D-Jet sputtering Options

[JtoTheBeezy]

With no consistency my 2.0 fi car will sputter and shutter. Its hard to tell weather its a lack of fuel or a lack of spark. Its fairly speratic but constant once the car is warm. What I usually have to do is stomp it or feather it past 4k rpm and it runs fine above 4k.

Things ive fixed/replaced
New oil and filter
new fuel filter
Checked/replaced any bad vacuume hoses
replaced and calibrated the tps
checked mps
checked aar. Stays closed 24/7 which is better than open randomly
new cap
new rotor
Adjusted timing to the best of my ability (IMG:style_emoticons/default/blink.gif)

I've owned this car for over a month now and it has never run properly due to this problem. Today im going to check the injector points and do a valve adjustment. I can hear the injectors firing with the key in the on position but they could still have issues I suppose. Help me... carbs are calling my name. (IMG:style_emoticons/default/bs.gif) (IMG:style_emoticons/default/WTF.gif)

[r_towle]

Adjusted timing to the best of my ability (IMG:style_emoticons/default/blink.gif)

Really?

Sears sells both timing lights and dwell meters.
You need one of each to tune up a 914.

It is THE most important thing you can set and adjust on the car, maybe more important than the valve adjustment IMHO...

I can burn up the motor if down by ear, it can do damage.


Get some tools and welcome to the fun.

[JtoTheBeezy]

Adjusted timing to the best of my ability (IMG:style_emoticons/default/blink.gif)

Really?

Sears sells both timing lights and dwell meters.
You need one of each to tune up a 914.

It is THE most important thing you can set and adjust on the car, maybe more important than the valve adjustment IMHO...

I can burn up the motor if down by ear, it can do damage.


Get some tools and welcome to the fun.

I definitely have a timing light. Timing marks is what im missing. When I Time it to the mark I see it runs like crap. I had it at 3500rpm when I did it. Advanced it a little bit more than the mark.

Ive also realized that it is for sure backfiring so for some reason my car is refusing to burn the fuel. How do I check a cht?

[BeatNavy]

How do I check a cht?

I would focus on dwell and timing as suggested, but if that doesn't help then checking the CHT may be worth it:

Cylinder Head Temperature sensor is located near #3 cylinder. You'll see a sensor wire coming out of the engine tin connecting into a wire off the FI wiring harness. When the engine (and CHT) are cold the circuit resistance between ground and the CHT will be high (~2.5K Ohms depending on year) which ECU uses to enrich the fuel mixture by leaving injectors open longer. As engine warms up, the resistance in that circuit drops down closer to 100 ohms, and the ECU leans out the mixture. A proper functioning CHT (and CHT circuit) is extremely important. You check it by disconnecting the sensor from the wiring harness and checking the resistance value (with an ohmmeter) between sensor lead and ground (negative battery terminal). Do this with engine both cold and fully warm.

If you haven't already, check out Paul Anders' site: D-Jetronic Parts Analysis and Troubleshooting which has TONS of good info.

This is some of the info on the CHT from his site:

•Function: Senses engine temperature and sends signal to the ECU to provide mixture compensation. Proper part for your application and proper functioning is extremely important!
•Normal Value(s): ◦0 280 130 003 and 0 280 130 012: about 2.5 K ohms at 68 deg. F, less than 100 ohms with hot engine.
◦0 280 130 017: about 1.3 K ohms at 68 deg. F, less than 100 ohms with hot engine.
◦See Notes section below for more data on the resistance vs. temperature values of these sensors.

•Failure Modes
◦Open: The ECU interprets an open sensor as a signal to greatly richen (e.g. I've measured an over 3X effect) the mixture. This usually makes the car impossible to start and causes it to stall if the sensor fails open while running. Check by disconnecting the sensor from the wiring harness and measuring the resistance to ground, refer to the values above.
◦Shorted: The ECU interprets a shorted sensor as a signal to lean out the mixture (about 30% leaner). The car may run and start in this condition, but will have poor idle and drivability. Check by disconnecting the sensor from the wiring harness and checking the resistance to ground. Note that shorts are often intermittent, caused by nicks in the sensor wire and by exposed contacts to the wiring harness touching ground. Check by inspection.