mrhude

Always check and recheck the basics first!!!! Start witht the valve adjustment, points adjustment followed by an actual dwell meter, basic timing, and then sweat the FI issues. 9 times out of ten it will be something simple that you overlooked. Get in the habit of checking the basics first and then tackle the fuel injection. Like my old instructor used to say you got to have fuel, air , and fire. Check the basics!! Good luck . . . .

hitbyastick

Spark is there.
I believe the lack of power is directly related to not getting enough fuel. I pulled the spark plugs and the electrode is clean, like new, and the little hook thingy for ground is white. That would imply a lean condition, yeah?

Also did a compression test and it's even on all cylinders, that would rule out a sticking valve, right?

I think that gluey stuff really messed up my injectors.

cobalt

Sounds like your figuring it out by yourself. Smart thought on the compresion test. I didn't think you had a tester.

I never got around to looking for the info in the manuals. Do you have a set? I can try to this weekend. If you PM me a fax number I can send you the info if you don't have it.

Odds are gooey fuel gummed things up. You can also try some of these fuel additives/cleaners.

killbugsfast

Are the intake runner boots old and cracked ? Is the vacuum pressure regulator OK ? I had myriad problems with my 74 2.0 FI and it ended up being the Pressure Regulator . Swapped my friends for mine and the car was fixed so I ordered a rebuilt one . They are not cheap.

hitbyastick

bug killer,
the intake boots are new. Vacuum pressure regulator? Wheres that? Is that the little tee that comes off the cylinder head vents?

killbugsfast

Nope . It is the round silver part, about the size of a can of soup, mounted on the engine support rail on the passenger side. It has a vacuum line coming from the intake to the frt. of it and a wire with 3 contacts going to the back of it from the ECU. According to the vacuum values , this part together with others decide on the duration of the injection time. The points in the distributor (FI points below the ignition points) give the actual timing of injection. By the way, the air temp sensor is regarded by most as useless and not needed. Go ahead and disconnect it and see if your problem improves. It is located below the air cleaner, mounted in a vertical way. It is a wire with a plug with 2 contacts inside. Your description does not suggest cold start valve problems. There is a 914 FI troubleshooting guide somewhere around here. It helps you find out what component is out of specs. What you do is remove the wire loom connection to the ECU and test with a voltmeter to the specific pins listed to each component and see if the resistance is within specs. I am relatively new to the Rennlist so I do not know if this troubleshooting guide is in the DIY library. If not and you still need help , let me know and I can look for my copy and fax it to you . Also , after the Pertronix caused problems until one day it just burned , I went back to points and condenser , as my mechanic recommended and have never looked back . Let me know if this helps . By the way , I think there is a pressure regulator in my shed somewhere . I can not remember if it works but by just swapping it in my car it would be easy to tell .

killbugsfast

Oops , let me correct that . The wires to the VPR go to the frt. of it , like the vacuum line . The back of the part has the adjustment screw sealed in epoxy from the manufacturer . I have heard it is possible to repair them but must mechanics shy away from it . It invoves setting a very fine air gap ?? I think you are expected to ship your used one as core .

hitbyastick

Oooh the manifold pressure sensor. Yeah i checked that
Thanks though.

hitbyastick

I pulled the injectors. Two of them were squirting fuel. But it was more of a stream than a mist. The other two only trickled every once in a while. So I removed them, cleaned them and put them back in. 3 of them now fire a nice mist. One of them doesn't do anything at all. I switched connectors with one of them and what do you know, that one does work. So now I have to go back to wiring problems because I guess one of the connections is lose, or a wire broke or something causing no pulse on the injector for the number one cylinder.
I don't really want to cut open the harness. Do you think I have to? I have a multimeter. Aside from the wiring, what else would cause one injector to not fire and the rest to go off just fine? ECU?

cobalt

OK so you switched the harness and the one injector works with the wrong cylinder harness attached. Did you connect the harness that was not working to an injector that you know was? Does it work? If so it is not the harness. If it leads to the harness. I would check for damaged wires or connector. It may just be it was not plugged in correctly, if it is the harness and you don't want to cut apart your existing harness let me know I believe I have a complete engine harness in good condition I can send you.

It sounds like the majority of your problem has been resolved with the injectors not feeding enough fuel. My concern is that if you have a lot of gunk in your tank the filters will not prevent this from happening again. You may need to think about flushing your tank.

hitbyastick

I'm assuming the harness is the problem. If I plug the connector from the #1 fuel injector into the #2 injector, that one doesn't fire either.

However, if I do a resistance test with a multimeter they both read the same resistance. What could that be? I think that one injector has been the culprit all along. The #4 injector is on the same circuit on the current flow diagram. Where is the connector?

What causes the injectors to fire. A pulse from the ecu, yes? Is that it?

I can move the throttle switch with the inginiton on and the #2 injector will fire. Or I can turn the key and it does it's start up squirt. But nothing for #1.

hitbyastick

Okaay .. this is really starting to bug me.

I changed the ECU, same problem.

I cranked the fuel pressure regulator to almost max. and it made the car something close to drivable.

I pulled all 4 plugs and they look very lean.

I measured the resitances in the MPS unit. They are fine, and the vacuum thingy works.


Man I just want to drive the damn thing.

cobalt

Off the wall question. Is your throttle cable snagged in any way? If the cable gets hung up it will leave the throttle open a very small amount. This will throw everything off and as you attempt to make adjustments you just keep throwing things further out.

Worth a look at this point.

hitbyastick

What would cause the engine to have a completely lean condition?

Clogged injectors? Sure ... but all four equally?

Faulty MPS? Maybe but usually when those fail the mixture get's rich. I'll try to run it without the vacuum.

The injectors certainly fire, but how about at the right time? Maybe the intake valve is already closed? Is there adjustment in the trigger points?

Faulty temp sensor II? It runs about the same at any temperature though. And I replaced it.

robertj

Sounds very similar to the problems I'm experiencing. No power at anything below 3500 rpm. I replaced bad injector, distributer contacts look brand new, timing seems to be set correctly, new fule lines, new fuel filter. Ran great for 2 weeks when I bought it 2 months ago. I threw out the old fuel filter by mistake, so was unable to check for gunk- might have to take off the new one to check, but don't think that that's the problem because I after puting in new plugs last night (the old ones didn't look that bad, but had them on hand) the car ran great for about 2 minutes, and then reverted back to bad form.

Need to check for vacuum leaks still. ugh, summer is flying by and no convertible to drive in!