Slight missing at 40mph
Slight missing at 40mph
92 Q Traction model 130k, stock ecu/tcu, chain guides done 2 months ago, trans updated at 90k, flush 2months ago, new front brakes and oil change last week.I'm experiencing a slight missing or or uneveness upon very gentle acceleration somwhere around mid 40mph, goes away around 50. Does not seem to be there on hard acceleration. Car was in for service last week for oil change and new fornt pads and rotors turned, but the problem did not show up for several days after. The car is at normal operating temps. when it occurs, doesn't appear to be a cold start problem. My first thought was the MAF as it was just at the dealer. But the problem did not appear to be there right away. The throtlle body cleaning and additive to clean injectors also done 2 months ago. Also new fuel and air filters at that time. You guys got any ideas?
My '90Q occasionally exhibits the same behavior. Mild missing at and only at
- 38 thru 40 mph- 4 th gear with lockup- slight incline up w/ cruise or very moderate acceleration- rpms in the 1600 ish range
Virtually zero vibration at idle. New plugs, new fuel filter, new air filter, timing dead on. Currently running a can of BG44K through the tank (3/4 tank left).
I Always use chevron 93 gas.
I've assumed it's a weak injector causing a lean cylinder and pulled it down into 3 rd to get the rpms up into the power zone. My car exhibits what seems normal power at 2200+ rpm
I think I'll run the ohm meter on the injectors tonight, but if it's just a clogged injector this won't show it.
Anyone who can advise me?
- 38 thru 40 mph- 4 th gear with lockup- slight incline up w/ cruise or very moderate acceleration- rpms in the 1600 ish range
Virtually zero vibration at idle. New plugs, new fuel filter, new air filter, timing dead on. Currently running a can of BG44K through the tank (3/4 tank left).
I Always use chevron 93 gas.
I've assumed it's a weak injector causing a lean cylinder and pulled it down into 3 rd to get the rpms up into the power zone. My car exhibits what seems normal power at 2200+ rpm
I think I'll run the ohm meter on the injectors tonight, but if it's just a clogged injector this won't show it.
Anyone who can advise me?
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Q45tech
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- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Assuning you are in 4th gear [very gentle acceleration @40-45 mph] the engine may not be able to produce enough power till 50 mph to avoid lugging...[does the problem get worse with AC on vs off]......do a power balance make sure all cylinders are within +-12 rpms.............check for knock sensor problems.
Don't assume that [a single treatment of] BG44k will clean bad injectors, it is designed to keep clean ones clean.I assume the plugs were replaced with oem NGK at 120k? And the base timing is still at 15 deg BTDC.
Don't assume that [a single treatment of] BG44k will clean bad injectors, it is designed to keep clean ones clean.I assume the plugs were replaced with oem NGK at 120k? And the base timing is still at 15 deg BTDC.
Plugs were replaced at 76k for the second time, I did them at 30k even though not neccessary, so at 130k I should be 6k away from needing them, I should probably go ahead and do them anyway? 76k was also the complete tuneup or the so called 60k service which I was doing for the second time, so I suppose the timing was last checked then. this isn't a lugging problem it definitely fells as if missing. how much BG44k would you recommend before ruling that out? No difference with or without ac. is the knock sensor a normal replacement item at some point? Because I have always followed or at times done the factory schedule early. If it's not then I would for sure suspect that. Stupid question is BG44 availale through normal consumer supply and is that what it is called if you ask for it?
