90 Q dies...alot....

[Jester76086]

I'v put about 2k miles on my "new" Q45. With the exeption of the FPCU and the fuel pump I havent had a problem out of it. Until now. I Drive down to Austin Texas every couple of weeks (212 mile drive.) On my last trip however it started to die at stop lights. I quickly decided to go back home and on the highway the motor would die for about 1-2 second then come come back to life like nothing ever happened. I also noticed on my way back that when I floored it all was well until I hit about 5k RPM. At that point it would stutter and choke horribly until I let off the throttle.

With 92k miles on it I decided to put it in the shop. They have checked the charging system and fixed several vac leaks. They called me yesterday to give me a report. They basicly have no idea whats going on. This is a very well known shop around here and they have done several 90s Q45s.

Has anyone heard of any problems like this? Any suggestions are welcome.

NGK Iridium .40" 2k miles agoBelts done 500 miles agobattery is 6 months old and has 2k miles.

[MR. Q]

U have spark plugs, The black coil packs that go over them, fuel rail, fuel injectors, knock sensor, do you have (metal or platsic) chain guides?, dirty plenum, dirty/malfunctioning MAF, belts, pulleys. Not for sure what it could be but just some areas on a 90 Q that need to be new again.

[MR. Q]

Also the throttle body maybe fuel filter or fuel damper.

[Q45tech]

Check both CAS connectors and the purity [waveform shape] of CAS pulses.

Obviously when a mechanic or technican tells you they don't know, you have chosen the wrong shop!

[jimbyjimb]

Start with replacing the in-line fuel filter, passenger side wheel well under the hood. Then clean the MAF and it's connector, then clean both of the CAS connectors. Instructions for all should be on http://www.q45.org under tech help. Report back after driving a while and see if it is still doing this. Do you get a check engine light? Many people reccomend di-electric grease. Good luck. MAF=Mass Airflow Sensor and CAS=Crank Angle Sensor. Get a shop manual. Some people on here have links to a free downloadable service manual.

[Jester76086]

All plugs are clean. CAS pulses are clean. Havent done the plenum as of yet. Fuel filter should be ok as it only has 5k or so on it. Found a receipt in the glovebox from the shop that did the work. Theres no check engine light on. The odd thing is that it doesnt stutter then die. it just drops dead. Just got off the phone with the guys doing the work and their trying to get a motor run image off using the Conzult cable as of right now. They said this isnt the first one thats had this problem. However none of the past fixes work on this one.

[96Qowner]

That symptom is typical of a bad MAF or connector, and also low transmission fluid level, which can cause the TQ to lock up and stall the engine when braking for a stop.

[Jester76086]

MAF is possible. However its not when I brake that it dies. I can be sitting at a light for a bit then have it die. Come to think of it though, it tends to happen when I first start accelerating when the light turns more often then a dead stop...

[maxnix]

NGK Iridium .40" 2k miles ago

WRONG plugs! RTFSM and OM.

Have you checked your MAF connection? New fuel and air filter in last 12 months?