Went for a drive today since I finally got a day off on a weekend that it's not raining. Had a blast for a good 45min cruising around some back roads. While driving It backfired a few times and had a slight hesitation from coming from a complete stop. It also died once or twice but it didn't have to bad an issue starting back up.

When I got back home it sat for maybe 2 min and then when I tried to move it, it didn't want to start. It was turning over just fine just didn't want to fire up.

It's a 1.8 fuel injected 75. Was told when I bought it, it was upgraded to a 2.0 but I have no proof of that. I also have a huge hole in my muffler which brings me to my next question. I took a muffler from my 72 parts car and was wondering if I can just bolt it right on to replace it.

Any help on where I should start looking for my problem would be much appreciated. I'm sure I'm being a bit vague with my issues but like I said I'm a complete newbie and learning as I go.

It is possible that the hesitation and backfire are from the exhaust leak .
Yes you can use the muffler system from the other car, it will bolt right on.

Noticed that I mentioned muffler system, meaning that you will need every piece from motor to tail pipe. Heat exhangers, muffler, and muffler hanger.

if money and time are issues post a wtb for the correct muffler for your 75' heat exchangers. make sure the hes haven't been backdated prior to buying a different muffler.

Have you tried it again since it cooled down? If it starts and runs fine for about 5 minutes then cuts out again I would check your CHTS!

Search Hot Start. It's a common problem. Multiple threads on a simple fix. On my cell so I'm not searching for u now. Also the grounds need a good cleaning for contact. After 40 years corrosion causes bad starts. Jeff bowsley has a diagram of all the grounds. Sandpaper a file and electronic cleaner them all. A big one next to the starter is the transmission ground strap.

Do this and you'll discover lots about the electrical system.

May I make a small suggestion to the veteran members out there? I promise, I'm not trying to sound crusty here. When we try to help a new guy out, can we try to avoid using acronyms like CHTS (Cylinder Head Temperature Sender). It took me months when I was new just to figure out what the hell people were talking about sometimes That being said, I know nothing about the Fuel Injection (FI) on these cars, so good luck!

To me, it sounds like its running lean. I'm assuming that you have the Ljet fuel injection setup? Check for vacuum leaks, by inspecting all rubber hoses and the rubber intake boot that connects to the air flow meter. I like using a can of starting fluid, and spraying around the rubber vacuum lines. If the engine increases in RPM, then it's likely to be the vacuum leak source. The air flow meter doesn't like seeing backfires, so I wouldn't drive the car till this is all sorted out.

I just noticed that you adjusted your valves recently. How sure are you that these are set correctly? Having the valves adjusted incorrectly will cause a host of problems as well.

Since it sounds like you are not completely sure whether you have a 1.8 (L-Jet fuel injection) or 2.0 (D-Jet), if you post a few pics of your engine bay we can help determine that.

Started right up this morning so I'll clean the grounds today and see if that accomplishes anything. If that don't work I'll see about getting a chts from Porsche tomorrow. On a side note I do remember as I let it warm up yesterday after a few minutes the rpm's dropped a bit and it sounded like it wanted to die a few times. I just figured its from sitting for 2 months or so.

I'm 95% sure I got valves correct this time around! Runs A LOT better now since I did it again.

I'll have to check my parts car again but I'm pretty sure the heat exchangers were rusted through pretty bad so I'll start looking for a cheap muffler.

And I hope this is good enough picture.




Once again thanks for all the help. This site ceases to amaze me with awesome members and a wealth of information to expand my brain and pass the time on slow days at work!

One more pic of air box if that helps any.

A tip that has helped many is this, prior to turning the key to on, press the throttle down completely and then crank. I know it helps on D-Jet, maybe it will help on your L-Jet. This is from the owners manual on how to start your car. Owners manual says use this method all of the time, but it does seem to help more on cars with warm/hot engines.
Owners manual? Who has an owners manual?
Tom

Well, just in case it wasn't clear, that is a 1.8l L-Jet AFC motor as per the picture, unless it is master of disguise.

A couple of suggestions;
1. Completely agree you have some vacuum leak, the hard hot starting, popping/back firing and the idle problem suggest that. L-Jet are fussy with vacuum leaks, and the Air flow control box must sense air moving through the flapper to make the pump run.

2. Your fuel pump should have a ball check valve that holds residual pressure in the line, thus decreasing the time it takes to get your pressure up onec the car is shut off. Check your high pressure side of the fuel curcuit after the car has been shut off to see if it has maintained pressure. Do this with a gauge, NOT be opening the lines on a hot engine. 914 engines like to burn and we don't want to lose another one.

I hope this helps.

Clear to me, as I stated, I know it helps on D-Jet, maybe it will help on your L-Jet !
I agree, looking at the pics from what I can see, there are some aged vacuum lines that I would be checking.
Tom

Stick with the basics before ordering a slew of possibly unneeded parts, unless you're planning on ordering a new vacuum line kit. I'm not doubting your mechanical ability what so ever, but being new to these cars, it's very possible to set the valve lash wrong. Follow Capn' Krusty's valve adjustment procedure, and double check the valves. If this was done correctly, it won't take more than 10 mins to verify measurements. Having one valve set to tight, can cause these problems. After this, start the engine and look for vacuum leaks. These airflow meters are quite expensive, a backfire can cause the internal flap to warp and ruin the AFM.

somebody in the greater seattle area must have a good running l-jet car you can reference and replace the vac lines. in addition to the lines you'll want to replace the cork gasket under oil fill assem and prob the gasket under the fill tower of the assem. see if capn' crusty has 1 set of his NOS oil fill cap gaskets left. look in the classifieds. as noted, the l-jet is very sensitive to vac leaks, low idle and performance suffers.

k

Check out the de-cel valve. I have a 1.8 with a big bore kit, and had high idle that wouldn't drop down. after checking vacuum levels I realized that after warm-up I still had vacuum that was higher than the level that kicks open the de-cel valve (I think I was running 15Hg with the valve open!), and the idle could not be dropped down no matter what I tried. After speaking with Brad Maurer we realized that the big bore kit engine pulled higher vacuum levels, so I plugged up the vacuum line to the valve and BAM, problem fixed. Unfortunately George had been driving this car a lot in a lean condition with that big 'ol valve open and 1700 RPM idle. It's a miracle that there hasn't been major damage (or was there?....)

good luck

Get an Air Fuel Ratio Gauge and this will tell you loads about what's going on.




VERY TRUE! If it is damaged the AFR gauge (see above) will show varying ratios. Definitely try spraying the hose connections as mentioned earlier.

TIP: you should NOT use the gas pedal when attempting to start an L-jet engine.
(Because of backfire concerns)