Hot and Cold idle miss on my D Jet

[Graham]

Originally Posted by meltedpanda

lol, hear ya, I went "shopping". ANyways back at it and realized several of my connectors to the "senders" temp 1 temp 2 and even the trigger points are in bad repair, anyone find a source for these or an aftermarket connector that would work. I thought these buggers came apart but they dont!

You can buy a whole new harness that includes all the connectors - Lists at ONLY about $850 but maybe $600 from some sellers.

I obtained part of an old harness that had some good connectors so use those as spares and for testing - I think the sensor ones are same as injectors. Have you tried Mb Classic Centre to see if they sell individual connectors?

BTW - To check if the connectors are the problem, you could check the circuits back at the ECU connector plug using the method in the manual. One of those Bosch D-Jet testers would make that a lot easier, but where do we beg borrow or steal one of those?

[Gurunutkins]

It depends on if you want to stay original or not - as always I am quite happy to modify mine but I know you show yours.

you can replace the injector and temp sensor (air and injector water temp) with these bosch connectors - they are just over $1 each but you have to buy 10 minimum.

http://www.delcity.net/cartviewitem?item=73522&search=y

you do have to cut out a small tab with your dremel tool so they look like this


here they are on the air temp



for the connector on the trigger points i had to just replace one side of the connector with colour coded bullet connectors.

hope thats some help
cheers
Barri

[meltedpanda]

OK TPS cleaned and adjusted to zero ohms at idle, it was off and may help. Onto the ECU for singnal checks manual says to check pin 3 4 5 6 for one test, I look at my plug and I have 5 - some bad repair in past or this is OK, I have not known MB to put a 6 prong plug and use 5
number 6 in missing ????
Why did I start this.....

[meltedpanda]

OK then, I need to to read more, I am not looking at the right harness am I . it talks about harness pins up to 20 or so, where the heck are these on this ECU, I only see this plug , no others??

[Graham]

Originally Posted by meltedpanda

OK then, I need to to read more, I am not looking at the right harness am I . it talks about harness pins up to 20 or so, where the heck are these on this ECU, I only see this plug , no others??

Ron,

If you unclip the ECU, you will see a wide connector that connects the main harness to the ECU. Disconnect that plug, then go through the series of tests as outlined in the manual.

PS: If the TPS was not set properly and was not signalling to the ECU that you were at idle, that could be part of your problem.

[meltedpanda]

OK bag the ECU to the connector tests, too much work. Looks like I have to take it apart to get to the pins. I see no large connector , just that small one

todays wrench :
-Took intake off -TPS dismantled and calibrated, cleaned. While I was at it cleaned intake of gummy depsosits and such. Now reads 0 ohms at closed.
Ohm tested temp sensor 1 and 2 - perfect
Ohm tested MPS - coil 1 and 2 - Good
Reset points to .011 dwell was reading a little low at .012\
Cleaned off fly wheel so I could see timing marks, in anticipation of timing this week

TO DO
pressure test fuel pressurer at fuel rails
timing
try and figure out how to fix the connector on the trigger points. Original is what I would like to keep
fix a few bad connectors/wire cracks

FIND A CO Meter!!!

Fire her up....

[Gurunutkins]

Hi Ron
the ecu just clips in the bulkhead behind the glovebox, one clip and then pull the top out and it will pop out. the connector is a grey plastic strip down the open end just undo the 2 phillips screws holding the harness and it pulls off. the ecu side looks like this but you want to test the plug side (dont have a pic) although some of the tests you backprobe the plug with the ignition on.

once you get the ecu out its pretty easy to work on
cheers
barri

[Graham]

Originally Posted by meltedpanda

OK bag the ECU to the connector tests, too much work. Looks like I have to take it apart to get to the pins. I see no large connector , just that small one

todays wrench :
-Took intake off -TPS dismantled and calibrated, cleaned. While I was at it cleaned intake of gummy depsosits and such. Now reads 0 ohms at closed.
Ohm tested temp sensor 1 and 2 - perfect
Ohm tested MPS - coil 1 and 2 - Good
Reset points to .011 dwell was reading a little low at .012\
Cleaned off fly wheel so I could see timing marks, in anticipation of timing this week

TO DO
pressure test fuel pressurer at fuel rails
timing
try and figure out how to fix the connector on the trigger points. Original is what I would like to keep
fix a few bad connectors/wire cracks

FIND A CO Meter!!!

