_emoticons/default/smoke.gif)