# HELP !! 90 sentra wont start !!



## ahardb0dy (Nov 9, 2003)

Hello all, NEED HELP !!!!!

My former 90 sentra I sold to my step daughter and her BF, won't start.

Back ground:

She said the car was running hotter than normal around the 3/4 mark, previously I replaced the water pump and thermostat and added new anti freeze.

She was driving it to my house and the temp was running around the 3/4 mark, she turned the heat on and the temp went down, she continued to drive and down shifted and said it backfired, she saw smoke in the rear view mirror and a few minutes later she said the temp gauge dropped to cold and than the car died.


She had it towed to my house and I started looking at it, I flushed the radiator, overflow and block out and started to fill it with water, until I heard water leaking onto the ground, I found a hose under the intake manifold was split, hose goes to the TB.

I pulled the plugs and checked them, they were shot, step daughter and her BF are not good with maint. he finally changed the oil after about 20K miles !!!!

I replaced the plugs and tried to start the car, it cranks fine but won't start, I checked for spark on two plug wires and it has spark, I pulled the output off the fuel filter and had my wife turn the key, the fuel pump does prime and it started to pump fuel into a container I was using to catch any fuel.

I tried pouring gas into the TB but it still won't start.

I removed the distributor cap and cranked the engine to make sure the rotor turns, it does.

I replaced the injector with an older one after it failed the resistance test per the FSM, manual says if the resistance is not between 1-2 to replace it, I got 3.4 ohms, the old injector tested at 1.2 ohms so I swapped them.


Tonight I pulled one of the plugs and it was covered with gas, pulled another plug and it too was covered in gas, had her crank the car and gas came out of the cylinder ( all over the front of my house !),

I removed the fuel pump fuse and cranked the engine a few times, than it started raining so I had to stop.

The first time I had her crank over the engine I thought I heard what sounded like water leaking but no water was leaking, coolant is empty at the moment.

I think it was gas pouring into the TB so the old injector may be stuck open.


Really need help with this on what I should do next, need this car fixed ASAP.


Thank you all, I don't have a compression tester or fuel pressure tester but will get one if needed


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## Galimba1 (Aug 16, 2002)

One guess - that the time it backfired, the temp gauge dropping to cold, could water from the burst hose have shorted something (associated with themp gauge circuit)? Check all fuses. . .

Compression check should rule out damage from backfire, and if you have spark, then I'd look for a replacement injector. 

If you disconnect the injector or fuel system, and pour a little fuel down the TB, would it catch and turn over or nothing?


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## ahardb0dy (Nov 9, 2003)

Thanks for responding,

I tried pouring a little fuel into the TB with the fuel pump fuse disconnected, also tried with starter fluid. I swapped back to the injector that was in the car last, I can see it spraying fuel into the TB, I swapped the coil to an extra one I had also.

Nothing !

When you floor the gas pedal it sounds like it wants to start but it still won't.

Also pulled the valve cover to make sure nothing was weird, had step daughter crank it over as I watched and all looks normal.

I'm thinking may be a compression issue, no idea what else it could be.

The hose that split was one of the 2 that come from under the intake manifold up to the TB, the only thing electrical in that area is the oil pressure sender.

I don't have a compression tester so was going to have it towed to my mech. buddies shop and let him take a crack at it.


No sentras (or pulsars) in the local junkyards to pull parts off of, would hate to have to buy a injector or fuel pressure regulator if it wasn't the problem.


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## BeyondBiscuits2 (Jan 18, 2006)

I'd suggest renting a compression tester from your local parts house and doing a compression or leak-down test. This will tell you if you have a bad head gasket, bad intake manifold gasket, etc. Nissans in the '90s are notorious for bad intake manifold gaskets, so I'd check that. Also, I'd have a look at your coolant temp sensor, and also the MAF sensor. Have you checked the engine codes on the ECU under the passenger seat yet?


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## ahardb0dy (Nov 9, 2003)

I checked for codes there were none


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## BeyondBiscuits2 (Jan 18, 2006)

All a combustion engine needs to run is fuel, spark, and compression. You've checked the fuel, and that seems to be functioning, albeit perhaps too much so as the plugs are wet. The engine's coolant temperature sensor, when bad or malfunctioning, puts the ECU in safe mode and dumps fuel as it believes it is below freezing outside. Also, have you tested your fuel pressure regulator? I can see how the CTS would go bad with the vehicle overheating, but I wouldn't find a correlation with the FPR unless it just ironically "went bad" at the same time. You've checked for spark, which seems to be functioning properly, so we can rule out distributor and CPS issues. Lastly, compression. If she overheated it, she could have popped the head gasket. Unfortunately, that's about all the help I can offer...


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## ahardb0dy (Nov 9, 2003)

Does the CTS throw a code?

Thanks for the help, I picked up a compression tester today from Harbor Freight, was at the junkyards looking for parts for my new project truck (93 Hardbody king cab 2wd 5 speed KA24E)

Just got done swapping parts I bought, will try to test the compression tomorrow

Will post back,

thanks


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## ahardb0dy (Nov 9, 2003)

Just checked the compression, don't think it looks good,

Readings:

cylinder
1 - 59
2 - 59
3 - 94
4 - 131

added small amount of oil to 1,2 & 3 and re-tested
1 - 119
2 - 100
3 - 121
4 - did not retest

Service manual shows compression specs of:

standard - 181
minimum - 142

no more than 14 difference between cylinders


So time to look for a engine possibly?

Thanks


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## BeyondBiscuits2 (Jan 18, 2006)

I'd say your compression test says it all. How many miles are on the engine? You could get away with doing a rebuild, considering GA16is are few and far to come by these days. I'd suggest doing a leak down test first, though, as that will confirm whether it is the rings, valves, or head gasket. If it is the head gasket, just fix it on go on about your business.


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## ahardb0dy (Nov 9, 2003)

Hello, thanks been waiting to hear some responses.

Not sure on the exact miles, think it is around 276K, the engine is all original other than normal gaskets and a few things that I had to replace ( distributor was leaking oil, has a new surplus one on it), timing chain and guides are original as far as I know.

So if the hose blew first draining the coolant and than the head gasket took a crap, I know from researching if the head gasket is bad between two cylinders that would cause the compression test readings on those two cylinders to be low.

I also read that if adding oil to the cylinders raises the compression number than most likely it could be a ring issue and not a valve problem.

So without tearing it apart, could the head gasket possibly be the whole problem?

It would be a lot cheaper to replace the head gasket and have the head checked than to either rebuild it or try to find another engine ( or at least the block).


I thought the DE engines used the same block but now I read that the pistons are not compatible from the DE engine as they have 4 valve reliefs on the top of the pistons compared to the 3 that the GA16i head has.

Thanks for all your help.

The car has so many new or fairly new parts I would hate for my step daughter to have to junk it and all the parts I added go to waste.


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