You can richen it with a ~ 200 ohm resistor between head sensor wire from computer and the head sensor itself. You can find this in any electronics shop. Buy a few different resistances and play around for best idle. Can work on all types of injection with typical head sensor including early with manifold pressure sensor vs flap type air flow sensor on later models. I got a 1971 type 3 VW with manifold pressure sensor (1970 914 had this) to pass California's 2 gas smog test in the late nineties using a 200 ohm resistor. Failed test because it was too lean - low CO percentage (but passing for CO) - thus incomplete combustion so hydrocarbons parts per million real high. That's why it flunked. Resistor solved it by increasing CO percent slightly thus lowering hydrocarbon output. Car passed. It idled cold (and still does) as if the engine is being rotated by an electric motor - super stable idle rpm. Super smooth. Don't even try to mess with the screw in manifold pressure sensor. The type 3 is still driven daily. I built the engine in 1996.
Gary, thanks for the fast response to my question. I've looked at that website before and it hasn't helped me so far. I'm unable to get the injectors to hardly fire. If you have any further suggestions that may help I would greatly appreciate it. Thanks again, Jim
Hi Gary I have a 76 2 liter. It has idle issues. I’m going to use your suggestion and put a fuel rail screw in the cold start valve. In the meantime I’ve noticed the idle air fuel screw on the throttle body sucks air in thru the screw threads. What little info I can find on the D jet system says that these threads are sealed with something. Do you know what they used to seal the threads?
Hi Richard. Off the top of my head I know of no sealant used for those threads . I can't seem to find a parts explosion to research but I don't even think there's an o ring on that screw. As I remember, if anything, there's just a tension spring. If yours is passing air it's probably because it's too far out. If that's what it takes to make your car run, I think there may be other problems in the system this is compensating for. I'd assume you are dealing wit a "hunting" problem. It seems that 90% of F.I. issues have to do with vacuum leaks. I'd check for any of those issues first. Check all your hoses Also, check for leaky injector seals. Put a vacuum gauge on the MPS and see if it will hold 10 pounds of vacuum. Once you are confident there are no other vacuum or intake leaks verify that your Vacuum advance is working properly and that the advance plates are moving and returning smoothly then re check your timing and idle screw adjustment. But if you like, I'm sure a bit of grease on those threads won't hurt anything
Gary, I am not a mechanic!! However, I need to change my fuel filter. I have a '74 914 1.8 with fuel injection. My problem (one of them) is I cannot find the fuel filter. Any tips? Thanks, Marv
I'm working on a 1976 914. I have had the motor out and reinstalling it I can only get it to fire with the throttle fully open and it only runs for a second. It has good fuel pressure and the car ran good before I took the motor out. I changed points, condenser,spark plugs and wires. The car will run a little if you put a little gas in the throttle body. I live in a small town in West Virginia and finding someone to help or with any knowledge is impossible. Is there any way you may be able to give me any help or suggestions? It would greatly be appreciated. I'm a 65 yr old muscle car guy that doesn't know much about fuel injection so any help would be great. Thank you very much, Jim
Hi Gary trying to get a 1973 914 running for a friend of mine was running recently, he tried to start will not run, smell fuel, below air mixture butter fly in fuel injection, lake of fuel, normal? sorry no Porshe experience at all thanks in advance
I had the same problem. It was the cold start injector. I live in a warm climate so I don't need it. Get that fuel out of the plenum. Dry it out. Then try disconnecting the fuel lead to the cold start injector and plug it. Remember this is a high pressure system so make sure your plug doesn't leak. The best way is to get a fuel rail screw from 914 Rubber. It will screw into a tap in the fuel rail between #1 & #2 cylinder. You can put the cold start injector fuel line back on over the plug to keep the engine original looking. Hope this helps.
Fuel rails are between the injectors and spark plugs where the manifold tubes meet the head. Cylinders 1 & 2 are on the driver's side. Cold start injector is in the rear of the plenum. Follow the fuel line from the injector to the driver's side fuel rail. Plug that hose.
cleaned the leaves out of it, (why i couldn't see sh##), plugged fuel line, dried it out, running now, might look into why injector is stuck, most likely doesn't work often, seized. Thanks again for your help !
