Airflite40

So I had my car runnin pretty good, but I wanted to refresh the intake. Last winter I did the head gasket and cam gasket, tb. This time round I replaced the intake sleeves, throttle body gasket, throttle body sleeve, CIS housing gasket, installed a brand new CIS housing, new air box to housing gasket....
The car fires and dies. The top part of the CIS housing is brand new, not because the old one didnt work, just that I wanted to replace the gasket and found a brand spanking new top part of the housing for only $40.
I have spark, the distributor is timed correctly. I have fuel now that I put back the fuel pump relay that I removed and forgot to reinstall
I had a friend crank while I watched the engine with the airbox removed. I noticed that the air metering plate was not depressed at all, which would mean not much air was getting in there. The air/fuel ratio is probably way off, but I can fix that with my air fuel meter once I get the car running. Do I need to tweak the rest position of the metering plate, or is it supposed to be all the way up while cranking? The fuel distributor was also rebuilt, injectors were cleaned and serviced, Plugs are new, rotor&cap is new, fuel pump is 5 months old, I removed the decel valve, but I unscrewed the idle screw a lot. The cold start valve is a known good used one. Any ideas??

Dennis Wilson

If the A/F adjustment is too lean the engine will start and die like you are seeing. Try increasing the fuel ratio by incrementally turning the adjuster clockwise. Also, is the air sensor plate centered and is there free movement (with slight resistance) when it is depressed? If those are OK and it still won't start, check the ballast resistors and wires/connections. There are two wires going to the 15 post on the coil. One gives it power during cranking and the other during ignition on running. If a resistor/wire or connection is bad it would also cause the crank, run, die symptoms you are seeing.

Dennis

928BC

I just had my air housing out and re-sealed it last weekend. When I went to start it, no good either.
I could hardly push down on the sensor plate after I had tried starting it. I cracked the pressure and return line @ the WUR and pumped the sensor plate up and down, noting fuel coming from both cracked lines. It evently started and ran crappy, I cracked the pressure line again at the WUR and seemed to run better. It still starts crappy when it's cold, but I think I have a problem with the cold start circuit. I seem to have verry little volts coming from the thermo time sw. when metered @ start.
I 'm going to check the power going into the thermo time sw. today. The reason I got into my air box was because my idle would hunt up and down when the eng. was hot. The re-seal fixed that problem.

SharkSkin

Good advice above. One quick way to check for a lean condition is to push the air plate down a few mm when starting. It won't move much by itself until the engine is actually running. If it belches out black smoke when you start it and it dies, the problem is that it's too rich and depressing the air plate will only make it worse.

With the degree of disassembly that you've done you may need to go through and double-check all pressures against the WSM spec.

jpitman2

Get a copy of Ben Watson on Bosch Fuel Injection systems - cheap from Amazon. Very good diagnostic stuff on CIS/K-jet, including all pressures etc. Mine hunts a little as it warms up, but never when fully hot - maybe a small leak, but not worth chasing yet IMHO.
jp 83 Euro S AT 49k

Rufus Sanders

OK, this may not apply to a Euro, but on my US 82 there are two vac.ports on the throttle body, on the pass. side. They are plugged to block them off. Supposedly they are used in different markets (US, Japan, Austraiia...) for various emission and other vac. related stuff. If the plugs fall out, you get instant lean mixture all the time especially at start, and it will never start until the plugs are replaced.

Getting at them is almost imossible, but it can be done. Replace them with something sturdy, and tight, because if they fall out again, you're dead in the water. I had this exact problem and rememberd reading about this on the nichols site (http://www.nichols.nu/tips.htm) so go there for a really detaied explaination.- Ruf

Airflite40

Well, what I did was took my old cis housing and turned the CO screw to the left at counted turns until it stopped. I counted 12 full turns. Then I turned the one on the car all the way to the left until it stopped and turned it 12 full turns. This should get it close enough to start, but noooo. Now the engine is acting like it does when it is flooded. How long would it take for a flooded engine in low temps (20-30 F) to dry out? Should I just pull the plugs and clean them off? I'm so frustrated... Now all it wants to do is crank and no fire.

Dennis Wilson

Using the old setting probably won't work. After rebuilding my distributor, I set the adjuster at the half way point, then had to lean it in half turn increments to get it to start and run correctly enough to get a good setting. To dry the cylinders remove the fuel pump fuse, hold the accelerator open and crank the engine in SHORT intervals a few times. If the plugs are fuel fouled, you may need to clean them with brake cleaners to get them to fire properly.

Dennis

Airflite40

The distributor was rebuilt before I did this intake refresh, rebuilt in may of 05. I'll try the fuel fuse trick to see if I can dry it out. I'll also clean the plugs as well. Thanks Dennis.

928BC

I know your frustration.
Make sure that battery is @ full charge the next time you try.
Maybe a little insentive down the intake to see if will even fire?

Airflite40

I dunno, I'm hesitant to use "incentive" to fire the car, especially after what happened to Mark Kibort on Scott's engine build. I also heard elsewhere porsches and starting fluid dont mix. I know I have spark since I verified that with a timing light and the distributor is lined up correctly.

FBIII

A way to get the mixture close is to jump the fuel pump and slowly richen the mix till you hear the fuel injectors start to squeal. When they start to squeal lean the mixture slightly so they're quiet and not introducing fuel into the engine. Now try and start it. This worked for me.

SharkSkin

Berryman's B-12 carb cleaner into the intake while cranking will clear gas fouled plugs more often than not. It's not much better for your cylinder walls than gas or starter fluid though. You can pull the plugs, clean them with B-12, crank it with the plugs out( and coil wire disconnected from coil! ) at WOT for a couple/few revolutions. Then put it back together, lean it out a few turns, and try again(don't forget to hook the coil wire back up). It's a lot easier to sneak up on the right mix from the lean side, so this sort of thing doesn't happen.

hupp

I would recommend the method mentioned described by FBIII. This has worked for me multiple times (ie each time I've changed one of the componants in the K-jet system). The squealing injectors will be very obvious. Once the car is running you will be able to tweek the mixture even closer to the correct setting.

heinrich

Dennis Wilson is the CIS King. He helped get my 911 on the road, trust his CIS knowledge like you'd trust Moses on the Ten Commandments.