# '92 Sentra won't start HELP!



## jseabolt (Nov 2, 2013)

I hate to use that as an subject but that's the problem.

Here's some info:

A friend of my wife asked me to look at his 92 Sentra. 210,000 miles, a $300 car if it did run. First I got to get it running. Once I do that, then I have to replace the axle and wheel bearings.

He said last time it was running it was running poorly (no power) and it started stalling. He got it back to his apartment and it has sat since last March. After he towed it to my house I can't get it started. It acts like it wants to start.

The car suffered a cat converter meltdown and the converter has been replaced with a straight pipe.

First of all I can't get the check engine light to flash to retreive any engine codes. There are two methods I have read about. First one:

Turn the ignition switch on, wait three seconds, press the accelerator 5 times, wait 7 seconds then hold the accelerator to the floor, the check engine light should start flashing but it won't go off. Also no after no amount of time will the check engine light go off.

So I pulled the covers off the center console to gain access to the ECU. Supposably there is a screw you turn one way and this is suppose to cause an LED to flash on the ECU.

Well there is no screw or LED!

Some things I have done so far:

Check plugs. Assuming the one on the pulley side is #1, that one was carbon fouled. Leaking injector that fried the converter perhaps? All other's look OK.

Checked mass air sensor. To the best of my knowledge it's good. Clean inside and when I measure the voltage at one of the wires it read .7 volts. According to the Chilton's manual it's OK.

If I disconnect the brake booster hose and spray starting fluid into the hose and plug it off and hit the starter, the engine will idle for about 3 seconds. So the ignition system seems to be OK.

Checked fuel pressure. 40 PSI after I turn the engine over a few times.

Compression test: 95,85,100,85 lbs.

That sounds a bit low. I tested my Fiat's compression afterwards on an 8:1 C/R twin cam and got 120 lbs and that engine is a bit worn out. I would expect higher on the Nissan assuming it has at least a 9:1 to 10:1 C/R. But the engine does have 210,000 miles on it.

The weird thing was I thought the injectors were not firing but while doing the test it appeared at least 3 of the plugs were wet. So it has spark, fuel but won't start? Jumped time?

What's it gonna take to figure out why this engine won't start? How can I retrieve the stored codes? I have an OBD II reader but of course it won't work on this car.

I found a similiar type of plug when I removed the fusebox cover. Is that the OBD I connector?

This car needs A LOT of work. Seriously it's a $300 car but is transporation I guess.

Any other help appreciated. Thanks.


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## worthirt (May 21, 2013)

The connector that you speak of is the CONSULT connector. you may not find the ECU screw or led, I have a 94 and they were hard to find. I finally found them on the back of the unit. Since then I got my CONSULT cable and Nissan data scan so I can easily communicate with the ECU (it's not necessary though).

Have you checked your vacuum lines? I found that a couple had gotten really dry-rotted and was causing mine to idle like crap and the check engine light to turn on. Ended up to be the hose on the bottom of the EGR that did it. I did find that another one was going bad, it was connected to the fuel regulator (it's on the intake near the end of the fuel rail), luckily it hadn't caused a problem yet. The fuel pressure test may be good because the test point my have been before the regulator. 

Compression does sound a bit low, but if it runs on starting fluid for a few seconds, I don't think compression is the problem in this case.


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## smj999smj (Jan 1, 2006)

I think you already found the problem: the compression. Assuming this is a GA16DE, standard compression is 192 PSI @ 350RPM. Minimum compression is 164 PSI and maximum limit between cylinders is 14 PSI. I would suspect either the cylinders have been washed down with fuel or the timing chain jumped. Did you try doing a "wet" compression test by adding a little oil the cylinders and see if the compression pressures raise to the proper specifications?


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## jseabolt (Nov 2, 2013)

smj999smj said:


> I think you already found the problem: the compression. Assuming this is a GA16DE, standard compression is 192 PSI @ 350RPM. Minimum compression is 164 PSI and maximum limit between cylinders is 14 PSI. I would suspect either the cylinders have been washed down with fuel or the timing chain jumped. Did you try doing a "wet" compression test by adding a little oil the cylinders and see if the compression pressures raise to the proper specifications?


I'll have to check the door jam sticker but GA16DE sounds right. It's a 1.6 liter DOHC. Looks like a DOHC engine.

It's been ages since I did a compression test. I thought I might have done it wrong. I forgot to shoot oil into the cylinders until after I did the test. One thing that puzzles me was as I was cranking the engine over, the pressure on my gauge would drop to 30 lbs then I'd have to "catch it" until it read the highest pressure.

I thought the check valve may be bad in my compression gauge and it could be bleeding off between cycles but once it's hits 90 lbs, the gauge holds. What's up with that?

