racerx7

You are describing a restriction problem from either fuel or exhaust. Since this a 1974 car without a cat and there is not much to your exhaust system I am going to assume it must be a fuels system problem. I would install a fuel pressure gauge out side of the drivers compartment and take the car for a drive and watch the gauge. I do not think you are getting enough fuel pressure. You mention that you changed your fuel filter and that it was very dirty even though it was just changed a few weeks ago. I think you have a winner right here. If you filter clogs after just a few weeks your gas tank and lines must be full of crud, hence low fuel volume. I think it is time to take a look inside of your tank.

goose2

'74 is L-Jet fuel injection I think. A vacuum leak in the system anywhere will make it run lean...which might explain why increasing fuel pressure improves it. Just another area to check out.

hitbyastick

goose, 74 2.0 is still D-jet. I went through all the vacuum stuff anyway and it helped a little. Nothing worth mentioning though

racer,
i checked the fuel tank and it's clean as a whistle. I can't speak for the fuel lines, however.

I don't know, I'm at a dead end. Maybe it's just in my head ;-p

hitbyastick

Allright, so I'm at it again.

I did another compression test. The intake valve on the #1 cylinder seemed to be too tight as well, so I adjusted everything. Then I did another test and the #1 cylinder is at 91 PSI. All the other ones are at ~145 ish.
I have european pistons, so that's probably not a good thing. Could this be what's wrong with my car?


I'm getting about ready to drop the motor. Redo the heads, redo the piston rings, put in an agreesive cam, lifters, pushrods, do a bunch of headwork and rev it to 8K with a set of Weber 40IDFs.

What do you guys think?

cobalt

Did you check to see if the rocker arm was sticking? I would start there. Dropping the engine and pulling the head on the 914 is relatively easy. You may need to try this but I would check to see if the rocker arm is sticking leaving a valve open first.

hitbyastick

What would I do if a rocker arm is sticking? What if it's not? I heard 2.0 heads crack easily and have valve guide issues. Could that be the case?

Would it make my car run lean because the manifold pressure is different?

swl

Hey Christoph. My first visit to this board and your thread caught my interest. I really don't have a lot of mechanic background but I have spent the last couple of months (damn - has it been that long! - my job is getting in the way of my hobby!) restoring fuel delivery to my teener that has been parked for :wince: 20 years. Any chance this car sat for an extended period of time before this problem arose? That stuff that is sticky like glue is residue from evaporated gas. In mine it was so bad that the return line was fully blocked with the stuff. It was just like tar. You can smell it in the gas too - smells like varnish. If you have a partial blockage in your line I would expect it to work reasonable under low throttle and start to starve as you need high gas flow. Just like those stupid flow restrictors in shower heads these days. I would recomend that before you go tearing down the engine have a look at your fuel delivery. See what your fuel pump is doing for you.

swl

That is probably pbanders from this site. http://members.rennlist.com/pbanders/

I just found his work yesterday and it is an absolute 'must read' if you are troubleshooting fi.

hitbyastick

Thanks man, that's a great resource. I'm currently trying to find a better place to work on this engine. First I gotta see why the compression dropped. It ran a lot hotter than it was supposed to one day, because it was way lean, and I guess that happens.

I read a great deal of info on the site and there's some hope yet. I have a few items on my list that I need to check out on the car.

swl

Good luck on the search Christoph. Trying to work without a proper space is gonna drive you nuts. Wonder if you could swing some sort of deal with a local high school shop teacher? Your car is interesting enough that he (she?!) might be willing to take you on as a student project.