'98 Maxima Stalling

[FBMax]

Hi Folks,

A search didn't give me a good answer so I'll shove my scenario out there to you all for wisdom and a little help.

The engine will idle alright, but pressing on the throttle causes it to choke out and stall. Yesterday it would rev in neutral and only stall when drive was selected (auto transmission). Today, any application of the throttle either in or out of drive causes a stall, most of the time anyway.

I have pulled the MAF connection and there's no change. Just to double check I removed the sensor and it looks clean as can be. Air filter is new, too. Pulled the fuel filter, drained it, blew through it with no problem and reinstalled.

It has been showing a SES/CEL indication for a number of months. As an aside, I had been running low octane in it during the past 3.5 years I've owned it with no obvious problem, but about 6 months ago I noticed a big increase in pinging plus got the SES so wised up and started running premium. It's improved the pinging.

I've never checked for SES codes before but I did today following instructions on the web (fwiw) and believe I got 1-2-1-15 as a code from the SES light. I'm clueless at this point to decipher that code from all the info I've been able to find.

Sorry to be long-winded but that's the picture. The car is not driveable so any direction to the problem will be appreciated.

[loystock]

It's not a good idea to ignore the CEL. A bad O2 sensor may cause your engine to run rich and eventually destroy the catalytic converter (OEM 'cat' is very expensive). You can easily get a free scan from Autozone and the likes and they will even give you a printout of the trouble codes.

The fault code you got is non-existent. A fault code has 4 digits. If you are using the built in diagnostic from the ECM, the long pulses (@ 0.6 second each) is for the FIRST 2 digits while the short pulses (@ 0.3 second each) are for the LAST 2 digits. The long and short pulses are separated by a longer pulse (@ 0.9 sec). Check this link which is available in the 'sticky' for Maxima/I30/I35 FAQ.

http://vbxmaxima.8m.com/ecu.html

You may have a vacuum leak since the engine stalls on acceleration. Check your vacuum connections (spray vacuum fitting with carburetor cleaner and listen for engine response.

You said the MAF sensor seems Ok but it could be the one giving you the problem. A failing MAF sensor can give you all sorts of problems. Use a zero-residue contact cleaner to clean the sensing element as well as connector pins. DO NOT TOUCH THE MAF SENSING ELEMENT. Apply dielectric grease on the connector. You can also use the CRC MAF Cleaner, also available from Autozone.

The problem could be due to other things so it would be better to have it scanned to obtain the fault code.

[NutriaforBreakfast]

I would try the following;1) Clean the throttle body for carbon2) Clean the idle air control valve for carbon3) See if the EGR valve is sticking closed. You willneed to use your hand to check it so dont get burned4) You might need to remove the plenum to clean outthe EGR tube (connected to plenum in the back by the firewall)

I would use carb cleaner on the rag for these but wouldnt drench any of the above with it. I would use electriccontact cleaner on the EGR valve as the FSM recommendsnot to use carb cleaner as it could hurt the rubber diaphram in it. Just use common sense and dont drench an electrical part.

[FBMax]

Thanks for those suggestions, guys. I'll get right on them.

I also found that I could finesse the throttle (in neutral) and get the revs to rise, but only to 2,500 rpm.

At that point the engine will cough repeatedly in a timed, definite pattern or cadence, if that makes sense -- cough, run, cough, run, etc.

[loystock]

Based on the info you provided, the car is in 'limp' mode due to a problem with a main sensor - MAF, Coolant Temp, TPS, Crankshaft, etc. Have it scanned ASAP.