Check Engine Light - No codes question

[OwnerCS]

I've been around the block with the 99 Maxima 5-speed over a check engine light that comes on as soon I turn on the key, but no codes are present. Car will not start at this point in time.

Has anyone seen this condition there the CEL comes on as soon as the key is turned on but no codes are indicated? There is a long list of times (fuel 30-35 lbs, fire coils, ECU replaced and reprogrammed for keys, cam and crank sensors, grounds) that have been replaced and/or validated with a working 99 I30. I think the CEL with no codes is trying to tell us something.

[maxiiiboy]

Does the starter crank? And how - fast or slow?
Also, is the red light (security light, aka NATS) next to the clock ON when you crank? If it is, there is a problem with your keys .....

[OwnerCS]

Cranks at normal speed.. New battery and alternator a few months ago. It has started and run for a couple of minutes before flooding when it stops. After a flooding episode, it takes a long time to restart it and usually only after pulling the plugs. Compression was found to be low on CYL 1 in the 100 lbs area. I haven't seen low compression cause a CEL at this point -- usually rougher than normal idle. Note it has new O2 sensors, KS and harness, and Fuel Pressure Regulator.

[maxiiiboy]

OK, so it starts, but it then floods and dies.

I would check/replace the MAF sensor. Mine went bad, the car would die when idling, and it did not throw a code. I would unplug the MAF first; if the card idles smoothly (it should, in fail-safe mode), the MAF is the problem.

[OwnerCS]

The MAF was swapped with the one in the working 99 I30. The I30 runs fine with the Maxima MAF - no change for the Maxima with the I30 MAF. Also I keep a couple of spare tested MAFs on hand. Other sensors swapped with the running I30 are the Crank position sensors and the cam position sensor. Fuel pressure spikes up to 35 then settles down to 30 a few seconds later.

[OwnerCS]

The CEL with no codes when I turn on the ignition switch is the condition that has me stumped. When I start the I30 and any other Max I've had in the past, the CEL would not be on unless a code was also present.

The other item is the car can be started for a few seconds if the fuel pump fuse is pulled. If you insert the fuse and let the pump build up pressure, then remove the fuse before trying to start it will start. Leaving the fuse installed results in it immediately flooding out. The fuel return line has been blown out to rule out any return line or dampner obstruction.

[NutriaforBreakfast]

try clamping off the part of the hose that goes to the fuel injectors,
that would be on the engine side of the fuel filter
See if the fuel pump holds pressure
I think, if not, your check valve might be bad in your fuel pump

[OwnerCS]

Thanks Nutria. Will the clamp be on the engine side of the fuel pressure gauge (between the filter and the injectors) to see if pressure remains or bleeds down from the as the result of a failing check valve?

When testing the Q a few years ago, I was able to clamp off the return line to get pressure from the pump to hold up while testing new injectors for leaks. Similar concept?

Just a passing thought it appears the injectors are pulsing way too much (all at once) or something is allowing them to pass too much fuel that is drowning the engine in fuel.

Another thought is to swap injector rails and injectors with the I30 to rule out any broken pentile caps or o-rings that could be leaking. Though the fuel pressure leak down test should rule that out without having to pull the plenum to swap the right rail.

[maxiiiboy]

The CEL with no codes when I turn on the ignition switch is the condition that has me stumped. When I start the I30 and any other Max I've had in the past, the CEL would not be on unless a code was also present.

The other item is the car can be started for a few seconds if the fuel pump fuse is pulled. If you insert the fuse and let the pump build up pressure, then remove the fuse before trying to start it will start. Leaving the fuse installed results in it immediately flooding out. The fuel return line has been blown out to rule out any return line or dampner obstruction.

Interesting. Clearly, the engine is getting too much fuel.

The ECU is controlling the amount of fuel injected by increasing/decreasing the width of the electric pulse that opens fuel injectors. Inputs from many sensors (MAF, MAP, TPS, ... ) affect this computation .... TPS comes to mind. TPS needs to be calibrated; is it possible yours got out of whack, somehow?













;

[OwnerCS]

When I had the ECU reprogrammed, I had the dealer set the TPS and IACV and run it through a consult shakedown. All they can tell me is it has low compression on 2 cylinders.

[NutriaforBreakfast]

Thanks Nutria. Will the clamp be on the engine side of the fuel pressure gauge (between the filter and the injectors) to see if pressure remains or bleeds down from the as the result of a failing check valve?

Never really have done it-saw on u tube somewhere-i think you are right

When testing the Q a few years ago, I was able to clamp off the return line to get pressure from the pump to hold up while testing new injectors for leaks. Similar concept?

YES

[maxiiiboy]

Are you able to start the car?

If you can, I would take the car to the dealer and pay him $125 (standard diagnostic fee, may vary a bit depending on your location) to diagnose your problem. With Consult II, they will be able to to pinpoint you problem in 10 minutes. Well worth the money.