One cylinder poppin', Help me D-Jet gods!! Options

[BiG bOgGs]

I pulled my 76 2.0 stock fuel injection engine a few months back so that I could plug up some oil leaks. Other than the leaks, the engine was running O.K. Well, as O.K. as I could tell after a couple of weeks of owning my first 914. I put the engine back in just a couple weekends ago and have slowly been trying to get her going again. For a couple of days I could only get her to spin with the starter, but I wasn't getting any fuel.....I figured out today that I hadn't connected the wiring harness to the distributor. Now that I have it connected I cranked her over and I am now firing on just the #3 cylinder. I also don't smell and raw fuel coming out of the exhaust. And when I open the throttle, she seems to power up a little bit, but not much.


major points

76 2.0L D-Jet

rebuilt/cleaned injectors from cruzin performance

new large and small injector rubber

new vacc. hoses all around

just had it tuned up before I needed to pull the engine and I didn't screw with the ignition system at all.

I hear no clicking when I move the throttle switch (thought I was supposed to hear the injectors clicking)


If there are any other bits of info that will help in the trouble shooting process please let me know.

Jim (n00b)

[Dr Evil]

Jim,
Make sure there are no broken ground wires for the injectors at the junction block. The injectors fire in pairs so to have one not firing and no fuel smell probably means that you are either not getting volts, or it is clogged. You can put a noid light in the plug for the non-firing injector to see if it is volts.

[Dr Evil]

Ah, a re-read your post and now see you are firing on ONLY the #3. You need to think about what they all have in common. You connected the trigger points in the dizzy and that would cause all of them not to work, as you discovered. The fact that you can have it running at all means that you have more than #3 firing, but I would start with the ground block on the engine under the air plenum.

What makes you think that #3 is the only one firing? Check the volts to all the injectors. Since they were cleaned the most likely cause is bad grounds.

[BiG bOgGs]

I have it running on just #3 because I disconnected each spark plug from the dizy one at a time and the popping of the engine didn't change until I unplugged the wire going to the #3 cylinder... the engine died. Plus, I feel pressure coming out of both sides of the engine, but the popping coming out of the passenger side is warmer and more powerful.

[Dr Evil]

Are you sure that the others are receiving adequate spark?

[BiG bOgGs]

Fairly sure they are getting good spark. Will check again. I don't smell any raw fuel coming from the exhaust, so I am wondering about the injection.

If both sides of the FI fire together, can I swap the injector harness between the passenger side injectors and see if I get the other cylinder to fires?

[Dr Evil]

The injector fire diagonally. I forget the numbering of /4 cylinders, but it is something like 1-3, 2-4. You can try swapping the plug to the next closest injector for a simple test.

The fact that you are not hearing the clicking noises when you throttle tells me that your injectors are not hooked up correctly, though. The clicks you should hear are the injectors all twitching with more throttle via the TPS.

Did you check the grounds? The white wires that attach to the junction that I described earlier?

[BiG bOgGs]

At the rear of my harness, just to the passenger side just behind the intake, I have 6 white wire exiting the harness. the PO had them all spliced into a wire leading to the negative terminal of the battery. I cut his wire and re spliced it to see if his handy work had been loosened in the process of removing and re-installing the engine. Same cylinder runnin. No Change.

[BiG bOgGs]

Should I ground these 6 wires to the engine instead of the negative terminal?

[BiG bOgGs]

Dr, thanks for your help thus far. I now have to go help my Dad do some moving of stuff into storage. Please keep the suggestions coming and I will check them all out when I return in a couple hours.

[Dr Evil]

Ding ding ding! Yup, those are supposed to be ground to one of the screws on the engine case top. 4 of those 6 are the grounds for the injectors, I am not sure about the other 2, but they all should be grounded to the block to start with. They originally had spade connectors on them and there would be a junction for them under one of the case through top screws.

This may not solve your problem all together, but it is a start.

[Dr Evil]

Right on, if I think of anything else I'll post it. I am going to go study neurology now (IMG:style_emoticons/default/wacko.gif)

[BiG bOgGs]

Otay! I got the 6 wires connected to the male connector on the top of the engine just below the #3 intake runner. I also checked the injector wires be pulling each in turn and testing them with the engine cranking. I get voltage movement with each of them, but the front driver side wires were fluctuating at a higher voltage than the others. And still, even though I am just running on the #3 cylinder she is running stronger now that I have grounded the wires on the case.


Just thinking, #3 is the first cylinder to get fuel. If my pressuer is just low enough, would the firing of the #3 cylinder be enough of a pressure drop to give too low of a fuel pressure for the rest of the injectors?

[Dr Evil]

That question made my head hurt (IMG:style_emoticons/default/rolleyes.gif) Nope. You should be firing 2 at a time. You may need to check and clean your FI points connector at the dizzy to make sure you are getting good contact to all of your injectors. Check your fuel pressure. If this is off the rest of your efforts will be in vane (vein?).

Since your injector leads are getting voltage, you can easily test to see if your injectors are actually spritzing fuel. A 10mm socket will free the injectors and then just spray them into a cup. No spray + yes power = injector bad or fuel pressure bad. Of course, it would be loads easier to just check your fuel pressure at the rail with a cheap gauge from your FLAPS.

Before I get ahead of my self, is the pressure regulator in correctly? Are your hoses routed correctly? I gotta ask.

[BiG bOgGs]

OK DrE, thanks for the prescription. (IMG:style_emoticons/default/aktion035.gif) I will check the fuel pressure tomorrow as well as seeing if the injectors are squirting.

I will also check the fuel line routing. From memory, comes from pump to the passenger fuel rail then over to the driver side fuel rail then to the pressure regulator, and then back to the tank. Thats how I intended to route the lines. I hope that is right.
(IMG:style_emoticons/default/idea.gif)

Jim

[Dr Evil]

Yup, that sounds right to me. Just check direction of the regulator as well. Here is a link to a diagram on Pelican that Dave Darling did:
http://www.pelicanparts.com/914/technical_...4_20FI_diag.htm

[BiG bOgGs]

OK, I just finished checking the injectors. I pulled the driver side pair and turned the car over and no fuel spraying. Then I connected my El Cheepo fuel gauge and got a reading of 26 psi.

While I wait for any replies/suggestions, I am going to move things around and see if the wires from the #3 cylinder will fire any of the other injectors.

Jim

[BiG bOgGs]

Back from my little test. I ran a couple wires across the engine bay from the #3 injection wires and connected them to the injectors on the drivers side (which are pulled out of the intake at the moment.) I turned the engine over a couple times, but neither of the injectors fired.


Any one have a webber setup they would rent to me for a couple months until I can get this wiring FI system worked out??


(IMG:style_emoticons/default/wacko.gif)

[Dr Evil]

26 is too low. It should be 29psi and it should hold that setting when the injectors are firing (not drop off). Start there.

So, you said (1) you are getting voltage pulses to the injectors, (2) and you are getting fuel to them I assume.

It sounds like your injectors if they do not open with the pressure increase.

[Dr Evil]

Actually, they should dribble even at the low psi. I am thinking CIS injectors (duh).