1988 Pickup: 2 Questions

marloniusthunque · Feb 20th, 2005, 03:21 PM

Hi! this is my first post. Yay!

First, WHY does my four cylinder have EIGHT sparkplugs? How does that work?

Second, does anyone else have an ALTERNATOR that checks out as bad sometimes and good at others?

I'm beseiged by electrical gremlins

DanaCat · Feb 21st, 2005, 01:36 AM

Quote:

Originally Posted by marloniusthunque

Hi! this is my first post. Yay!

First, WHY does my four cylinder have EIGHT sparkplugs? How does that work?

Second, does anyone else have an ALTERNATOR that checks out as bad sometimes and good at others?

I'm beseiged by electrical gremlins

Welcome! Your truck has 4 Intake plugs, and 4 Exhaust plugs. The intake plugs burn the gas/fuel mixture and the 4 Exhaust plugs burn the extra exhaust fumes making the engine more efficient and cleaner running. Someone else could probably explain it better than that though. As far as the alternator, I am not familiar with that porblem. I know another bright person here could answer that one though....
P.S. You should have two different sets of plugs when you go to replace them, the 4 exhaust plugs should be a hotter range than the 4 Intake plugs. Someone at the auto store sold me 8 plugs all the same, and I just found out from a Nissan parts person that I should have two different sets of four plugs each (each set having a different heat range). Having 8 plugs all the same did cause me problems, one of the problems being prematurely fouling up and cracking 4 of the plugs on one side. So I took everyone's advice here and bought the NGK plugs directly from the dealership parts (making sure I got the plugs originally meant for my engine, and making sure I purchased the correct plugs for each side). For some reason, Nissans don't do well with electrical parts that are aftermarket. Most people here recommend sticking with Nissan OEM parts....just a few tips...

**88pathoffroad** · Feb 21st, 2005, 02:10 AM

You're right about the 8 plugs. The intake plugs fire the gas/air mixture to make the engine run in the forst place, and the exhaust plugs burn some more of the uncombusted fuel before it leaves the engine. It's just for emissions standards. It doesn't add any power, nor does it add any to remove the plugs and cap the holes off. *shrug*

The Nissan Factory Service Manual I have states you can use the same plug on both sides. BPR5ES is standard, BPR4ES is one range hotter and BPR6ES is one range colder.

Sounds to me like your alternator needs some very basic troubleshooting. Loose wiring plugs? Corroded cables? Look into it. KISS!

jacksapple · Feb 21st, 2005, 02:50 AM

I had a similar problem with my 93 Nissan Truck and the alternator. The problem ended up not being my alternator at all, but my starter. I took the starter apart and cleaned the brushes in it and everything has worked fine since. The parts store I took my alternator to said it was bad. I replaced it and ended up with the same problem. I then took my starter in to be tested and was told that it was fine... Which it was, once I cleaned the brushes and armiture. I don't always trust the parts store "tests".

DanaCat · Feb 21st, 2005, 03:13 AM

[quote=88pathoffroad]
The Nissan Factory Service Manual I have states you can use the same plug on both sides. BPR5ES is standard, BPR4ES is one range hotter and BPR6ES is one range colder.

Wait a minute...I went to the NGK website and it also gave me two different heat range plug recommendations - one range for Intake, and another range for Exhaust...what do you think?

NPath · Feb 21st, 2005, 04:00 AM

[quote=DanaCat]

Quote:

Originally Posted by 88pathoffroad

The Nissan Factory Service Manual I have states you can use the same plug on both sides. BPR5ES is standard, BPR4ES is one range hotter and BPR6ES is one range colder.

Wait a minute...I went to the NGK website and it also gave me two different heat range plug recommendations - one range for Intake, and another range for Exhaust...what do you think?

I've owned a 87 Nissan hardbody 4X4 for 10 years that uses 8 plugs. All 8 plugs were the Bosch BPR5ES's. Up here in Vancouver, Canada we have emission control testing called aircare and the truck always flew through the testing. So, in conclusion, doesn't matter if all were BPR5ES's.

Will · Feb 21st, 2005, 04:16 PM

My .02. I had an 86.5 and always used 8 plugs of the same #. I guess I just didn't know. The truck had over 500,000 on it when I decided to retire it from everyday use. And consistantly got 29 to 31 mpg. I just didn't know. I hope the Nissan gods forgive me. LOL