"Starter Turns Engine, but it will not Start"

[Norman123]

Hello everyone, First and forth most this Forum is outstanding and I’m sure that lots of people and benefiting from it. Really great information and instruction on how to make repairs. It is appreciated.

Know to my issue at hand. My wife drives a 1996 E320 with 70K that started acting up approximately 10 days ago. She drove the car to Publix and when she was ready to leave, it did not start, but the engine would crank. After 15 minutes she finaly was able to start the car and drove it home. Next day I started the car without incident and I only made it 1/4 of a mile when it died (I tried starting it but I ended up towing the car back home). Everyday I would go out and try to started but it would only crank with the exemption of one of the time that it started but as soon as I pressed the accelerator it died, and since then I have not been able to started again. By the way the car was working great before this issue.

After reading some of the Threads and DIY's I replaced the following parts but the car still wont start:
CPS
MAF
Cooling Sensor.

The following checks I tried performing and hopefully will help understand what is the current symptoms:

Security system:
The remote seems to be working (the green mirrow light comes on when I dearmed the car, and I even can lower windows, open trunk, and open sunroof), (the red mirrow light comes on when arming the car, and I'm able to raise windows, close sunroof, etc). At this time I do not have alternating Green and red lights. The system seems to be working correctly, but if anyone has any other sugestions or knows how to dissable it completely so I'm sure that this system is not causing the problem it would be great.

Fuel Pump:

I raised the car and removed the cover for the fuel pump and it works momentarely when the key is placed on the on position, and it also works when cranking the car. I had an old A/C gage with its hose and whent a head and check the PSI at the Fuel rail with the key in the on position without cranking and it has 60 PSI and good flow.

Fuel Filter:

The fuel filter was replaced approximately 5,000 miles ago.

Relay module that mounts right side of car in front of all computers:

Two years ago I purchased the relay module but never used it and I went ahead and replaced it to make sure It was not one of the relays inside the module.

Finaly I checked all computer conections and cables/fuses (under rear seat, engine compartment, driver dash side, and fuses on the relay module and they are all ok. I removed the battery and is currently charging (it got weak after trying many times to start the car) Everything seems to be in its place and in good working order.

What would be my next step, what should I be checking next, and if I should check electrical connections can you provide the link, or specs for those readings that I will be taking? At this point I'm not sure what to do next, and any and all help will be appreciated.

Regards,

Norman

[saumil]

Need to determine if there is no spark or no fuel - spray some quick start fluid in the air intake and see if it starts - if it does, then the electrical system is o.k. Spray it at a point beyond the MAF sensor.

MAF sensor normally would not prevent car from starting, it just would run miserable.

Coolant temperature sensor is a good possibility. This one you just replace it and see if the problem goes away.

[Norman123]

Saumil,

I tried some start fluid, and the vehicle did not start, but I did have a couple of detonations (meaning it wanted to start). I been told that using start fluid with just the engine compresion can give you the impresion that trhe vehicle is cranking up, and it realy is not.

I finaly got the vehicle started after playing with the K40 relay module. Even though the module is new and I do have a spare one, I decided to manualy activate each relay to make sure that all items (i,e, horn, fuel pump, air pump, etc) were working. This procedure most have caused one of these components to start working, because as soon as I finished activating all the relays (one at a time) the vehicle crank-up after being dead for 4 days.

Does anyone have a list of items that this K40 relay controls? I know that it has 6 or seven relays inside, and the horn, fuel pump, air pump are 3 of the items. What about the othe 3 or 4 relays inside the K40.

Thanks in advance.

Norman

[saumil]

Does look like an electrical problem. My CD has electrical circuits upto 1995, so need someone else to shed some light here.

[Norman123]

Well it seems that the starting issue is solved, at least it appears that it is.

It turns out that the problem was the Camshaft Hall-effect sensor which is supplied with voltage from the relay module. The signal of the Camshaft sensor is used by the engine control module for recognition of cylinder #1, thereby providing synchronization of the injection sequence, anti-knock control, and fuel shut-off at ignition failures as well as ignition when starting. So I ended up replacing both the CPS and Camshaft Sensors.

I was able to find the problem due to an extremely great article (attached) The "Hall Effect Crankshaft Sensor"by Tech Tip, which explains in detail both sensors, to include what happens if you have a bad Camshaft sensor or CPS. Great Article. Everyone that is experiencing "Engine Turns, but it won't start" after replacing the CPS should defenetly make sure that the Camshaft sensor is working.

Thanks for your replies.