Dear Roy,
We have a 1997 Nissan Altima with a 2.4L engine with automatic transmission that came in on a hook: It cranks but won?t start. The owner replaced the coil, but it did not fix the problem. My scan tool found no codes. Here is a list of what I?ve done:
1. The spark is good but seemed a little weak, so I charged the battery and tested again. The spark appears to get better. I also found that without the cap on, spark at the coil was a lot stronger. I found a corroded rotor and replaced it. After replacing the fuel-fouled plugs, the spark was much better.
2. I checked the 1 degree signal at the distributor. The signal is good.
3. I checked the 180 degree signal, and all were OK.
4. I checked the injectors; all were OK.
5. I ran a compression test: 95, 105, 95, 95. It might be a little low because of the fuel in the cylinders, but should be enough to run.
Fuel pressure is very good. Crankshaft position sensor, timing and throttle position sensor are good.
Now, when we pull a plug wire and ground it to the side of the tube, we get a very good spark. We dropped the exhaust to rule out any restrictions, but it did not help. Now we have spark, fuel, compression, and the vehicle is in time. This vehicle should run but will not. Any help would be great.
Todd Weiss, Owner
NTW Performance, Montgomery, AL
Dear Mr. Weiss,
Your right, this engine should be running. However, let?s go over some areas you may have overlooked.
First, did you sample the fuel and check its quality? Does the engine start if you inject some propane in the intake? If it does, check the mass airflow voltage.
With the KOEO, you should see 0.19V to 0.25V. If the voltage is incorrect, the engine may not start. Did you check the distributor plate for oil contamination? This was a common problem with these engines. Is the distributor properly timed?
Last, I would check cam timing. The low compression readings could be the result of fuel wash, but 90 psi of compression on an engine that typically puts out 150 psi would make this check worth the effort.STUMPED?Let Roy take a crack at your problem. Our "Troubleshooting" column is for automotive service professionals. If you have a particularly perplexing problem in your bay, Contributing Editor Roy Ripple may be able to help. We need to know the vehicle year, make, model, engine, transmission, accessories and VIN. Include your name, address and phone number so we can contact you. To send an electronic message to Roy,click here.
