Ok so i have been in fights with my car on a day to day basis. I have replaced the distributor, spark plugs, wires, maf, re-grounded the maf again, fuel filter, fuel pressure regulator and ran heat through the tank (new tank as of 9 months ago [same fuel pump]). New Timing chain tensioner and gasket. Swapped out some JWT street 2 cams for the stockers before winter started. The engine is a JDM 10:1 sr20de in a 92 SE-R.

Problem: Intermittent problems, some days it will start fine some it will take a bit of cranking, some days it will NOT start

I have found that pulling the in car fuel pump fuse is sometimes a fix for the completely not starting but if this is the case the car chugs like it has bad fuel or has the maf unplugged. While driving the car runs like a beast as long as i have very light throttle or throttle PAST 1/2 other wise it feels like i have no power what so ever.

When it starts normal it runs fine and has no problems

Usually when it cranks for a bit then starts it has low idle issues but eventually runs normal.

The idle is not that steady, when the car is cold it will stall out if i do not keep on the throttle.

Car is a MAJOR pain to start in anything below 10 deg f.

I live in northern Minnesota so the temps have been anywhere from -20 to 30's.

I have read and read and searched over hundreds of posts and have seen the fuel pump fuse thing but no one had an answer that was posted so I'm hoping to get some assistance here. (http://www.sr20forum.com/200sx-se-r/124862-cant-get-fixed.html)

My mechanic thinks it is possessed. aka maybe an ecu or fuel pressure issue (fuel pump) or something else really weird

Any help would be GREATLY appreciated,
Thanks to all in advance,

Mutmatt

bump... anyone?

is the cam timing correct? i had one off a tooth not long ago on my s4's, and the car felt the same when i put the stock cams in with everything lined up right. one other thing that i saw in my b13 was, when i regrounded my maf, it made it even worse. the engine would idle bad and die. when i took off that new ground and kept the old one, it was fine. just my two cents.

sound like your fuel pump might be dying! especially if you say it takes some cranking from time to time in order for it to turn on. when you try and give it full throttle seems like it doesn't get enough fuel but if you want to go through the diagnostic process to determine the cause i would suggest to buy a Haynes repair manual at a Autozone or parts store. I strongly suggest this manual for about $20. it will save you unnecessary replacement of parts.

It is unlikely that it is a timing problem if it runs good sometimes. If the timing were off it should run bad all the time.

It kinda sounds like the cam and crank sensor issues that the newer nissans had but it wasn't a problem on the 91-94 SE-R.

Does the ECU match the motor? If it is JDM then you don't have some of the emissions stuff that the domestic cars have right?

good luck

hope im not too late...check ur injectors if they're pulsing or not?? sound like a fuel problem...(if you do get it started...just go out on the street n full throttle it...if it ups n goes it not fuel related...) sparks n *** not should be noticable at idle...

well it went from bad to worse ever since the weather hit 50 degrees it hasn't run. We have narrowed it down to ecu and/or wiring problem. Not sure which one, the injectors get pulse at times but the temp sensor also reads -50 degrees at all times... i think my problem has turned in more of a test and test and test problem and less of an ask question one. Anyone know the difference from jdm sr20 and usdm sr20 engine harnesses

edit the ecu isn't going into the test or diagnostic mode whatever it is called

well it went from bad to worse ever since the weather hit 50 degrees it hasn't run. We have narrowed it down to ecu and/or wiring problem. Not sure which one, the injectors get pulse at times but the temp sensor also reads -50 degrees at all times... i think my problem has turned in more of a test and test and test problem and less of an ask question one. Anyone know the difference from jdm sr20 and usdm sr20 engine harnesses

edit the ecu isn't going into the test or diagnostic mode whatever it is called

It's OBDI, and I used a basic SR20 USDM ECU for emissions testing on my '91 car with a custom JWT ECU (runs a little too rich and was showing much higher NOx). My motor also is a JDM 10:1 with stock internals, but has EGR added back in, all emissions control stuff present (was a CA car, and they checked) . The borrowed ECU in the car was USDM but it still ran fine, but I did notice it didn't perform as well as the JWT tune on the upper end. But that was minor, I'm talking it didn't rock to 7500 like it usually does, it still ran well. JWT eliminates some timing issues that account for much of that.

Point is no you don't need a special ECU for that motor - I just swapped in a borrowed OEM one, the car started right up as usual, etc. More likely possibility is the ECU you have might be damaged electrically or through water damage, etc, or you have a wiring harness issue somewhere on the motor side of the wall.

Easy to eliminate the first possibility, just borrow one if you can, otherwise I think about $50 will find you a good condition used one that is compatible with the B13. Put a WTB ad if you cannot find one locally or elsewhere. I had a spare stock one but seem to have lost it somewhere, IDK what I did with the box, lol!

Also I did not do the swap personally, but am 99% sure the engine wiring harness did not change, because I can see specific things in photos before and after under the hood showing the plugs and wiring are the same as came with the car - taped a certain way, etc. Some of it is clearly OEM "packaged" and never moved or been re-routed since the car was new.

