v30magna

Bought a broke down s13 Fastback from the local wrecker for $500 with title. Guy said previous owner though it was the fuel pump. car started on starter fluid but ran rough. diagnostics showed the fuel pump was bad, so i cleaned out the gas tank (it had a lot of old fuel varnish) and replaced the fuel pump. The plug wires all broke when I removed them, so I replaced all the plug wires and plugs.

Started it up. Car ran rough, but fired right up. I removed the distributor cap to clean it and accidentally broke it while it was on the bench. I replaced it with a cheapo from O'rielys. had to move the screws inward a little, and file a recess for the bottom vent for it to fit, but the car fired right back up, but it still ran rough. I checked for fire on all plugs (pulled the plug and held it to the vc while wife turned the key). All fire.

pulled plug wires one at a time to see which cylinders weren't firing. car was only running on cylinders 2 and 4, but it still ran and started up easy.

checked injector resistance. 1 and 3 were out of spec from 2 and 4. So I ordered a couple injectors on friday, sept 12th. Installed them today (new ones matched 2 and 4 spec. engine rotates, but will not start! It ran on 2 cylinders before, now none!

Pulled plugs, they were wet, all of them. let the gas dry with plugs out for a few minutes. Checked compression, 155, 155, 160, 162 ~cold~. Increasing numbers probably due to more complete drying of the unburnt fuel.

pulled fuel pump fuse from engine bay, tried to start again with just starter fluid. Nothing but one or two beats that hit from cylinder 3 with the starter fluid (i pulled the plugs again and 3 was dryer than the others)

So I have spark, compression, and fuel, ~no run condition~. Any ideas?

kruked

Check the ECU for codes? Check ECU board for burnt traces? Check all grounds?

I would get a different cap and a new rotor, see what happens.

__________________
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v30magna

swapped out all the gas for fresh 91 octane non-ethanol, no help...

looked into cylinder 1 while the wife cranked the engine. injector seems to be fogging, not just dumping, so i don't suspect it is stuck.


Gonna run the codes, check the ecu I guess. (how do you run codes on this car?)

Would valve or ignition timing possibly be the fault?

I'll check the ign timing if I get time tomorrow. how the heck would I check the valve timing?

Gotta work and then I'm trying to buy some random exterior stuff for the car from a local guy.

Frank_Jaeger

I would check into this exactly. Don't forget grounds.

v30magna

OK, I will try, but it is counter intuitive...

I laid all 4 plugs on the vc and turned the starter. all 4 plugs are sparking.

I'm sure it is something stupid and simple. I'm probably just misinterpreting the results of one of the tests I have already performed. That's usually the case. I fix vintage motorcycles, so I chase improbable, seemingly unsolvable issues like this every damn day.

Makes me appreciate my Mazdas that much more. a set of plug wires and a $30 HEI ignitor mod will resurrect most KLDE. Easy Peasy Japanesy

blkvrtswp

You are missing a component here. For an engine to run, you must have:

spark
compression
fuel
AND PROPER TIMING.

I would concentrate on dist cap and timing. Good luck!

v30magna

got the right distributor cap now but no run yet.

Being new to Nissan, I learned today that there is a hitachi disty and a mitsubishi disty. I have a Mitsubishi. Be sure to specify at the parts house or you only get a 50/50 chance of getting the right part.

I will dive into timing when work allows. I'll try to follow some info I found using the search.

Was it necessary for Nissan to put the head gasket across the middle of the timing cover? Another thumbs down. Definitely not built to be repaired.

From what I can tell, everything but the interior was meant to be serviced with the car on a lift and the engine and trans out of the car.

Thx so far guys.

v30magna

how about these jack points? Don't know how to confirm it, but I'm pretty sure more people have been crushed under the s13 chassis than any other car in history.

v30magna

I checked the valve timing and ign timing. looks ok. I took pictures, but the site won't let me post them.

ran the codes. got a code 13, coolant temp circuit. r

eset the codes and tried to start it some more. ran codes again, got 55, all good.

