Hello all, first time poster here. long time Porsche owner but no 914's for the last 20 years. just got a 74 1.8L. Not running. been sitting for a few years. looking for some advice on getting it started. here's what I have done so far:
drained fuel, cleaned up pump and contacts. replaced filter and lines here. R&R AFS, throttle body,air dizzie, cleaned. replaced all vac , fuel hoses. checked fuel pressure= 40-- holds 20 for about 20 min.. new points,condeser,cap,rotor,wires,plugs,static timing. check compression---140-160.
cranked it up, starts, revs once, then dies. then crank crank crank ---nothing.
wait ten minutes. does the same thing. checked all double relay functions, connections---everything OK. replaced relay anyway, looked bad. R&R all ground connections. ALL of them. still does the same starting drill. R&R and check operation of aux air valve,throttle switch,cold start valve thermo switch. evrything OK except thermo switch a little sketchy. jump thermo switch plug with 12v and ground, engine starts , runs poor, dies when jump is pulled. pulled ECU connector do voltage supply tests from manualstype4. all OK. rehookup all wiring, pull injectors, crank with ign on--- no fuel spray. pull ECU connector and injector plugs 12v at all plugs--- no shorts. apply ground to #14/15/32/33 and get good repeatable fuel spray test. 50---70 cc at 20 sec. hook up ECU, crank + ign = no fuel spray. jump coil#15 and starter #50 w/12v (bypass ign sw). crank= no fuel spray.

I'm at the wall here. ECU?
also, one of my VW manuals talks about replacing the 15C thermoswitch with a later 35C unit to help starting problems. makes sense to me. comments?

TIA
Randy
Bellingham Wa

Sounds like you are on the right track....

Did you check to see if the white wire is on the negative side of the coil? It should come from the injection harness. It starts on the fuel from the cold start valve.

yes, It's there and has continuity to the correct plug in the ECU connector.

Sounds to me like your ECU doesn't know the engine is running. Revisit that coil sense lead again. At the risk of stating the obvious, it should be connected to the points side of the coil.

Well; after reading all the comments about John's similar 1.8 situation, I went back to the garage and checked static timing, points gap, and spark. a big fat blue spark at all four plugs. the #1 white wire is connected to coil #1. it has continuity to ECU plug #1. Ecu plug#10----#17 = 12v. I think I have ignition and the ECU should know about it. I have plugged and unplugged the ECU connector several times (with the battery disconnected), cleaned both sides with contact cleaner, inspected the spades for bending. it seems to snap in place like it should.

My 1.8 had 3 seized fuel injectors.
Take them out and with a pointed tool see if you can move the injector pintle. You should be able to "feel" it click in and out. It doesn't take much force to move it in/out

It sounds like you may have a rare bad ecu. I have seen one in my 24 years of working with these cars. Same problem. No start, no injector pulse. And truly the ecu was not bad. Someone had changed it out for the one from an L-Jet Beetle. It has some different pins in it.

Does a noid light flash when hooked to the injector leads while cranking the car?

I would pull injectors and verify that they are pulsing. If not, verify that you are getting power to the injectors. You may only be getting fuel through the cold start injector. Power to the injectors in dependent on the lead coming from the negative side of the coil.

This may sound crazy, but be sure you haven't had any hoses on the big rubber elbow come off and just have a large vacuum leak causing the AFM to stay closed (cutting off fuel). I can't tell you how many clients have had their cars towed in to my shop only to have a hose on the elbow pop-off. Gives symptoms similar to what you describe. . .

Mark; thanks, my injectors are working(see my first post). I have to manually fire them with jumpers to the ECU plug.

Nate; thanks, I have the injectors off. they have 12.3V to them with the ign on. when cranking, there is no pulsing, clicking, voltage drops off to 11.1-10.9V. I can get them to spray by grounding #14,15,32,33 on the ECU plug. I'm thinking the injectors are OK. just now I ran a 6GA ground from the battery ground strap to an engine mount bolt and renewed the terminal on the #1 white wire on terminal 1 of the coil. Ign on, crank crank crank= no fuel spray, no clicks, no pulse. good spark. new vac lines all hooked up. the cold start valve is clicking OK. Is there a way to confirm the ECU is getting ign signal with the connector pluged in? what is the correct ECU # FOR A 74 1.8l?

PET figure 901-05 #(8) 022.906.021 G lists a control unit up to engine serial number EC0 037 552 then 473.906.021 control unit from engine serial number EC0 037 552. Perhaps the difference is 74 and 75 model years.

I had a similar situation. I was doing some work on the AFM and forgot to re-attach it. Car would start fine but as soon as I stepped on the gas pedal, the car died. Plugged it back in and it was fine.

Yours is obviously connected, but maybe the AFM itself or harness connector could be bad.

Jim, Nate; thanks yes my AFM is attached. resistance #'s are spot on. harness continuity to ECU plug is perfect. I think. I'm going to recheck that.

Hey, I'm not alone in resuscitating a 1.8FI.

Click to view attachment
Thanks everyone for the advice on my L-jet troubles. I was able to get a known good used ECU. swapped it out, checked injectors, now I have fuel. reassembled everything and sucker started right up. idles nice, pulls strong in all gears to 4500. man , when this system works, it works great!. lesson here is the ECU can fail, mine did.
Thanks
Randy

Randy, glad to hear your perseverence paid off. Congratulations. Regarding the ECU, it's possible that you had an ECU that was mismatched with your AFM and wiring. Did you verify the part numbers on the two ECUs?

Again, good work on getting your engine to run. The Ljet FI can be a remarkably effective and reliable fuel system, once you've eliminated all the little bugs.

PS. Your car looks great. Now just ditch those wheels for some proper factory alloys and you'll be set.

Nice work. Car looks great. My '74 1.8 was in storage for years and had Rivi's and the same side decal as well. The owner bought new from University Porsche. Did yours come from there too?

Dave; yes the ECU #'S were correct, and hey, I kind of like those wheels.

Nate; yes this car was sold new at university Porsche. I have most of the records going back to that dealer. the car has the 8-track and manual installed by them. I have the original service records from U Porsche as well as some original cool promo items from them, cards, maps, matchbooks etc.

took the car out on the freeway today for the first real hard drive. pulled great up to an indicated 90, seemed like there was a lot more in it. ( speedo maybe a little fast?) rolled smooth and quiet at 80.
Randy