I got the same result with my Fiat 131. It would build up to 120 lbs then on the next cycle fall to 30 lbs. Then go back up to 120 lbs.

it was my understanding the gauge should stay at whatever the highest pressure should be. It's as if when the engine is on it's down stroke, it pulls negative pressure on the gauge and gives a lower reading. Which I don't think it should do.

It's over 15 years old but hasn't been used all that often.

Maybe I should get a new gauge, do a wet test and try again? But I do know 90 lbs was the highest pressure the gauge read when cranking the engine over because I was watching it while cranking.

Could the check valve in my gauge be bad?


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## jseabolt (Nov 2, 2013)

worthirt said:


> The connector that you speak of is the CONSULT connector. you may not find the ECU screw or led, I have a 94 and they were hard to find. I finally found them on the back of the unit. Since then I got my CONSULT cable and Nissan data scan so I can easily communicate with the ECU (it's not necessary though).
> 
> Have you checked your vacuum lines? I found that a couple had gotten really dry-rotted and was causing mine to idle like crap and the check engine light to turn on. Ended up to be the hose on the bottom of the EGR that did it. I did find that another one was going bad, it was connected to the fuel regulator (it's on the intake near the end of the fuel rail), luckily it hadn't caused a problem yet. The fuel pressure test may be good because the test point my have been before the regulator.
> 
> Compression does sound a bit low, but if it runs on starting fluid for a few seconds, I don't think compression is the problem in this case.


I did check the hose between the mass air sensor and throttle body which will typically cause an engine to fail to start and it's OK. The hose going to the regulator was in bad shape so I replaced it but it made no difference. I'll check the EGR hose.


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## smj999smj (Jan 1, 2006)

Sounds like the valve is bad in the compression gauge. Some uses a standard shrader valve like those used in tire valve stems. I would do the compression test again with a know good gauge. 90 PSI is way too low. A problem that seems to becoming more frequent on high mileage or older GA16DE engines is the upper chain tensioner falls apart and causes the upper chain to slack and jump timing. This can caused bent valves and often strips/damages the teeth on the timing main gear.


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## jseabolt (Nov 2, 2013)

smj999smj said:


> Sounds like the valve is bad in the compression gauge. Some uses a standard shrader valve like those used in tire valve stems. I would do the compression test again with a know good gauge. 90 PSI is way too low. A problem that seems to becoming more frequent on high mileage or older GA16DE engines is the upper chain tensioner falls apart and causes the upper chain to slack and jump timing. This can caused bent valves and often strips/damages the teeth on the timing main gear.


The way the engine turns over leads me to believe the engine has either jumped time or is out of time but since they engine will idle off starting fluid makes me wonder.

After doing the compression test and noticing wet plugs now makes me think the engine could be flooding out instead of not getting any fuel.

Due to the over all condition of the car I'm really considering telling my wife's friend I don't want to mess with this thing. It's a basket case.


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## dreamteam (Jul 29, 2005)

Check the voltage on the o2 sensor


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## jseabolt (Nov 2, 2013)

dreamteam said:


> Check the voltage on the o2 sensor


Would that cause the engine not to start?


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## smj999smj (Jan 1, 2006)

No...it wouldn't cause it not to start. I think you have a lot bigger issue than just a bad O2 sensor.


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## b13er (Apr 7, 2010)

I thought my ecm had no screw for the longest, finally after taking it out a third time I realized the screw was behind a sticker. I could feel the hole behind the sticker, and so I punched a hole through the sticker and there it was.


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## b13er (Apr 7, 2010)

&
The ECM has fail safe modes, if your MAF is broken it uses the TPS and compensates, but you're only allowed to go up to 2400 RPMs. If the TPS is broken it judges idle position by amount of fuel injected and engine speed. So theoretically neither one of those being broken will immobilize your car. Actually I've driven around with my TPS accidentally unplugged, it wasn't pretty but it ran.

The first thing I would want to do is take out the spark plugs and let all that gas in the cylinders evaporate. It worked for one guy on this forum.

Next I would test every spark plug cable with a spark tester: Amazon.com: Rotary # 9773 Adjustable Ignition Spark Tester: Patio, Lawn & Garden


Next I would check the timing: set the #1 cylinder (far left) to TDC. Take off distributor cap and make sure the rotor is pointing at the #1 cylinder (where the #1 cylinders spark plug cable goes). It might end up pointing to #4, and if you do another revolution of the crank it will end up pointing to #1. It takes two crank revolutions for every 1 turn of the camshaft.

A bad ECM could be your problem: turn key to on position (but don't start the car) the light should be on, this is the bulb check. Now start the car, there shouldn't be a check engine light on immediately, if there is it's a bad ecm. 