Put a FPR + gauge in-line if you think it's fuel pressure related, not normally, needed, but for diagnostic use that would be in my next steps. Also you don't mention IAAC, or whether you've done the FSM diagnostic steps there. If it's cracked, leaking, or plugged up that can cause problems. Mine had a crack in one of the stems for the lines, I replaced it with a new OEM unit since it had already been glued by the original owner and had cracked again. It was def messing up my idle. Re-check the timing, clean any hard lines and replace any suspect vacuum hoses.

But first just try a different ECU, lots cheaper than hours of labor by your mechanic chasing other ghosts.

HTH and good luck.

...Not sure which one, the injectors get pulse at times but the temp sensor also reads -50 degrees at all times...

If you didn't swap out the temp sensor for the prior OEM one, then it's reading wrong. IIRC the temp sensor on the JDM runs different V to match a JDM gauge (e.g something like deg F vs. deg C or it's just different).

Doesn't account for the poor running when warm, but could possibly make it harder to start, IDK for sure on that one.

i'm sure this thread will continue to grow... as for the iaac it is not erratic idle it is more bogging out idle like the car is flooded out. The FPR was swapped for a second one i have same issues. The lack of diagnostic light on the ecu is bothersome to me and will be looked into... just gotta see if one of the locals has a ecu i could borrow... rwd sr20de ecus are different correct?

so after sitting for some time i got the car back into my laboratory for some further troubleshooting and diagnostics... I have the car up and running but the idle is crap and the exhaust smells so much like fuel i might have well put my head in a bucket of gas. I noticed keeping the rpms up it would bounce on 2500 rpms which i'm assuming is indicitive of something ecu related being amiss. I have a 2.5 mandrel bent exhaust with headers but it looks like the stock cat was put in the mid-pipe.

My question I pose is it possible that an extremely clogged cat would cause a problem like this? And could this cause any other problems in the world of ecu/sensor readings?

Any thoughts would be greatly appreciated

In my experience cats blow out not get clogged. That much unburned gas usually lights up and the cat's guts go out the tailpipe a bit at a time.

Sounds like it is just overdosing it with fuel. Your motor is drowning and yes that rich of a mixture would explain a lot...so unless it's something like one injector, etc. I'd get another ECU, swap it and check, if nothing, then dig into the fuel delivery system. I assume you've taken apart any intakes to check for nests, etc. A blockage in the intake OR exhaust might cause the same thing, wonder if some critters made a home while it was sitting...

intake is clear, i'm going pull the cat and weld in a straight pipe because MN doesn't care on testing cars. I will look into getting a spare ecu and report back

sounds to me like a problem a crank or camshaft sensor would cause. just throwing that out there

http://www.mazdas247.com/members/Mutmatt/b13/2010-07-25%2020.47.21.jpg

http://www.mazdas247.com/members/Mutmatt/b13/2010-07-25%2020.48.00.jpg
...


****Sorry for the blurry pictures I took them in sunset lighting with my G1 phone****


Anyone have any idea if this is standard in the wiring harness that runs along the injectors? They don't look like they should be there and the fact that the metal has melted through worries me.

Also digging into the wiring there are some spots that 1 wire goes in there is a wire cramp and black sticky stuff on it wrapped in what looks like electrical tape and 2 wires come out... Is that normal or is that someones reasonably done hack job of a wiring harness.

Another quick question anyone have a lowport with the egr in place with a good picture of the drivers side of the intake mani? I have two wire clips that are just chillin there and i'm assuming that they are for the egr which has been long since blocked but still...


But to further elaborate on my problem originally I have pulled to codes from the ecu a 12 and a 13 which i have found to be maf and engine temp sensor shorted or open circuit. I tested these two sensors at the source (the sensor themselves) with my trusty multi meter. Both sensors were reading well within their correct respective ranges so it has to be something else like the wiring or ecu itself (my thoughts not someone else's) which is were the wire hunt came from.

any advice pictures things to look for anything is helpful here. thanks for listening and helping me on all these things, I don't know how people did this stuff back in the day. Forums ROCK!

Thanks,
Matt

If that's indicative of the way someone spliced in the harness then yes you have some issues. Crimp connectors per se are not unusable but not my preference. More a problem is splicing with undersized wires, creating shorts, hacking apart well insulated wires then wrapping with cheap-ass tape.

IDK exactly what view you are looking for of the EGR, I have many pics of that area of the motor, check here:

Feed Your Header (http://homepage.mac.com/stracy01/projectb13/PhotoAlbum146.html)

B13 Intake (http://homepage.mac.com/stracy01/projectb13/PhotoAlbum215.html)

B13 Intake and misc pics - More at: http://s407.photobucket.com/albums/pp154/stracy01/B13/

HTH, sounds like you're going to have to do some wire tracing and fix some of those crap connections. Could have melted from sitting against hot mani or from hot wires, hard to say...

was that fender brace meant to hold the door up due to sag? And if so was that custom made by you? Obviously it wasn't that bad to make, I ask because my doors are doing the sag and i've been looking into how to control it. I have pretty much all the necessary tools to make something like that. Have any diagrams or anything?

my car would do the same shit if it was really humid out... like foggy almost.. i'd unplug my injectors and try to start it until it wouldnt even misfire, then plug them back in and see... that's also when i go over a huge puddle without tire wells... so i think i may have just flooded it... btw thats just a side of the road fix lol...