papatioman

Hello all.....enjoy reading all the good information here. I purchased a 1989 C4 with 128,000 miles in October, 2014. Have always had a long crank to start problem with this car. Always runs great after it starts. Here is a list of new parts I have installed in an attempt to fix this.
Fuel Pump, Fuel Filter, Fuel Pump Relay, Injectors, Fuel Pressure Regulator Diaphram, Spark Plugs, Plug Wires, Distributor Cap & Rotor & Ignition Control Module.

Fuel pressure at rail is good at key on and when running. Recently, 2 more symptoms have started. After it is running for approx. 10 minutes it will quit like someone turned the key off. It will restart like nothing happened. This is at idle and driving down the road. The other symptom is not only do I have the long crank before start, it now quits immediately after starting. Does this approx. 6 times before it will stay running.

Scratching my head on this one. Did read some where that the CTS that sends a signal to the ECM may be bad causing the ECM to not realize what temperature the engine is during start. This would explain the quitting immediately after start but what about quitting at 10 minutes into run time. Need a few areas to check here........thanks all!

95BLKVette

Sounds like the Optispark Distributor, any codes?

papatioman

Don't have Optispark.....no recorded codes when I checked with my reader.

ex-x-fire

You need to check fuel pressure bleed down rate too. But that doesn't explain all the issues.
Anyways, can you hook up an inline spark tester? Leave on the car till it acts up. I think pick up coils can act like that.

papatioman

My next step was to replace the pickup coil. Read somewhere that they either work or don't, that's why I haven't done it yet. Will be putting a new one in this coming weekend.

My fuel pressure holds for about 10 minutes after I turn off. I have done the key on first to let the fuel pump prime the rail but same long crank symptom.

Thanks!

aklim

Should be longer for a stock regulator. Clamp off the return and pressurize the system.

Before we go there, Turn it on to run mode and see the pressure and record. Take the FPR hose off, cap off the nipple to the hose and do a WOT and see how much drop.

papatioman

If I get a drop where do you think the leak down is at? I have new injectors & fuel pressure regulator diaphram.

aklim

ASSUMING that those are good, and I am not saying they are not, your pulsator or pump might be leaking. If you go there, get the kit from Racetronix with an extra gasket if you are not replacing the pump.

papatioman

Pump is new and the pulsator has been removed.....not a good practice..I know.

aklim

Why not a good practice? Pulsator is worthless. Just have to go through the steps and see

papatioman

I had a certified mechanic frown at me because I took it off......I agree....just another place for a leak to happen.

Dt86

Actually, replacing the pulsator with fuel line is a preventative measure to eliminate the possibility of having another leaky pulsator.

Matatk

Regarding your long cranking time...this is common on the 89. The 89 was the first year after they deleted the 9th injector and it is programmed to crank longer for fuel reasons. When I had my tune done, I had this crank time shortened. So essentially, you are trying to fix a symptom/issue that can't be fixed with new parts.

As far as dying out, that could be multiple things.

One that comes to mind is the ignition control module. When you replaced it, did you put heat sink paste underneath it?

What is your actual fuel pressure while running and at shut down? Tape the gauge to the windshield so you can monitor it.

You can test the CTS by using an ohmmeter. There is a chart in the FSM for resistance vs temp, it's also floating around on the forum here somewhere.

Are all of your various sensor connections good/tight/no corrosion? How is the wiring?

Lots of things to look at. Do you happen to have a FSM?

Tom400CFI

This would be my first step.

With the spark tester in place (I would hook to coil wire if it has one, to "see" the most sparks), hood open, start the car. As it's stalling (you said it stalls right after start), is there spark?

Tom400CFI

Say what? The crank time isn't an item that is "programmed in the ECM"; it's a by product of how long it takes the engine to start. The thing is a Batch-fire, port FI engine, meaning there is no reason why it shouldn't start on the first or second compression stroke. There is something wrong w/the OP's car, that is causing extended cranking (in conjunction w/his other symptoms).

aklim

Thing is, a lot of the mechanics are GM trained and are only able to follow the GM party line. Sometimes, you need a tuner that not only can recite the book but can understand why they did what.

aklim

It is true that they deleted the cold start injector but they also changed the fueling to compensate for that. Your tuner probably tossed more fuel to decrease the start time.

Correct. Do a WOT run with the FPR hose removed and the nipple blocked to see if the pump can keep up at WOT.

Better yet, get a scanner and see what the ECM sees. Fire an infra red thermometer at the sensor so you have an idea if the sensor is reading right or not. So if ECM sees 100 degrees, your sensor better be pretty close.

aklim

If we are going to test spark, why not do it tonight in a dark garage? He can spray a fine mist AROUND, NOT AT, AROUND the plug wires and see if it lights up. If not, he can test the coil to see if it gives a blue flame. If so, go to the plugs and test at that level.

papatioman

That was my thinking.......

aklim

Many mechanics, if they are even able to diagnose according to factory standards, are considered good. There are a few that understand what is actually happening and can go further so you need to find those shops like the Hitech, Lingenfelter, TPIS, etc, etc.