Top 20 1991 Nissan Pickup Questions & Answers

It is definitely mechanical - you are going to need to open up engine until you find a problem - focus on the timing chain

Take the engine belts off one at a time and start the engine if the noise goes away then you can isolate the problem by what the belt turns and after the belts are off and your noise is still there you may have an internal problem with your engine

Fuel injectors may need cleaning.

Could be a bad chain guide or tensioner.I've got a 85 Nissan 720 4x4 2.4 with a Weber carb.Had her since 1993.It had 108,000 miles on it when I got it.Not long afterwards,Carb went bad,no one could rebuild it,tried 3 places.Finally took to Nissan Dealer,they told me that the carb was a bad design and they could not rebuild,they told me it was junk,they were right,not long afterwards motor went bad,so I got a remanufactured Jasper motor,with 3 year-or 100,000 mile warranty,got it in 2009,I now have 61,000 miles on it with a new Weber carb and it runs awesome,never ever had a timing chain issue,speedo now has 344,000 miles on it.Had the engine installed by a Jasper engine installer,a pro,seems like whoever has been putting timing chains in your engine is clueless on these 2.4 engines,our Nissan's have a history of head gaskets blowing,never timing chain issues.Here is a link on how to replace your Timing chain. Repair Guides Engine Mechanical Timing Chain And Tensioner AutoZone com Here is a photo of mine,need more help,let me know.

pull the door handle if door is unlocked the latch should snap open.

The basics, make sure battery has a full charge. If it cranks good but won't start, have a helper crank it while you check for spark at the spark plugs. If spark everywhere, use a gage and check proper fuel pressure. Also check fuel injector pulse. Any applicable trouble codes? Your obd1, you should be able to check some codes, yourself. You can try cycling the key on and off several times before you crank it, when problem is ongoing, if that helps, I think it's a fuel issue.

BAD BATTERY OR BAD ALTERNATOR.

Counter clockwise is the rule.

There is no capacitor on that electric motor. They are not well made and have to be replaced. http://www.autopartswarehouse.com/shop_years/nissan-d21-blower-motor-1991.html

Try this site: http://www.2carpros.com/diagrams/nissan/pickup/1991

Sounds possibly your fuel filter is clogged

Autozone lists that engine timing at 10 degrees before top dead center with the engine warm and idling at 800 RPM. That is with the transmission in neutral (parking brake on) and all accessories off. It also states timing and idle speed are electronically controlled and non-adjustable.

to add, nissan on the days of OBD 1, had a CONSULT port Nissan Consult OBD 1 OBD1 14 PINS USB 19892000 DDL Scantool interface the other old-school way was to access the ECU of the vehicle itself & turn the screws to set it to "trouble code mode" and watch the flashing LEDs and count them...

lots of air pressure may have move out of place the wires. unplug, clean and plug back in each wire you may see that got in contact with the high air pressure. hope this may help you... chevy pick ups have this issue. instrumental board stops working properly around 120,000 miles. gauges for gas,temp,oil,speed will not work properly. unless this happens under 100,000 miles you are covered. if not. 265 dlls ..this is what i paid for a chevy 2003 5.3 v8 vortex to get it repaired

Remove oil filler cap which is normally on top of the rocker cover look at underside of cap, the side that goes into rocker cover, and if it is covererd in a white oily substance or if the tube that the filler cap goes into has the white gunge in it yo have oil and water / coolant mixing in your engine

Tune up, EGR valve dirty, collant temp sensor bad, IAC dirty.

1- check battery and see if the battery lights comes up on the dashboard prior to start.
2- does it start? If not the alternator could be affected and not charging battery.

Do you mean it is shifting poorly/slipping, or are you wanting harder shifts than stock? If shifting poorly, when did you last replace trans fluid and filter?

Put headlights on and turn over engine! If lights dim and car won't start probably battery bad!

Check the compression on the cylinders.