You can richen it with a ~ 200 ohm resistor between head sensor wire from computer and the head sensor itself. You can find this in any electronics shop. Buy a few different resistances and play around for best idle. Can work on all types of injection with typical head sensor including early with manifold pressure sensor vs flap type air flow sensor on later models. I got a 1971 type 3 VW with manifold pressure sensor (1970 914 had this) to pass California's 2 gas smog test in the late nineties using a 200 ohm resistor. Failed test because it was too lean - low CO percentage (but passing for CO) - thus incomplete combustion so hydrocarbons parts per million real high. That's why it flunked. Resistor solved it by increasing CO percent slightly thus lowering hydrocarbon output. Car passed. It idled cold (and still does) as if the engine is being rotated by an electric motor - super stable idle rpm. Super smooth. Don't even try to mess with the screw in manifold pressure sensor. The type 3 is still driven daily. I built the engine in 1996.
I have had three of these cars love them
Gary, thanks for the fast response to my question. I've looked at that website before and it hasn't helped me so far. I'm unable to get the injectors to hardly fire. If you have any further suggestions that may help I would greatly appreciate it. Thanks again, Jim
email me your phone number Gary@musicmagic.biz
Great video, Gary. Thanks for sharing this. What color is your 914? Looks like a Phoenix Red one I had.
Hi Gary I have a 76 2 liter. It has idle issues. I’m going to use your suggestion and put a fuel rail screw in the cold start valve. In the meantime I’ve noticed the idle air fuel screw on the throttle body sucks air in thru the screw threads. What little info I can find on the D jet system says that these threads are sealed with something. Do you know what they used to seal the threads?
Hi Richard. Off the top of my head I know of no sealant used for those threads . I can't seem to find a parts explosion to research but I don't even think there's an o ring on that screw. As I remember, if anything, there's just a tension spring. If yours is passing air it's probably because it's too far out. If that's what it takes to make your car run, I think there may be other problems in the system this is compensating for. I'd assume you are dealing wit a "hunting" problem. It seems that 90% of F.I. issues have to do with vacuum leaks. I'd check for any of those issues first. Check all your hoses Also, check for leaky injector seals. Put a vacuum gauge on the MPS and see if it will hold 10 pounds of vacuum. Once you are confident there are no other vacuum or intake leaks verify that your Vacuum advance is working properly and that the advance plates are moving and returning smoothly then re check your timing and idle screw adjustment. But if you like, I'm sure a bit of grease on those threads won't hurt anything
Gary, I am not a mechanic!! However, I need to change my fuel filter. I have a '74 914 1.8 with fuel injection. My problem (one of them) is I cannot find the fuel filter. Any tips?
Thanks,
Marv
I'm working on a 1976 914. I have had the motor out and reinstalling it I can only get it to fire with the throttle fully open and it only runs for a second. It has good fuel pressure and the car ran good before I took the motor out. I changed points, condenser,spark plugs and wires. The car will run a little if you put a little gas in the throttle body. I live in a small town in West Virginia and finding someone to help or with any knowledge is impossible. Is there any way you may be able to give me any help or suggestions? It would greatly be appreciated. I'm a 65 yr old muscle car guy that doesn't know much about fuel injection so any help would be great. Thank you very much, Jim
Hard to reply with much info here but here's where I would start. members.rennlist.com/pbanders/djetparts.htm
Hi Gary trying to get a 1973 914 running for a friend of mine was running recently, he tried to start will not run, smell fuel, below air mixture butter fly in fuel injection, lake of fuel, normal? sorry no Porshe experience at all thanks in advance
I had the same problem. It was the cold start injector. I live in a warm climate so I don't need it. Get that fuel out of the plenum. Dry it out. Then try disconnecting the fuel lead to the cold start injector and plug it. Remember this is a high pressure system so make sure your plug doesn't leak. The best way is to get a fuel rail screw from 914 Rubber. It will screw into a tap in the fuel rail between #1 & #2 cylinder. You can put the cold start injector fuel line back on over the plug to keep the engine original looking. Hope this helps.
@@garycotton thanks for your quick response, my bud says he has repair manuals, which I am going to need. I don't even see the fuel rails, DUH HA HA
Fuel rails are between the injectors and spark plugs where the manifold tubes meet the head. Cylinders 1 & 2 are on the driver's side. Cold start injector is in the rear of the plenum. Follow the fuel line from the injector to the driver's side fuel rail. Plug that hose.
@@garycotton thank you
cleaned the leaves out of it, (why i couldn't see sh##), plugged fuel line, dried it out, running now, might look into why injector is stuck, most likely doesn't work often, seized. Thanks again for your help !