no power out the hole

Jonnysj30 · Post by **Jonnysj30** » Sat Apr 17, 2010 8:46 am

i have a 93 j30t and it has a misfire and no power out the hole // engine runs fine cold but when warm. car shakes while at a light.also tappet noise. ive replaced spark plugs fuel filter and nothing changed

Jonnysj30 · Post by **Jonnysj30** » Sat Apr 17, 2010 8:47 am

i have a 93 j30t and it has a misfire and no power out the hole // engine runs fine cold but when warm. car shakes while at a light.also tappet noise. ive replaced spark plugs fuel filter and nothing changed

Post by **yodawill2000** » Sat Apr 17, 2010 9:01 am

Check the ecu codes for a knock sensor issue.
It wont trigger a check engine light but will retard the timing.
If it has a crack it will act up after the engine is warmed up.

Post by **SteveTheTech** » Sat Apr 17, 2010 5:28 pm

I lol'd when I first read the title of your thread, thinking you were actually racing a J. Great attention grabber.
Welcome to Nico.

It sounds like timing or fuel to me.

The easiest thing to check would be fuel pressure if you have a gauge. The pressure might be right but the flow might be low. There might also be a vacuum leak causing the car to run lean...to lean for the computer to fix.

In a case like this start with what seems most realistic of the four elements needed for combustion.
Fuel,Air,Spark,Timing.

-MOD EDIT- Hey guys I merged the threads about the same issue.

Post by **driverdriver** » Sat Apr 17, 2010 6:52 pm

Steve-Thanks for merging he thread. I'm still in the learning process with the mod tools for this new forum software.

Post by **#1 Sailor Scout** » Sat Apr 17, 2010 10:09 pm

One thing to try is to use Premium fuel only. If you use any grade lower than that for an extended period of time, that's when things can go wrong.

I say try using 91-93 octane + octane booster from your local auto parts store & report back.

Jonnysj30 · Post by **Jonnysj30** » Sun Apr 18, 2010 8:59 am

i use only premium gas and valvaline oil with lucas additives// just cleaned throttle boddies but didnt help where do i get the redline stuff? // do i have to un bolt ucu to read codes because i didnt find switch or led light ?

Post by **driverdriver** » Sun Apr 18, 2010 10:01 am

Light is on top. Yes you have to unbolt and turn the screw to read the light.

Jonnysj30 · Post by **Jonnysj30** » Sun Apr 18, 2010 2:25 pm

just pulled ecu and got a code 34 knock sensor,,,,,,,what gaskets are needed to do the job and what shoul be replaced when i do it?

Post by **95J30tBGGUY** » Wed Apr 21, 2010 9:33 am

I pulled the same code from mine. With me the problem is after the engine reached its normal operating temperature is and I shut it down (ex. go to walmart for 10 to 15 min. ) and when I start the engine it shakes a lot . I race it for 5 sec at 2000 rpm then everything seems ok. I don't know if thats form the knock sensor or something else

Post by **yodawill2000** » Wed Apr 21, 2010 9:51 am

If the timing retards after the engine warms up your Knock sensor may have a crack in it.
It will open up when hot.
Has the engine overheated recently ??
That will crack a knock sensor by design.

sconus · Post by **sconus** » Wed Apr 21, 2010 10:10 pm

Great post! I recently bought a 94 j30 from my brother, with 174k. Last week it started to struggle on my way home from work, about 10 mins into the drive, and i noticed at stop lights the engine would start struggling and the dash lights would flash on the bottom of the cluster, kind of like the car was on the verge of turning off. Im not sure what it is, Ive been using premium gas, just got an oil change, I know the fuel pump was changed about 6 months ago, I also used a lucas additive before i last filled the tank and the air filter is looks clean.
This only happens after the car warms up, I wonder if its the knock sensor... I will have the local mechanic to pull up the codes for me so I can look it up.
Can anybody else think of what else it could be?
By the way I love this car. She needs some work, it wasnt running when I got it ($300) a month ago but I plan on bringing her back to her beautiful help! I'm glad I found you guys. =)

Post by **GerryO** » Thu Apr 22, 2010 9:59 pm

One more thing to consider and I'm quoting ©Maciej Nowakowski 2000:

PCV-Valves:
The Positive Crankcase Ventilation valves are located under the plenum on its right and left side. Faulty PCVs can cause crank case air to be sucked in to the plenum at times when it's not supposed to. They can also get stuck closed so that excessive pressure is built up inside the crankcase causing the engine oil to leak through the rear main seal and sometimes the oil dipstick to pop out.