Checked pulses at injectors harness (where they connect to the injector), all were pulsing the same except connector 3. it didn't pulse.


nothing hitting though...

blkvrtswp

I have seen many engines flooded after having no-start issues. Between having the timing off (especially if the distributor was pulled out) and then being flooded for whatever reason, it can be a frustrating task to get everything dry and the timing to a spot where the engine will run without flooding the cyls again.

If you pulled the distributor out ever, I would recommend assuming you got it wrong and doing it all over from step 1 in the FSM. You are using the exact FSM procedure, right?

1 injector down would not stop the engine from starting and running, but it is a place to start fixing.

Nissan's and 240's are probably the easiest cars to work on I have ever owned. 20+ year old bolts don't <always> snap off (cough cough GM/Buick), and there is plenty of room in the engine bay to work vs FWD cars.

v30magna

I was doing some searching. Appearently there is a plague that takes out s13s. People post with a no run condition and are never able to fix their cars. I looked at about 20 cases last night and no one has figured it out.

Anyone ever got any leads?

I came into this project with a lot of respect for the legends of Nismo, but now regard nissan as inferiority quality, abt the same as most people feel abt Ford Probes, and will advise all my customers not to buy them.

If this car runs again, it's not because the engineers built a good car, it's because I'm the mechanic. I'm gonna fix it if I can and let you guys know what issue is. Stay posted.

v30magna

I didn't pull the disty. Just the vc to check timing marks, which looked to be in the correct locations according to images I found up here.

I have always owned Ford and Mazda cars and assumed I had "hard to work on, inferior vehicles" because everyone else always told me so. I am here to tell you now that those are lies. My 93 Mazda Mx6 exceeds this car in every aspect I can percieve. You just can't drift it.

v30magna

I have had 3 10mm head bolts snap off so far. I guess GM built this little 240 of mine, right?

v30magna

Disconnected the maf, no start. Disconnected the fuel pump fuse and Disconnected the tps and started cranking the car to check the timing. Set the timing to 20 like the book says, but while cranking. So the darn thing tried to start. Hit the switch again and it started up. But while running the timing is out to like 35 right now. It still sounded like it was missing a little (I suspect the 3 since it wasn't pulsing during previous test.), but was running pretty smooth. Installed the fuel pump fuse. Reconnected the tps and maf. Started running rougher, had to give it some throttle to keep it going. Disconnected the maf and tps but idle still declined. Finally started throwing coal and I let off the gas and it died. Pulled the plugs and they are all 4 fuzzy black. Running rich.

I alternated pulling starting, and replacing the fuel pump fuse, and it seems it is easier to start with the fuse removed, so I feel it's over fueling its self.

Gonna open the air box again to be sure there isn't obstruction in the fresh air intake tubes.
gonna try to get it running again and put the timing on 20 while running and see what happens. Gotta figure out what's up with #3 too.

I think I'm gonna find that the fuel injectors are leaking or the fuel pressure regulator is bad.

Probably pull the rail and watch it under pressure and while cranking.

Would it be possible for the car computer to be over fueling the engine to this ridiculous degree?

Very close to curing the 240sx plague...

blkvrtswp

Fuel rail test is a great idea - if the injector o-rings are leaking, you will see fuel dripping out, that will flood the engine for sure. It's easy to rip those o-rings - try some WD40 on them when installing so they don't get pinched.

Sound like you are getting closer - good luck!

v30magna

Ok. Rail doesn't drip. Tried running the fuel pump 10 times with rail out.

Then crank tested with the rail out.

1, 2, 4 throw gas on every beat! (Is that right?)

3 doesn't do anything ( new injector). The old one was bad. Power at injector, signal wire has continuity from injector harness back to computer, no continuity with ground. Computer doesn't send a signal on 3. So I guess the computer is bad? Guess the old bad injector roasted the computer.

blkvrtswp

Yup, injectors "bank fire" on startup - all should spray. A bad injector should not typically burn out the ECU, though a short in the wires could. You can try 'sniffing' the ECU for burnt smell and pop-the cover off and look for melted or black spots.

Make sure the pin on the ECU plug has not pulled out for that injector. And be sure to tighten the 10mm ECU main plug bolt down all the way - that plug being loose can cause all sorts of odd problems.

