Turn the key 2 times to start? Why is my car doing this

[confused]

I have a 79 930 with stock CIS, it seems almost every time I start the car it does not start on the first crank but on the second turn of the key it fires up. I am wondering if it is a fuel pressure issue, maybe one of the ball valves on the fuel pump doesn’t hold pressure? My though is it seems to have the fuel on the second crank but not the first.

Anyone have this issue before? Any suggestions on what system could be out of adjustment?

[Jeff NJ]

Does the 79 have a cold start valve like my 88?
Do you have a fuel pressure tester to test residual pressure?
Does it do this on warm/hot starts, or only on cold starts?

[1979-930]

You are going to need to buy a set of CIS fuel pressure gauges or take it to a shop.
It could be the check valve or the cold start.
Without gauges you'll be throwing parts at it.

[confused]

I am a shop suggesting I take it to someone is of no help, I recently rebuilt the entire engine myself. Just chasing down the last of the problems and looking for someone with familiarity on 930 cis troubleshooting. I know CIS fairly well on early cars but not fully versed in this new modern 1979 version of it.

All the CIS cars have a cold start injector. I haven’t replaced mine or taken it out yet, the thing is my 2 start problem seems to be happening even when warm. If the cold start injector was bad (which they do clog and have other issues) then why would the car start on the second turn of the key. When warm the cold start gets turned off so shouldn’t be an issue then. I am not ruling that out however.

I have pulled the wire on the air meter to cycle the pumps and it seems to help with the start making me think it is a fuel pressure issue. A residual fuel pressure issue however.

On my many mechanical injection cars in the shop we have had this issue, the problem is a one way valve in the fuel filter console let’s all the residual pressure disappear. I was thinking the electric pumps on these cars have the valves built in don’t they.

[T77911S]

you need to verify cold control pressure.
check residual pressure.
the CSV runs off the starter. make sure it is connected.
is the correct connector on the CSV
check valves are usually at the FP.
you have an accumulator that helps maintain pressure after the pump is off but it needs a good check valve to work.

I kind of had to laugh at the " I know CIS fairly well on early cars but not fully versed in this new modern 1979 version ". I would not consider 79 to be a "modern" version. still no lambda.

[1979-930]

The 79 has the check valve at the inlet to the rear pump. It's easy to remove and inspect.