hard start

[dsm_94_4ever]

Checked on the forums and cant find anything thats like my problem. Here's my problem when I try to start the car the moter cranks over for about five seconds then starts picking up faster and faster and will finally start.The car runs fine once it has started no CEL but when you turn it off and its warmed up its even harder to get started again.Its acting like it has no fuel in the rail but once you crank the moter for a while it builds pressure and then starts.I have herd it could be the check valve in the pump or injector O rings but im not sure how to test either without just buying new ones.If anybody knows whats going on or fixed this problem before please let me know thanks.

 

[cliffkemp]

check you coolant temp sensor...it could cause this issue.

 

[ericemery]

Also, are you on the stock pump or have you switched over to a walbro?

I just went through a hard start/no start with my 91. it ended up being a combination of things, but the Engine coolant temp sensor was the main culprit.

They are easy enough to test if you have a multi meter. just test the resistance of the sensors 2 prongs. (its the lower sensor by the single prong sensor. that single prong is for the gauge cluster temp reading. the prongs look like a T.)

If the resistance is real low. (sub 1500) or real high (above 5000) ohms, your probably looking at a dead sensor. If the sensor tests out fine, double check that you have continuity at the ECU. connect the 2 connectors together at the sensor, (with it unplugged obviously) and verify continuity at pins 20 and 24 at the ECU. The big plug, bottom row. looking at it, they will be the first and fifth pins. (black with green stripe and yellow with green stripe.)

Hopefully this will at least eliminate that sensor as the issue.

 

[dsmike1]

Could also be a restricted (dirty) fuel filter

 

[DSM1G90]

either vapor lock, or an ECU getting ready to die....in which I had both and cured the first initially, but the latter finally took me down.

After the ECU replacement, no more hard starts when hot.

But I still have the slightly long crank until it fires and I know it's due to the check valve in the stock fuel pump has a crack in it causing the pressure in the line to drop when I turn off the motor. Thus, when I hit they key every time, the pump has to run to get the pressure back up in the line to get the injectors to fire.

 

[dsm03]

Do a Compression Test. Possible ignition coils as well.

 

[BoostedBen]

Have you checked base timing?

 

[Abe'sGST]

basic things first, check your fuel filter, maybe be dirty like mentioned above

 

[dsm_94_4ever]

The car has stock pump whole car is pretty much stock.The way it acts really seams like its losing fuel pressure when the engine isn't running but I could be wrong.

 

[DSM1G90]

There is a simple test to check for fuel pressure and if pump is working:
There is a small connector in the area of the ECU grounding connector, that is wrapped up in the harness next to the firewall which is right behind the battery.
The wire that is attached to this small connector is a direct line connect for the 12v feed to the fuel pump.
You put a wire in that small connector and touch it to the positive post to the battery.
You squeeze the fuel line from the filter while you touch the wire on the battery and you should feel fuel pressure suddenly build up in the line. Fuel is running across the rail and exiting out on the other side back past the regulator and back into the tank.
Release the wire and the pressure should suddenly drop.

 

[dsm_94_4ever]

Ok so I pulled the fuel line off the top of the filter today no fuel is pumping out when you turn the key to the on position.Correct me if im wrong but shouldn't there be gas pumping up to the fuel rail when the key is on the on position?DSM1G90 could you get a picture of the connecter to the pump your talking about?

 

[cliffkemp]

Ok so I pulled the fuel line off the top of the filter today no fuel is pumping out when you turn the key to the on position.Correct me if im wrong but shouldn't there be gas pumping up to the fuel rail when the key is on the on position?DSM1G90 cold you get a picture of the connecter to the pump your talking about?

My pump doesnt come on til you try to start. That is how the pump works in my 90 model.