I picked up my '86 automatic car with 129K miles on it a couple weeks ago. I've only driven it about 4 times since I got it and everything has been fine. It just got cold and this morning it was hard to start. Then same thing again this afternoon.

My procedure is turn key on and wait a few seconds for the dash to do its thing and display normal, then crank over engine. It cranks but doesn't fire right away. I had to pump the gas pedal a couple times and it finally fired after about 10 seconds of cranking. I've never had a fuel injected car that had to pump the gas pedal car like a carb'd car. Once it fired it ran normal.

I drove it about 5 miles then it sat until late this afternoon. Did same but when it fired it died right away. Did this three times and then finally fired and stayed running but I had to feather the gas pedal a few times to keep it running. After that, it ran fine again.

Fuel pump getting tired maybe? I'll try it again tomorrow morning and cycle the key a few times before cranking and see what that does. Any other ideas?

 

Okay, no replies?

I tried starting it again this morning. Turned on key and waited about 10 seconds. Could hear fuel pump kick on for maybe 3 seconds then shuts off. Turned key off and on again but did not hear fuel pump. Did it two more times with same results.

Then cranked for about 3 or 4 seconds and no fire so pumped throttle. It fired for a second then died. Did this twice before it stayed running but I had to keep feathering the throttle for a few seconds. After that it ran fine. Smooth with no stumble.

I admittedly have not checked anything yet. I have no idea when the last time a tune up was done so new plugs, wires, dist cap, etc is on the to do list. Also figured I try Seafoam. Maybe that will cure it?

 

cold start injector - assuming the 86 has one.

 

I’ve been dealing with the exact same issue on my 88, I started a thread about it back in August and I’m still working on the issue, but it seems to be the Cold Start Injector, I ordered one and will hopefully have it next week. What kept me from thinking it was the CSI is that I kept hearing a lot of people say they got rid of theirs with no issue, but there is a little more to it than just disconnecting it. Anyways I’d check to see if you’re getting 9.5 volts to the purple wire at the CSI connector while cranking when the car is stone cold, and go from there.

 

I will check that. Thanks!

 

Have you checked the basics? Spark, Fuel, Air.

Recommend checking the fuel pressure first, simple, easy and quick with a $12 gauge. The CSI is supposed to help start when cold, but pumping the pedal says to me check fuel pressure right away. Search the forum for details.

Certainly don't recommend swapping parts right away, even new stuff can be bad out of the box.

 

After that, check for continuity of the CSI by disconnecting the electrical connector to it and reading the resistance value of the injector. Not sure what the value should be but at least check for continuity(open or closed circuit) for starters.

 

I too have the 9th injector, or the Cold Start System on my 1988 L98 engine. I have had my share of issues with the Cold start system they used in the L98 engines. It is a nice way to start the engine when it is really cold outside. When it works, it is great, when it fails then the fun really starts as the control system is a bit over-complicated. Using the charts in the Factory Service Manual you should be able to troubleshoot the cold start system. First check the fuel pressure and be sure it is correct before going any further!

One of the most important things on the early EFI cars is to be sure that they make the correct fuel pressure. There was bad corrosion causing a voltage drop in my electrical system and that affected everything electrical. Once the fuel pump had the right voltage going to it I had the required 43 psi. Then the engine would start right away and stay running. To check your Fuel pressure we suggest that you find a fuel pressure gauge with a long hose. You attach one end to the fuel rail and it should indicate what pressure your engine is seeing on the gauge. Next tape the gauge to your windshield so you are able to see it while driving the car.

On my 1988 I had an issue with rust inside the fuel lines and it blocked the flow. I ran a temporary hose around it and the engine started and ran fine. I was getting the correct pressure but insufficient Volume which was a real PIA to troubleshoot.

 

When the ignition switch is turned to the crank position power is sent to the purple and white wire of the cold start timer switch and the ninth injector. The timer switch controls the ground side of the injector.

 

Will it fire off with the pedal held to the floor ? This is clear flood mode

 

I haven't seen this version of the CSI troubleshooting chart before. Thanks for posting it.

I LIKE the initial test for pressure drop in the first step. Note that the third bullet is "disconnect the distributor 4-way connector". << This is to disable reference pulses from reaching the ECM. If ref pulses are not disabled, the fuel pump will run as soon as the engine is cranked, invalidating the pressure readings.

I will add that coolant temperature is super important. If the thermo time switch has opened because it is 95F or above, the test will not validate the injector itself, just the entire system. So 'my way' of applying 12V directly to the injector while watching the pressure is a more definitive test of the injector itself. If the injector is ok, then further testing of the thermo time switch is necessary.

I don't understand ctmcloskey's comment "as the control system is a bit over-complicated." What? The 90-96 fog light circuit is more complicated. There's only two components, two wires and a fuse. It isn't ECM controlled, and is only powered when the key is in CRANK. The L98 CSI system is identical to the CSI system used on air-cooled fuel injected VW and flat 4 914s in the late 60s, early 70s. This very simple, effective first start aid has been around a long time, because it works.
He also says "It is a nice way to start the engine when it is really cold outside." I've never considered 95 deg F to be "really cold". Actually 95F is "hot" to me. But the L98 needs the CSI for easy starting at up to 95F.