so im back once again to discuss my hesitation problem im getting with my LS. my LS is great except for this stupid fuel problem told to me by my friends uncle who is a mechanic. ive replaced a fuel filter already and this still occurs. what basically happens is when i accelerate, the car feels like its receiving too little fuel and it stutters instead of being a smooth curve to the next gear, when its about to shift, the car vibrates and shakes until it finally shifts and then its smooth until the next shift point. what is worse is that when it is cold, this gets worse and i have to warm up my car for a extended period of time (5 mins, bad for atmosphere and gas) and IF i dont warm it up, the car stutters and vibrates even more violently. for example, today i was leaving a friends house and he lives like 2 minutes away from the highway, so once i pull from my spot, i automatically knew that i shouldnt have left so early and shouldve let it warmed up because EVEN IF my foot isnt on the accelerator, the car bogs as if it was misfiring or something and i was so scared something was going to break i almost wanted to put my hazards on (i live like 5 minutes away from his house) but i continued driving on the highway and once it warmed up, it went away(but hesitation still there if i really step on it). good thing this was at 11:20ishpm EST and barely any traffic on the road so i was able to make a slow acceleration from 20-60 (took about 1 minute) but this problem is getting on my nerves and the mechanic recommended id do a fuel pressure test but i dont know what to do right now. so im trying to get some more info from you friendly CL guys. thanks for reading this long passage.

 

From what you're describing I had a VERY similar problem with my 91 LS400. Is yours throwing any codes? I replaced the plugs..then wires..and nothing changed. So I took some advice from a good mechanic and had my injectors pulled out , cleaned, and soaked for about an entire day, it was pretty spendy (maybe around $600? can't really remember) but it cured up the problem 100% and I never had a problem again!!!! I would totally recommend doing it!

 

no codes relating to this problem, just a trac problem(problem in engine control system?). hmm injectors? any DIY to remove/clean them?(gonna check lexls anyways).

 

Yeah my TRAC light was coming on too I believe... I wouldn't want to tackle injectors unless you have a shop and a LOT of experience it sounded like a huge project, took all day. Pretty labor intensive thats why it was so much... as for cleaning them after you get them out i'd have no idea what to use, I'd rather let someone else do it so i can blame them if it something fails!!! hahaha

 

well im kinda the DIY type of person and learning to become a mechanic so learning and fixing is better for me.

 

Take it to stealer and get it diagnosed first.

 

haha yea i would take it to a dealer. you dont wanna freak up your injectors. than have to make 200 each for new ones ahhhhhh. run some octane booster and fuel injector cleaner into that bad boi. that could possible help too. only spendin 20 bucks to see if ti works

 

Before doing something like removing your fuel injectors, which I'm doubtful will fix anything, I would check your fuel pressure just as your mechanic suggested. Also, what ignition components have been replaced on your car and what is it's current mileage? If you want to clean your injectors without removing them you can do some good by adding something like BG44k to your tank, carefully noting BG's dilution ration noted on the can. However, I am doubtful that the cause is your injectors since they are less likely to have issues than other components upstream, like the fuel pressure regulator or the ignition components. One last question that may be of use: How is your car at starting? Does it fire right up? How many times does engine crank over before it turns over when you start it in the morning? Fuel pressure issues will also often cause issues starting, especially in the morning when you first start the car for the day.

 

1. spark plugs have been changed, meaning to change my plug wires, rotors, and cap soon.
2. 162k miles
3. sometimes it starts up fast sometimes it takes about 3-5 cranks.
also when im starting in the morning, i get a strong gasoline smell but this happened after i changed my fuel filter, before it had no smell but now it does.

thanks for responses but how much was it to diagnose your car at dealer? 80?

 

Yeah around that, but they also tend to want to replace an entire system instead of pinpointing exact part. (Don't want to take the time)

 

I had EXACT Same Problem when I bought my 93 ls,having a repair shop I had acess to to a used TPS, MAF fuel reg. ETC It was TAAA DAAA the ECM even though it set NO codes... $250 Rebuild and the ghost went BYE BYE

 

engine control module??? i am getting a trac code for the ECM.....gonna try some fuel injector cleaner first then ill run a fuel pressure test.

 

Sounds like your fuel pump is going.

 

ur the 2nd person to tell me that...gonna try the fuel injector cleaner and is it possible to check whether or not ur fuel pump is going?