I just recently replaced
-O2 Sensor
-Battery

She was running rich and wouldn't pass smog so I changed out the parts above and she passed.

Checked spark plugs and on the very tip they are white. I think this means she is running lean.

Typical Day - I start the car after shes been sitting for about 10-12 hours. She sounds good, idles fine. Starting in first is smooth no problems, power is all there and everything. I commute 30 miles one way to work and theres lots of traffic so I'm usually driving for about an hour. I make it to work and the car seems fine. When I come home I make a stop after shes warmed up, start her up again and now when I start off the clutch/flywheel Chatters like a *****. It chirps the tires sometimes. (This doesn't happen when the engine is cold or somewhat warm). Then when I go to hit the gas, maybe half throttle or full (doesn't matter) I get this delay then it takes off then after about 3k to 3.5k I have no power. Its the equivelant to 1/8 throttle and it should be WOT. This happens in every gear except 5th it seems, This can happen either until i get home or sometimes the car "wakes up" after like 30 mins. Then I will have full power again.

It's very wierd and TBH it's driving me nuts!

Also the car bucks around when I get on and off the throttle. Motor/Tranny bounce like 2-3 times when I get on and off the throttle. I just replaced motor mounts (nismo). It was really smooth at first then it started bucking. I'm not sure if these 2 issues are related.


Another issue that MIGHT be related. I'm running a 1000 watt rockford amp with a 2 farad cap. Randomly the power will be cut from both the cap and the amp. My driver side window wont work and thats when my car is slow.

I sat down and thought about this with my father, we both have minimal experience with cars. We seem to think it's either the fuel filter, fuel pump, or possibly the MAF. The amp issue I have NO IDEA, All the grounds seem straight.

Let me know what you guys think.. Sorry about the story. THANKS!

 

ghost town forum

 

i think you might be drawing too much power so the alt cant keep up but doesnt seem likely. wouldnt hurt to replace fuel filter tho. its only ten bucks... id give that a shot first.

 

I installed a z32 filter.. Seems to working pretty well, a lot smoother. Only drive for 1.5 days so I'll keep ya posted

 

Ok, now I am REALLY starting to get frustrated......

I've replaced the following

Battery
Grounds
O2 sensor
Intake filter (Cold air Intake)
Cleaned the MAF
Fuel Filter (z32)
Changed out with another ECU
cleaned DIST Cap
Checked spark from ignition

All seems good


This is my theory... I have an audio system.. 1 amp with 2 subs. I have a CAP inline from the battery to the amp. I'll have the Stereo off or on (doesn't matter) and the CAP will start to beep, indicating it has lost power. Then it turns off along with the amp (if its on) Sometimes it will kick right back on and sometimes it stays off for a while. It always comes back full power though.

My battery shows 14 V when first started. Roughly 13.5 after an hour of driving. I show the same at the CAP when it is working. Being as this is random i dont have the oppurtunity to test the cap while its beeping... Because the CAP only looses power while I am moving. I did notice it once while it was beeping the Voltage readout read 8V.. Which is not good.

MY huge question that I am begging you guys to think about. How in the world can this be happening? I sanded down the paint on body for the amps ground. NO PAINT AT ALL. I used the Seatbelt bolt and a 2 ft ground.

My o2 sensor is about 4 inches away from the exhaust port on the block is this ok? Its on Pace Setter header (I know they suck i bought the car with it.) I also have an injen cold air intake which is a foot off the ground and a straight through borla exhaust. Theres only 1 o2 sensor correct?

I think my performance issue and the amp issue are related somehow. They don't happen at the same time though. I don't want to bring it somewhere because of the randomness of the issues. Thanks for reading.

 

Ok, I took out the CAP, Took out the AMP and i replaced the spark plugs and wires.... She is still running slow.. I'm going the replace to DIST Cap next.

One thing i noticed.. as my Cold Air Intake is on top of the radiator, the pipe gets really hot. Could hot intake temps cause me to lose that much power? Its been really hot out and I've noticed it more with the heat. What do you guys think?

 

well i noticed during summer the car does run a bit slower but not too drastically slow. id put back in the stock intake and see what happens before dropping in more cash. you dont want to throw money at it and hope the problem will go away. what year is the car btw?

 

It's a 91 and i dont have a stock intake to throw back on there.. i bought the car wit the intake on it.

 

hows the idle? is the cel on? how does the car drive with a/c off?

 

Idle is smooooth. The engine is s14 but it has s13 cams

No A/C at all.. no compressor. No CEL. it has something to do with heat... so frustrated..

 

your problems makes me frustrated too, lol.

check voltage/resistance from maf specs in the fsm

and fuel pressure test, should be about 42 psi at idle and 34 at 2 grand rpm iirc

 

I looked in FSM but did not see the voltage/resistance specs nor where to place leads. thx

 

supply voltage 11-14
output voltage 0.8-1.2

*when car is warmed up and under no load

looks like you have to poke thru the wires

oh yeah, its 43 psi at idle vacuum hose connected and 34 psi hose disconnected

fsm suggestioned order of diagnosing:

1)fuel pressure check
2)check for any vacuum leaks along the air intake