sharmon

PLEASE, PLEASE, PLEASE take the time to read this as I am getting extremely frustrated with my car. It is a 1992 SE-R and here's the problem: it hesitates moderately when cold(especially b/w 1K and 3K) and improves drastically, but does not go entirely away, when warm. Also, the idle is at ~800, but floats up and down a little.

Here are all the things I have replaced:

-motor(with a JDM SR20DE w/5K miles)-long block
-Nissan clutch kit
-intake manifold(with all new Nissan gaskets)
-exhaust manifold(with all new Nissan gaskets)
-IAC(Idle Air Control Valve)-w/ Nissan gasket
-Plugs(NGK), wires(NGK), cap and rotor(Nissan)
-distributor(Nissan)
-knock sensor(Nissan)
-battery
-air filter(K&N)
-all vacuum and fuel lines
-fuel filter-fuel pressure is outstanding
-5W30 oil(at mechanic's suggestion)
-all four injectors and the fuel rail-all factory Nissan

Here is what has been cleaned/adjusted:

-throttle body cleaned/adjusted by a Nissan mechanic
-EGR and BPT-both cleaned in and out including the metal tube

Here are about the only things I haven't "messed with":

-The air regulator(although the mechanic said it's fine-who knows?)
-The fuel pump(although it seemed fine)

So, as you can see, I've gone over nearly everything...what else is there for me to try? Every time I go to the dealer, they charge me $85.00 just to check my car, tell me to try something(and charge me extra for that) that doesn't make a difference, and send me on my not so merry way. PLEASE HELP!!!! Thanks.

 

LittlebittaContact

have you timed the engine properly?

or is this motor electroniclly controlled?

if its possible i would put a timing light on it.

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gottabfast

They have the solution or troubleshoot on SE-R.net

sharmon

Thanks for the advice. The timing is set correctly. I have looked through SE-R.net and have tried everything on that site. One gentleman suggested regrounding my MAF unit. Is that a possible cause and is it relatively simple? Thanks for your input.

Centurion

How about the temp sensor or the
TPS.

__________________
1993 Sentra XE auto (original owner)
2005 NISMO Frontier

 

deception se-r

grounding the maf is as simple as splicing into a wire and grounding it. there are instructions on exactly how to go about it on ser.net.

PrOxLaMuS©

Or you can try the AAC Valve (Auxilary Air Control Valve)
I noticed that you replaced the IAC (Idle air control) valve, but thats whats wrong with my car, but where to find one?

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sharmon

Ok guys, since the original post date, I have changed the Air Regulator and the Throttle Position Sensor. I adjusted the TPS so that it reads .500V at idle and 4.1V at WOT. That should be perfect. I tested the MAF and found it to be at 1.7V, which is apparently right where it should be. I also regrounded the MAF to one of the primary ground lugs on the block. NOTHING CHANGED AT ALL!!! So, in addition to all the other "stuff" I've done, you can add these and the problem remains. About the only thing I haven't touched is the O2 sensor. Wouldn't I see a check engine light coming on if this part was bad??? Any other ideas before I just plain throw in the towel??? Thanks for any and all ideas.

Centurion

It may not be bad per se but it could be degraded--which wouldn't set the light off. Might as well change it, almost nothing is left to do.

__________________
1993 Sentra XE auto (original owner)
2005 NISMO Frontier

phil_minchoff

Do what any normal guy would do when his car won't cooperate- kick it! You'll feel better.
Either that, or, as I found out last month, go over ALL the vaccum tubes coming out the intake, air box, and esp. the ERG valve sensor (under the throttle body). They have tendacy to dry out and crack, which could lead to some of the problems you mentioned...

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Phil Minchoff

 

sharmon

Well, I replaced the oxygen sensor with a brand spankin' new one, as well as any other vacuum lines beneath the throttle body. Then I checked the ECU for any codes(there were none). I reset it anyway and then drove the car...SAME FRICKIN' PROBLEM, so unless someone has any last-ditch ideas for me, I am just going to live with it. The car drives 99% perfect and I have basically replaced/adjusted everything. Again, any last suggestions would be heeded. Thanks a lot for your help, guys.

nstalr01

check your evap canister. it is right below your brake booster and master cylinder if i am not mistaken. if you did replace "all" the vacum lines then you should have replaced these also but it is worth a shot just in case. as a matter of fact you can eliminate it all together by unplugging it and plugging the vac. hoses . i did this on my b13 ga and it has ran fine for over a year now.

b_dyche

I agree - check vacuum lines! My friend has a 1989 240SX with an SR20DET swap and it ran like crap - turns out he had a problem with a vacuum line - he couldn't figure out the hissing noises coming from the front of the car... I also had a similar problem with my other car (1986 Toyota Corolla) and I checked all the vacuum lines, had to replace a couple little ones and the car ran great (until Tuesday when the head gasket let go on the highway and the engine fried...)