sluggish Q

[joe dirt]

just picked up a 91 Q45a, The car had a recent head gasket/valve job some new injectors, chain guides...ect. few guestions, when accelerating from stand still it seems to start in too high of a gear (takes a while to build up steam) also when rolling if you stomp it no down shift unless going very slow. if i stand on it at sixty ,it should pull to the moon but at about eighty it kinda flattens out then it will start pulling again. the previos owner said it never did down shift and go, but he's not a lead foot, just when he pulled out in traffic it didn't down shift and rip. so i don't think it has to do with the engine work but i don't know?? about the engine work. there is a vibration in neutral when i ease it up to about 2500 rpm . these things do not seem right for this car???.

[Q451990]

The 91Q came from the factory with 2nd gear start. Vibrations could be exhaust hangers, transmission mount, engine mounts, dirty plenum or throttle body, dirty injectors (the ones that weren't replaced)... Use the search feature to look for common problems and also through the Infiniti Articles. The 93TCU or a JWT TCU will be a great upgrade for performance and transmission health since it adds first gear start. Check knock sensors as well... they can cause power issues.

Welcome to NICO!!

Heath

[greg_atlanta]

Transmission should downshift to 1st under 25 mph and will downshift to 2nd at 70 mph, but there is a big dead spot in between there.... just the way the car is geared.

Not a very perky car around town, but rocks on the interstate!! :rockon

[elwesso]

Yep..... A not clean plenum and bad knock sensors will KILL off the line acceleration!!!

[nuQ]

at your next redlight, try manually shifting into first, when you see green...mash the accelerator! when you 6500 rpm's pop to your left into second..................etc. after this if you're still not "feelin'" it, better start looking for the other usual causes. i have a 90Q, and speaking from experience, anything under 60 mph (performance wise), has to be manually extracted (unless you get the tcu upgrade). not so bad,,,gives you that whole "sleeping giant" kinda thing!!!!!LOL jeff

[joe dirt]

thanks for the responses. which tcu is prefered 93 or jwt and what can i expect to pay ? i haven't pulled out the manual to see where it's located yet, is it hard to get to? also as for the vibration, it looks like there are some cracks on the plastic hub part of the fan, is there a history of trouble with them? I also have a very slow leak around the active pump area,the previous owner said he tightened all the fittings he could find,but it still leaks. very slow leak will not leave any on the driveway ,it's just wet and a little fluid has to be added every so often. thanks again

[elwesso]

TCU is on the driver side kick panel...... Right next to the E brake...... Theres a little nut on the firewall side that will allow you to then pull off the cover.......

The fans will crack and deform eventually......