Few Questions about recently purchased '94 Z34

[red_z34]

Hey guys, i just recently purchased a 1994 Chevrolet Lumina Z34, 2-door, auto to replace my beloved 1994 Pontiac Sunbird Le, 2-door, auto, 3.1. My dad used to own a 1992 Lumina Euro-sport 4-door 3.4l so we are famliar with these engines and their common problems,, however i got a very good deal on this car and it is spotless.

 

The car itself has 229,000Kms on it and the motor has around 190,000KM (heard this from previous owner).

 

I have a few questions.....

 

I read that somewhere that free-revving was limited to 3000RPM, but i can easily free rev mine past 4000RPM, which i rarely do, but thought i would ask if maybe the car was chipped or something to allow this??

 

Also, im not sure if all the 3.4 DOHC are like this or not, but from a dead stop if i put it WOT, it will not even let out the littlest chirp or squack from the tires, and is quite doggy until the powerband kicks in at around 4000RPM. Is this normal??? Because on my 3.1L i could squeel the tires on request.

 

Another thing, my check engine light will come on while driving, not while idling. Then it will flick off, then a while down the road it will kick on again. Previous owner figured it was a vacum leak? I am not sure. I tried to pull the engine code using the paperclip but when i turned the ignition on the 'service engine soon' light did not flash at all and just stayed solid. Any ideas??

 

Last concern, is that on cold starts (from sitting over nite) the engine cranks for quite a while before starting, but after its been started it will start at the touch of the key. Is it possible the engine is getting too much fuel by cause of leaking fuel injectors (or the like) and that is also contributing to bad bottom end because its having a tough time burning all that fuel until the RPMs are raised??

 

Thanks guys any help would be greatly appriciated....

 

-Neil

[Psych0matt]

i believe the rev limit on it is 4,500 (id have to double check)

 

3.4's don't have a very good bottom end, but most of the power is around 2500 or so and you should definitely feel it start pulling if you leave it at WOT.

 

check engine light, not sure, could be a number of things, and the reason the paper clip thing doesnt work, is because it's a 94. I have a 94, its annoying that that trick doesnt work, but 94 and 95 were the stupid OBD1.5.

 

the cold start thing is fairly normal. how long does it take to get started, a few turns over? or like more than 5?

[Regal_GS_1989]

Mine will not free rev above 3000. I have seen some that go higher than that, so i wouldn't be too concerned. As for the car being sluggish off the line, could be a few different things. Possibly a top engine clean would correct the problem.

[Crazy K]

do a tune up.

 

two things I am aware of that cause the check engine light to light while the car in going and sometimes shut off too are an out of spec oxygen sensor, and a bad egr. but there could be more.

 

do an oil change, put in ac delco plugs, fresh filters, fuel injector cleaner.... see if that improves it.

[red_z34]

thanks for the quick reply's. Forgot to mention that the first thing i did since i bought it were 6 brand new AC Delco plugs, fresh oil change (10W30 High mileage Quaker State), new fuel filter, and ran throttle body cleaner through the TB while running.

 

Whats a top engine clean?

 

Most of the time it will start within a few engine cranks but once or twice im sure it took more than 5 cranks too start.

 

Where is the oxygen sensor located? I have been meaning to replace that. Also i will clean the egr? I will run fuel injector cleaner in it as well.

 

Is my theory of the engine flooding itself out of the question? Such as leaky injector or bad fuel pressure regulator? Are there any ways to check the correct operation?

 

It still puzzles me how it wont spin the tires off the line...an engine with so much HP/TRQ i would think would have lots of off the line power...not that i want to be spinning them but maybe it (3.4) dosnt make much power in the Low RPM's. And at WOT im pretty sure it didnt feel like any power was being made until 4000RPM (then the tach would go from 4000-redline in an instant with tons of power)....

 

I will double check again it just seems like i dont have any LOW RPM power.

 

Thanks again guys this is greatly apprciated.

[Psych0matt]

where are you from?

[97loudcut]

Seafoam the car.

 

Go out and buy a can of Seafoam and pour half the can into a cup and such it up thorugh your intake via the brake booster hose.

 

Works wonders and smokes for the dickens.

 

http://www.w-body.com/forum/index.php/topic,50459.0.html

[red_z34]

im from Ontario and havnt been able to find Sea-foam anywhere..........

[Stevo]

Yeah I'm on the EastCoast and never heard of it either.

 

I searched.

 

 

 

SEA FOAM can be found in many of the following auto parts stores:

 

ABC Auto Parts

Advance Auto Parts

Auto Value

Bumper to Bumper

CARQUEST Auto Parts

Midway Auto Supply

NAPA Auto Parts

O'Reilly Auto Parts

Parts Plus

PEPBOYS Auto

Pronto Auto Parts

[CSI_MuNkY]

im from Ontario and havnt been able to find Sea-foam anywhere..........

 

Where abouts in Ontario are you located?

 

If the idle is an EGR or an O2 sensor, I would suggest taking it to a shop and getting them to scan it. Mine was runnig a code for the longest time, turned out to be an unplugged O2 sensor from when I got it repaired last. It was fine when the engine was cold, but as soon as it came on it lit up the idiot light. I priced out the EGR when all that happened and it was $400+ and thats with my fathers GM discount. Might be worth it for you to get it scanned and make sure your fixing the correct part.

 

Jamie

[BIGBULS]

LQ1's don't make shit for low rpm grunt..............it's the nature of the beast.

 

Basically, to spin the tires, run the engine up against the torque convertor to 2K or so, and pop off the brake while going WOT............it should spin the tires to 2800-3K rpm, which is about a perfect launch.

 

[red_z34]

well i managed to find sea-foam from a buddy of mines freind who runs a Import Car Garage or something along those lines. When i get it i will run it through the car.

 

Any other good maintenance/performance tips i can do for this car?? Im thinking of doing the fender cold air intake mod..Is it worth it?

 

Also... i just replaced both mufflers with 2 1/4" Magnaflows.

[Z34-5speed]

Magnaflows kick ass!!! I don't know if Ben can make a chip for OBD1.5. I would definately go with the fenderwell intake.An FFP Motormount would also be good. Under drive pullys would also be nice if you can do them yourself. Before i got my 92 5speed Z34 i used to have a 93 Z34 auto. It would easily spin the tires. The only thing i can think that may be wrong is bad timing, maybe. I would definately seafoam the car, change the o2 sensor and replace/clean the egr.

 

Here is a link to FFP...

http://www.fastfwdperformance.com/

 

Kyle

[GutlessSupreme]

There is no chip available for OBD 1.5.

[CSI_MuNkY]

Ben over on 60degree has been working on a chip for some time. Its been nearly 2 months since I last heard anything on the 95 chip. Last update I got was that he was messing with shift points but to no avail.

Not sure if he ever comes on here, so I will msg him and see whats goin on with it these days.

I've heard (I can't remember where I heard it) that the 95 OBD 1.5 can't be chipped, i can't remember what the reasoning was (if any was given)

I'll update when I hear back from Ben...

 

Jamie

 

*edit*

wow hes quick.... still no progress, hes having issues getting the car to run right to do any tuning