Hey,

New to the board, and got a serious problem. Well it's actually my friends car, i'm just doing the researching for her.

She has a 1992 Nissan Maxima with the DOHC engine. The car has something like 240,000 km on it.

Anyway she has notice in like the last 6 months the gas mileage has gone to crap, and that the car seems to lack power. And it has this weird hesitation.

My first thought was head gasket, but after giving the engine the once over there isn't any indication of it having a head gasket problem(such as there isn't any oil in the coolant, and vise versa) and there doesn't seem to be any reminance of coolant leaks around the heads at all.

So i drove it, car seems to drive fine, and doesn't seem to be lacking power(the lacking part could just be because of the higher km). And well i didn't drive it enough to notice the gas mileage(again high km could be contributor). As for the hestitation, she tells me while we're driving that it doesn't do it all the time, more like hardly ever. And tells me it does it more when you're climbing a hill at a constent speed. Also she said it sometimes happens when she turns the heat on. Which is when it did it for me.

The hesitation is characteristic of an engine lacking fuel, the car lurched back and forth for about 5 seconds, then it went away. So right away i ruled out head gasket, because it wasn't having this strange problem all the time, it was random rather. So i'm think it's something electrical. She's had the fuel pump replaced and the fuel filter, and fuel line cleaner put through in the last year. The oxygen sensor was done around the same time as well. Also when the hestitation happened, the car had lots of fuel.

My guess was going to be maybe the throttle position sensor(TPS) or MAF/MAP or whatever these cars have, or maybe the cam position sensor(or whatever these cars have).

I've done some searching on the internet, and it seems there are a lot of people that have had this problem(or something similar) but there didn't seem to be anyone who had a real remedie for the problem. Some had tried several things, and didn't help, where others had done similar things and it worked or worked for about 6-12months then went back to the same problem.

Hope i've provided enough info here, hope someone can help. Thanks

PS: This car has an automatic tranny, if that makes a difference.

 

i think i have the sme problem also...so any help guys would be great...

 

gas mileage I would replace the o2 if it hasn't been done recently.

the other problem sounds kind of like my intermittent injector problem, but I'm not 100% sure.

 

Do tst all sensors, one by one. Do PM on the harness, connectors, groundings... read all through, start from: http://www.cardomain.com/memberpage/748507/14

 

The coil packs would be my first guess. There are about a dozen or more drivers on this board with the VE30DE engine (DOHC) that have experienced this lurching/hesitation problem.

They run about $60+ (US) each, so it would be a good idea to test the resistance on them before replacing them all. If you do a quick check on the front ones, look for cracks. That is a tell-tale sign they need to be replaced.

Wiking is definitely on the right path with checking all of the sensors and connections.

 

I've no coilpacks experience: Have u tested cleaning cracked coilpack with electronics cleaner and insulating with self vulcanizing rubber tape?

--->Lacquer works miracles on cleaned, cracked distr cap...

 

what should the resistance be one each of the coils if they're in good shape? Obviously if there are one or two numbers that are a lot lower than the others, i'd know that those coils were bad.

Can i use a standard multimeter to do the test, or do i need something else?

 

1. Coil resistance is one matter: DMM gives no reading if broken

2. Insulation leakage is another: DMM no use. Take Bright (I mean BRIGHT) light, magnifying glass, search for cracks. IF cracks:Try to repair... cleaning cracked coilpack with electronics cleaner and insulating with self vulcanizing rubber tape. Works, have no hands on experience how long...

Empirical test is best: test all coilpacks one by one with a spare (grounded) spark plug.

 

According to notes I took from MrGone a while back, resistance on the coil packs should be .8 ohms and the voltage should be 12. The information is in the FSM somewhere, but I am far too lazy to dig through mine.

The cracks are very obvious. Mine ran north and south along the front coil packs. I taped them at first and it seemed to help the idle some, but it still hesitated. First I replaced my front ones. I still had the problem. The rear ones all looked great, so I started replacing everything else: MAF, TPS, Cam Sensor, ignitor, ECU, spark plugs.

Eventually, I just replaced the rear coil packs and it solved my problem. I live by a freeway, so I just kept putting in one at a time, driving on the freeway (hammering the throttle) until I figured out it was the rear one on the passenger side. Not the best way to do things, but it was a Sunday and none of the parts stores here were open to get a multimeter. I still need to buy one...crap, I am lazy

On a side note, I also talked to a Nissan Tech that told me Bosch spark plugs don't react very well with our coil packs for some reason and can cause surges or "spikes." It is a good idea to stick with NGK plugs. You don't have to get platinum ones. Coppers work just fine as long as they are the right temperature range, they just don't have as much longevity as the platinums.

 

I am having similar problems and it's the distributor cap in my case

 

Here we wash the VE: price...

Btw. rewire your VG: http://www.cardomain.com/memberpage/748507/12


What was the Last Sound before stillness fell? -bosch-

 

This question was asked about a VE engine. It's a totally different set up. Coil on plug -- no distributor.

 

http://www.autozone.com/servlet/UiBr...3d801f478b.jsp

 

You sent the wrong link. That is the test for the SOHC engine's single ignition coil. Here is the right link for testing the indvidual coil packs on the DOHC engine: http://www.autozone.com/servlet/UiBr...3d801f463e.jsp

 

Doh, n/m I stand corrected.

 

Thanks for all the help, I won't be able to try these suggestions until the weekend. But I'll make sure I post and let you know if this ends up being the solution to the problem.

 

So i was finally able to get the time to look at the car. Checked out the coils visually and i couldn't see any cracks or anything. Checked the resistance on them, and they were all 1.0 to 0.9 ohms. Is that acceptable? I know they're suppose to be at 0.8, so i would assume the numbers i had would be acceptable.

Any other input as to what might be the problem?

Thanks again for all the help