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914World.com _ 914World Garage _ 1973 1.7 D-jet

Posted by: Hammer920 Apr 27 2004, 10:03 AM

I am a new member and have been working on this over 1 yr. This is what i have replaced so far, new points and plugs, put back on vac advance on distributor new fuel pump and filter all new fuel lines and vacume lines no leaks, #2 sensor by # 3 cylender, new oil sensor by distributor. timed at 3500 rpm white mark is +5 degrees off cold or hot.
When the engine is cold will run fine after 30 min driveing when you stop for any reason it dies have to give it a little gas to start back up. with new oil sensor oil light lites up at 1200 rpm then goes away ay higher rpm oil is full.
04/25/04 can adjust the mixture at the throttle valve but the ecu wuold not adjust took the ecu apart the pointometer adjuster was broke inside Will replace the ecu it does smell like burnt electrical.
the only thing injection wise that has not been replaced is the trigger points, ECU, pressure regulator and the Pnuematic decelleration valve, you can remove the vac hose on the dec valve when warm and the car will stay running.

Any Suggestions

Posted by: mike_the_man Apr 27 2004, 10:55 AM

You can get rid of the decel valve. It's just for emissions. Give that a try and see if it helps. Have you tested the Manifold Pressure Sensor (MPS)? Could be that it's not holding a vaccuum, so the car would be running really rich. What does the car idle at when cold? Should idle high (around 1800rpm, I think) when cold, then as the car warms up the idle should decrese to about 900rpm. It could be that your cold idle is set too low. Also if you haven't seen this page before, check it out.

http://members.rennlist.com/pbanders/

Posted by: Demick Apr 27 2004, 11:17 AM

Off hand, it simply seems like your idle speed is adjusted too low. When the car is cold, the aux air regulartor compensates for this, but once the AAR closes, your idle speed drops too low and the car dies at idle. Your AAR heating element is probably not working as well because it should be closed within about 5 minutes. If it takes much longer than that, then the heating element is not working (or it is not connected to a power source). The AAR will still close, but it takes much longer because it muct heat up by conduction from the engine itself.

By disconnecting the vacuum hose to the decel valve, you are really just creating a big vacuum leak, which is the same as opening the throttle, which is the same as opening the idle speed bleed screw). That's what makes me think that you just need to adjust the idle speed to be higher when the car is warmed up.

The broken pot in the ECU might also be somewhat to blame since that adjustment controls the mixture at idle. I would replace that.

Demick

Posted by: 415PB Apr 27 2004, 12:17 PM

Glad you finally joined Hammer920. I got your email reference the ECU numbers. I will check it tonight.

Posted by: Hammer920 Apr 29 2004, 08:50 AM

The car when warmming up Idles at 1800-2000 rpm for about 15-20 min does sptter a little very little when warming up and exahust does smell a little rich. Looked in the Haynes book for the mps it shows one for the 1.7 L-jet but nothing for the D-jet. after 15-20 min it Idles down to 900 rpm runs smooth. I have tried to raise the idle speed after warming up to 1200 rpm not the right Idle speed still afrer warming up and driving for about 5 miles does the same thing or just sitting idle for 30-40 min. I took off the AAR connected to power supply (Battery) it did warm up and close with in 5-min will check the wireing connection to it. I am going to replace the ECU, Trigger points, and the pressure regulator
Thanks For your Help and replies.

Posted by: Dave_Darling Apr 29 2004, 10:42 AM

All 1.7s were D-jet, L-jet was only the US-spec 1.8s. L-jet also has no MPS, it uses an Air Flow Meter to measure engine load instead.

Clean up the grounds at the back of the engine. Can't think of anything else right now offhand.

--DD