CIS troubles on a new Engine!

[jwernquist]

Alright so i installed the new motor this weekend! Got up oil pressure connected the coil turned on the fuel pump and let er rip!

Almost started! Then died . Rechecked my fuel lines since after some cranking i smelled gas! Bled the air out of the CIS and tried again!

Chug Chug POP start die! ANd now its flooding? DIsconntected the cold start thinking that might be giving it too much gas! Still the same thing!
Flooding? Weird huh!

I'm thinking my return fuel line might be clogged ? Would this cause too much gas in the CIS?
Or could the CIS be that much out of tune ??

Im at a total loss i didnt think CIS was very difficult!

Any advice i could get would be greatly appreciated!

[jwernquist]

The engine is a fresh rebuild the CIS system is used and has been sitting for some time. The only thing done to the CIS was installing a few new parts here and there?

Any Ideas!

[cowtown]

Does the piston in the fuel distributor move freely? That was causing the same esymptoms when I put my 930 engine in. It was stuck open.

[911nut]

Check the fuel distributor. If it sits dry it will corrode.

[jwernquist]

Thw air flap moved freely? IS that what your referring to or should i remove the FD and clean and go through it?

When i would press the air flap upwards i would gett a rather large spray of fuel from the fuel injectors i check only a couple of them. One seemed a nice small spurt the other seemed to spurt much more gas ???

[vash]

if the fuel only sprays when the airsensor bar is pushed up, the FD is fine. peek into your pop off valve, is there a huge puddle of raw fuel?

[Paulporsche]

The injectors should all have an even, conical chaped misty spray.

If you clean the FD be careful the plunger does not fall out of the bottom when you remove it. Check for rust or varnish deposits.

Make sure the mixture control flap is moving freely and is not dirty or greasy.

[Jim Sims]

Why do you think it's flooding; sounds more like an airleak to me. What does "POP" mean? Was it a backfire? Does the air box have a pop off valve? If so check that it's seal is in place and that it's seated. If the wiring is hooked properly the cold start valve (CSV) should only operate while the starter is cranking. If the cold start valve is disconneted you will have very hard time starting. I'd hook it back up. Back sure you're using the correct plug for the cold start valve and air flow switch. Blue plug (or marked with blue dot) to CSV, green plug or dot to air flow switch. Jim

[jwernquist]

I'm pretty sure if flooding. The car fired up today first crank! Then died i continued to crank it over and after 10 seconds of almost starting! I would smell fuel. I looked into the airbox and there was a few drips of fuel in the airbox and also some leaking from a seal on the Heat exchanger ? I pulled out the plugs and they were soaked in fuel!

I'm going to double check and make sure my fuel return line isnt clogged! Hopefully thats is but im not quite sure?

[Paulporsche]

How do you provide enrichment for cold starting and running? Do you have a thermotime switch, a WUR, an AAV and AAR, or do have the hand throttle from early CIS?

Paul

[Paulporsche]

Have you checked your points/dwell?

How about your CO?

Paul

[konish]

fuel system pressure? Maybe bad injectors. The CIS continuously injects fuel (as you probably already know) but the injectors should not open unless there is at least 40#'s of pressure behind them (from memory). If your injectors are corroded, they may be stuck open....? No expert here, but excess fuel may be a result of your cylinders filling with raw fuel as the injectors dribble gas....

R/
Dustin

[vash]

i had the exact same symptoms, very strange. mine was the control plunger was stuck. but you get a feel off of the air sensor bar right? there is resistance when you push up? it is really easy to take off the three screws that hold the FD on and lift it to take a peek to see if the plunger is stuck. but i dont understand your issue. strange!

cliff