Fire her up....

Ron - As barri said, ECU connector is relatively easy to get at and test - You have to remove the covering inside the footwell held on with plastic rivets - if it is still there! Then you can see the ECU. It is held in by one spring clip. Unclip then pull on unit and it will come out. As barri said, a couple of phillips screws and you have it. I don't recall there being any plug like the one you posted. You are looking at the ECU? Picture below.



The trigger points of course signal when the ECU should fire the injectors. If the connector is bad or the trigger point fibre followers are worn, this can severely affect engine performance.

[meltedpanda]

Barri, Ghraham, thanks again
I think the 5 prong plug I was looking at is just in as a follower and not tied into the ECU. I swear I did not see any a way, on that side, to access ECU pins, but will look again. Mine looks exactly like the one shown. I would like to test the injector wire readinings through the ECU. The others as well.

Fuel pressure guage set up is next , boy those things are expensive , and would like to fabricate one somehow, anyone do that and can suggest an alternative method??

Anyone have an extra trigger point connector???

seems like I saw a few 107s being parted out , I'll ask!

[Graham]

Originally Posted by meltedpanda

Fuel pressure guage set up is next , boy those things are expensive , and would like to fabricate one somehow, anyone do that and can suggest an alternative method??

I currently have a permanent fuel pressure gauge with electric sender and dash gauge. Initially, I took the clock out and mounted the gauge there, but now have a separate panel for the fuel pressure and AFR gauges where the ashtray used to be.

But prior to this, I checked fuel pressure with a simple setup. Just installed a 5/16" tee in fuel rail hose and a simple water pump pressure gauge that you can buy at any hardware store. It would be best to find a 0-50psi gauge, but most of them are 0-100 and not so easy to read small differences. Any oil or water gauge should do for a temporary setup. Try Summit for the gauge. I "borrowed" this pic from another site.

[meltedpanda]

thanks , that helps, I will build my own. Place it between the CSV the fuel rail , correct?

I am still in amazement that there are no aftermarket connectors that will work on these old injectors and varrious senders ( and not have to take out a loan ) . I may just go with what Barri has shown , I gotta do something , still wont solve the trigger point connector. I posted in wanted. I am also going to call MB classic

[rowdie]

I shall look at the '72.
Nope it is broken.

[Graham]

Originally Posted by meltedpanda

thanks , that helps, I will build my own. Place it between the CSV the fuel rail , correct?

That is one place, but the hose is kind of short. I put my permanent pressure sensor in the hose that crosses over the front of the engine (see pic). It could also go at the back in one of the hoses. There is little pressure loss from front to back of engine, so any convenient spot will do.

By the way, there is another thread on this subject.

[meltedpanda]

thank you for the picture, the manual gives the spark gap .028-.032 what do you find as the best gap . I figure I need to do all of this since I am into it . I pulled a plug and it shows signs of running rich. And so the transducer runs to a guage in the car??

[Graham]

Originally Posted by meltedpanda

thank you for the picture, the manual gives the spark gap .028-.032 what do you find as the best gap . I figure I need to do all of this since I am into it . I pulled a plug and it shows signs of running rich. And so the transducer runs to a guage in the car??

I think 0.030 is correct - Both NGK and Bosch plugs come preset to the correct gap, so I am not 100% sure. The points (if you don't have a pertronix) are preset to 0.014 (and then later dwell is checked).

Yes - I have a gauge in the car: See this link. Other gauge is wideband AFR which does the job of a CO analyzer. Don't really use the pressure gauge except once in a while to check for leak down.