There is also one more symptom that happened to me. The spring inside the PCVs got weak so they opened while braking and that caused the engine to stall after a fairly hard braking. I would recommend everyone with an older Z to replace them. They cost~$3.4 so it's not a big deal (PN 11810-40P00).

Be sure to get new rubber hoses since the old ones are probably hard as a rock and you have to cut them. The part numbers are 11826-30P11 for the left one and 11826-30P01 for the right one (~$23 total).

Remove the battery while replacing the PCV on passenger side.
Do not over torque them when installing, as you can break the plenum!!

Post by **SteveTheTech** » Fri Apr 23, 2010 6:25 pm

sconus wrote:Last week it started to struggle on my way home from work,
This only happens after the car warms up,

Welcome :1
Check your Idle Air Control module This is located on the drivers side rear of the intake plenum. I would bet you there is an abundance of carbon deposited on the holes that allow the system to correctly regulate the airflow at idle. Remove and clean that and drive it like you stole it (without abusing it, there is a difference) you want to get the engine up to operating temperature and get the RPMs up there to help coax some of the sludge out of the top end.

The reason the IAC might be suspect is that when the engine is cold fast idle is basically wide open while precision idle control in closed loop requires much more finite movement of the linear solenoid. Carbon impedes operation of many normally operating IAC valves causing all kinds of idle issues, depending on where and how much carbon and sludge there is.

sconus · Post by **sconus** » Wed Apr 28, 2010 7:01 pm

Hi guys, Steve are you talking about this little guy?
95-j30-idle-air-control-valve-t485132.html
I should take out the 4 bolts, and two hoses i presume and clean it out?

I noticed this J30 eats up way more gas then i think it should and looses power after warming up.
Could this mean?
Maybe replace the pcv valves and clean out the hoses?
I also plan on cleaning out the throttle bodies.
In conclusion...
clean throttlebodies,
replace pcv valves / inspect and clean hoses
clean idle air control module.

After 174k miles, this baby needs some tlc.

Will keep you guys updated on my tune-up part 2

Post by RQ » Fri Apr 30, 2010 3:42 pm

I'm going to jump in on this too. Mine has started having no power out of the hole and then catches up in a few moments. I Haven't checked codes yet and daughter has been running regular gas so I'm going to start with some octane booster and injector cleaner.
My tools are not here so can't check fuel pressure either.
Could the gas cap vent have anything to do with this problem?

Post by **SteveTheTech** » Sat May 01, 2010 6:15 am

sconus wrote:Hi guys, Steve are you talking about this little guy?
95-j30-idle-air-control-valve-t485132.html
I should take out the 4 bolts, and two hoses i presume and clean it out?

Those are indeed some glorified iac pics in the link posted. The majority of our cars will not look that pretty behind the intake plenum.
Having done a few of these over the years I have to suggest a few things.
Be very careful not to loose any of the securing bolts.
3 is not good enough and unless you have a drawer full of exact bolts you might have a wicked vacuum leak when you start it up.

There are two connectors that use the really old school connectors that require special attention in order to keep them intact.
I suggest using a small sharp hook or pocket screwdriver to unlock and start to remove. Using a small pair of needle nose pliers or a hemostat secure that incredibly important metal clip. There is a trick to these.
Pull the connector half way off (past the tabs on the side) and put the securing ring back on before going any farther (that makes reassembly much much easier)

Before you try this put your hand back there and touch all four bolts...if you do not have a set or sockets and extensions that will adequately get these off don't start.

The Js tend to run kind of cold and have a long complex intake setup that ,when working correctly adds EGR fumes into the bottom of the intake. This is a recipe for sludge of biblical proportions. There are ways to give these cars the correct tlc, but it is time consuming and kind of pricey.

sconus · Post by **sconus** » Sun May 16, 2010 8:31 am

OK guys sorry for the long wait! This weekend I finally fixed my stalling after warm up issues.
What I did was start from the begging, I took out the whole air intake setup, box, MAF, Plastic intake that goes into both throttleboddies, and the throttle boddies. I cleaned everything properly with the right stuff, put it back together and for the last 2 days she's been idleing great with no stalling issues!
But I still notice a loss of power after she warms up, not that I'm one for burning rubber, but I love the power she has in the morning for the first 2 mins.
I guess I have the bite the bullet and get into the IACV and take it apart and clean it. I was going to do that this weekend, but It took me almost 3 hours to do what I had mentioned above. Didn't have the patience for all that.
Thats what I will take care of next weekend.
ONce again, thanks for all your help so far folks!