A KA ECU should be relatively cheap and easy to find.

v30magna

Well the wire has continuity from the harness to the computer. Neither end has any continuity to ground (full resistance) or any voltage, so I doubt a harness short. I've heard a shorted injector could mess up the computer, and that injector was shorted.

I checked the signal right there at the computer and at the injector end. Nothing either place. Pin looked good, no burns, no oxy.

I'll probably check the radio harness too and make sure it was correctly installed to. People will hook a stereo to any damn wire that has volts.


Which computers plug in? Pretty much any auto? Mine is an auto

v30magna

Computer code is:

A11 b44 g07

Is there an interchange list somewhere? Couldn't find on search.

blkvrtswp

SOHC 89-90, right? Any ECU from auto 240SX from 89-90 will work. Post a Wanted To Buy here on Zilvia and you should get some responses.

Manual transmission ECU will not work for the auto though.

Look on Jim Wolf Technology's site - they have some pretty complete ECU charts to ID year from the numbers.

v30magna

I have a 92 auto twin cam, de, so any auto 91-94?

v30magna

I pulled the CPU covers. Looked like some green oxidation at the bottom edge of the board, like there had been liquid inside at one time. I used a copper brush to clean it, and one of the pins on the 8 pin logic chip beside the transistors had a pin that oxidized away (missing).

v30magna

Thx for info abt Jim wolf interchange. So the computer in the car now is for a manual trans 91.

So it is possible that at least some of the things wrong with this car are due to improper repair by previous owners.

What adverse affects if any could come from having the wrong computer installed? Anything I need to test before I install the proper computer?


Proper computer should be: a11 b45 g71.

blkvrtswp

Ah good - hopefully that ECU is the root of your problem. I've used AT ECU on MT cars many times, but not the other way. Might have some odd issues but I am not sure exactly what.

AT ECU should be easier to find, since many AT >> MT conversions have been done to S13's.

Keep at it!

v30magna

I have a full 5 speed swap waiting, but I'm not gonna do it until the car runs.

Gonna get some struts/springs and a VLSD soon too, then a few rear swaybars.

I'm too old for coil overs on the streets. Most people just try to do the sway bar's job with hard coil overs and end up hopping anyway.

I read somewhere that the auto computer is actually a minor performance upgrade over the mtx comp, but I cant confirm it.

I'm gonna order the computer tomorrow.

Thanks for all the help so far bud!

v30magna

also gonna do a cheap adjustable FPR for now too. That way I can tune the pressure just a few psi below factory pressure, until it stops fouling plugs. I'm pretty sure the factory fpr on there is at least getting tired. Everyone says these cars run rich.

v30magna

computer ordered

blkvrtswp

You're welcome. I think the car will grow on you once you can drive it and modify it.

I would really recommend a set of coilovers over any spring/strut combo out there. I have TEIN adjustable and they are fine on the street. The extra cost is worth it in the long run because few are satisfied with springs alone and end up buying coilovers anyway.

Try Facebook Groups - I see fair deals for coilovers on there all the time.

EDIT: Plus you can't fit wide wheels with the giant lower front spring perch....

v30magna

I'm not a coil overs guy. Don't need em. Not gonna track it. I understand suspension and driveline systems very well. I'm gonna run a pretty cheap suspension, don't really need wide front tires. Gonna get some tein s springs and some stagg struts. (When they blow, I'll buy more) I've seen good results from others that auto cross with them. Drove a car with them, I can live with it. I would run manzo springs ($91 shipped) but the front end sits too high with them.

I'm gonna run factory wheels, factory tires for now. Gonna get some 16inch wheels when the right ones come along. Nothing too wide. A 19 mm rear sway will finish it off. I can out drive most people with this setup. I can drive pretty good, and I've been building cars for abt 15 years. I'm the guy people come to with unsolvable problems. I haven't bought a running car or bike in 10 years. I don't go in for things I don't need.



I'm not really interested in anything you would find in a tuner mag. No stancing, no flush, no big camber. It's all a racket to sell parts...

v30magna

Guy sent me the wrong computer, and he sent my computer to someone else. He is johnson8850 on ebay. Buy from him at your own risk. more waiting...