2.0 FI Problems

[RonD922]

Hello,

I just acquired a 74 2.0 FI and I was wondering if you guys had any ideas as to my car's behavior!!

First-Only ran on one cyl.-Pulled injectors and soaked them then they worked again..

Second-I had a horribel gas leak and now I have replcaed all the hoses so I am getting fuel to the injectors and no leaks!

The car started fine and ran on all cyl. but Idled at 2200 RPMS..I finally found the vacuum leak and have reconnected the hose..So I now have an idle speed somewhere in the neighborhood of 5-800 RPMS.

1. The problem is that it backfires and misfires when idling...

2. I have no power!!It will not rev over 4000 RPMS when under load-moving...

3. Has a mean hesitation so that when I depress the gas it balks and gasps then revs up to 4000..but no higher!!

I am going to check the fuel pressure and volume tommorow, maybe the timing also...But I was wondering if these symptoms sound famailiar to anyone and they would like to share a solution or it least something to test or Try!!

Thanks For All The Help,
Ron

[Bleyseng]

Check the timing and the condition of the distributor. Rebuild if necessary or replace. Check the FI points while you are at it.
Check the valve adjustment too, hell may as well goes though the whole car to see what the PO screwed up............and you are going to have to find it and fix it.
Geoff

[Dave at Pelican Parts]

Step 1: Check the ignition--thoroughly. Check the condition of the ignition bits, check the adjustments (timing and dwell), etc.
Step 2: Check the vacuum hoses. Brittle or cracked ones should be replaced. Check for leaks using your favorite method (e.g., squirting carb cleaner, etc.). Check for unplugged wires.
Step 3: Check your valve adjustment, and your compression.
Step 4: Check that the FI parts you have are the correct part numbers for your application. (See later for a reference of which ones go with what.)
Step 5: Start checking individual FI parts for correct function.

Your symptoms sound something like really cruddy ignition points, and also something like a really rich mixture. You might try the "suck on the MPS" test to see if it holds a vacuum at all (use new hose, some of the stuff inside the manifold is really nasty or even toxic). The head temp sensor is another popular cause of an overly-rich mixture.

Sources for info:
Good concise readable article: http://www.914fan.net/djet.html
Source for part numbers and just about all the info that is known about D-jet EFI: http://members.rennlist.com/pbanders

--DD

[Bruce Allert]

I replaced all hoses (and added hose clamps) and then found the ECU to be dialed to the full open rich position. (wouldn't turn clockwise any more). Kept turning it until it sounded good, drove it, turned it some more (one click at a time). That seemed to solve most of my problems.
bruce

[3D914]

Ron,

There are two main FI components you can check right off that will affect you in the way you're describing:
1) Head Temp Sensor (lead sticking out of tin next to #3 cylinder).
Check its resistance when hot. It should be less than 100 ohms. I just replaced one that read 200 with similar symptoms. Also check it cold. It should be approx 1500 ohms, not too much higher. For a 74, you should be using the 0 280 130 012 (bosch) sensor regardless of what the parts store says.

2) Manifold Pressure Sensor (down & left of battery)
Use a hand-held vacuum pump. Disconnect the hose and with the pump hose attached, you should be able to pull a vacuum to 20in-hg and it should hold without dropping. If it drops 5 in-hg within a minute, the diaphram is bad. There are other test as well that you can get from Brads FI page. Dave provided a link in his reply.

Aside from obvious ignition/timing problems, these are a couple of useful checks.

Enjoy,