Also do a diagnoses test by turning the screw - wait 2 seconds - and then turning it back (again mine was hidden behind tape).

A common thing we are seeing in this forum are bad distributors. Making cars run bad or not start. The worst part is the only known diagnoses is to replace it with a good known distributor. You might be able to get one cheep at the junk yard, but as many that I've read about failing on this forum, you might get another bad one since they are immobilizing cars and tricky to diagnose.

I would invest in a new compression tester if I were you.


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## jseabolt (Nov 2, 2013)

smj999smj said:


> I think you already found the problem: the compression. Assuming this is a GA16DE, standard compression is 192 PSI @ 350RPM. Minimum compression is 164 PSI and maximum limit between cylinders is 14 PSI. I would suspect either the cylinders have been washed down with fuel or the timing chain jumped. Did you try doing a "wet" compression test by adding a little oil the cylinders and see if the compression pressures raise to the proper specifications?


Sorry for reviving an old thread but this car is still on my property!

So if the engine has 90 lbs of compression, it won't even start? 

Initially this car needed new wheel bearings and/or CV joints. So I said, yeah I can fix that. I thought he was going to drive it over to my house but he ended up dumping it off at my house off a rollback and said he couldn't get it started. So I don't know if he lied to me because his apartment manager told him to get the car off the premises or it did actually run 4 months prior but not now.

I may have mentioned this but the guy who owned it told me he was driving it and it started loosing power and the most it would do was 30 mph at full throttle. Then it started picking up power. He drove it home and that was the last he drove it.

He did say a muffler shop said the converter was coked up. I don't know how he would know that without pulling it off and looking in it. I saw in my original post that the converter had been replaced with a straight piece of pipe. I can't remember him telling me that. I'll have to check it out.

I put it up for sale on Craigslist and had some calls but can't get anybody to buy it for $300. Although a free site, I hate trying to sell stuff on there. Some people called me up and asked me why it wouldn't start. I replied, "If I knew do you think I'd be selling it for $300?"

So the owner dropped it down to $200 because some idiot told me over the phone that he would buy it for that price and came out and looked at it but never called me back!

He brought the title over and signed it so technically it's my car now. 

A co-worker's cousin runs a salvage yard and said he wanted to buy it but did not have the time to pick it up this week. 

Then my wife approaches me and asked me if I could get it running for her son who needs a car. My step son and I don't really get along so I'm not all that enthusiastic about getting it running. Besides he will wreck it within 2 months so I'd hate to put all that time and money into it. I hope that doesn't sound mean of me. Just calling it like I see it.

Of course I would not invest in major bucks in this car. Just patch it up enough with used parts to get it running.

It's been 2 years since I fooled with this car but I started reading back on my original post and wondered about something.

I mentioned that the engine would run on starting fluid for three seconds then die. Yet three of the plugs looked wet after cranking. I mentioned that I was getting spark but can't remember if I just touched the end of the plug wire to the engine or plugs to the engine to see if they were actually firing. I did not think about bead blasting the plugs to see if this did any good.

Would a fouled plug run on ether but not gasoline?

Here is the car in it's current shape :


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## jseabolt (Nov 2, 2013)

So today I bead blasted the plugs. I know your not supposed to bead blast iridium plugs but wanted to see if that was the problem.

Still nothing. I tested spark directly from the coil. I am getting spark from the coil.

Tomorrow or sometime I'm going to connect my node tester (or an LED test light) to see if the injectors are firing. I assume the cold start valve is the one with the purple connector?

Last time I used my compression tester on my Trabant 601 it held pressure at 115 and 130 lbs (it's a 2 cylinder 2 stroker) as I turned the engine over. With the Sentra, the gauge pumped up to 95 lbs but if I keep turning the engine over, the compression fails. So I don't know if the check valve in my gauge has went bad or this is some kind of sign the engine has jumped time. I can't remember if I did a "wet" test or not. I'll have to check my gauge against a known good engine and retest my Sentra doing a wet test.

It looks like the timing belt (or chain? which is it) cover is hard to remove. But the valve cover looks like it's easy to remove. If I pull the valve cover off, can I tell if the engine has jumped time? A friend told me this is good to do anyway because he bought a Honda Civic with a locked up camshaft.

Does this Sentra have an interference engine? Since it does build up compression (although 95 lbs) I suppose that means something.

I once bought a Fiat Spider (I'm into pre 83 Fiats) where the machine shop had accidentally swapped the cam gears, which resulted in 60 PSI. Then when I got them timed correctly I got 120 lbs.

Here is a video I took 2 years ago trying to start the Sentra.

https://www.youtube.com/watch?v=TdhjPTfoT2w


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