darrellk65

Hey guys I'm in need of a little help. I have a 1986 1/2 Pick-up with a z24I engine. It's been cutting out and idling rough for the last month or so. I've changed the distributer cap and rotor, air filter, fuel filter, plugs and a few vacuum hoses that were cracked. Then today I was driving down the road and it just died. It won't restart at all.
When I popped the hood I had fuel pressure after the filter so I don't think it's a fuel problem. The only error code is #21
What exactly is #21 and what do I need to do to fix it. Thanks

Darrell

Ravetrancer

here are som error codes, also the 21 is included:

11 crank angle sensor circuit

12* air flow meter circuit

13* engine coolant temp. sensor circuit

14* vehicle speed sensor circuit

21 ignition signal circuit

26* boost pressure sensor

31* ECU

32* EGR function

33* exhaust gas sensor circuit (left)

34 detonation sensor circuit

35* exhaust gas temp. sensor circuit

42 fuel temp. sensor circuit

43* throttle position sensor circuit

45* injector leak

51* injector circuit

53* exhaust gas sensor circuit (right)

54 signal circuit from A/T control to ECU

55 NO malfunctions in the above

nissanjunkie

I have/had the same code myself but the haynes manual doesn't tell how to fix it. It just says" The ignition signal in the primary circuit is not entered during carnking or running. This repair must be performed by a dealership service department." I may have to take a trip to a freind of mines shop to find out what to do off of all data.

Edit: I just went and checked the computer on my truck.It looks like the rotor, cap, wires and autolite platinum plugs I put in it a few weeks ago fixed what was wrong with it. I had the Bosh plugs in before and thats when the code came on if I'm not mistaken.

__________________
88 Nissan Hardbody V6 4X4 off-road rig.

Bosch spark plugs are the leading cause of ignition problems on NF!!!!!!!!!! When will you all learn????????? :mad:

darrellk65

I've changed the fuel filter, air filter, plugs, cap, rotor, exhaust ignition coil and power transistor. I still have a problem of the engine cutting out at about 2000 rpm. The only error is #21
I can drive the truck down the road as long as I don't give it much throttle. As soon as I accelerate much at all it just stalls. When you get back out of the throttle it runs OK again. It's got me a little baffled. I'm going to ohm the throttle position sensor to see if its all right.
When you turn the key on you can hear the fuel pump run for a few seconds and then it shuts off. There is pressure on the fuel line after the filter at this point so I don't think the pump is bad.
Last night I unplugged th exhaust ignition coil so there is no spark going to the exhaust spark plugs. The truck runs identical, doesn't seem to make any difference at all. Still cuts out though.

nissanjunkie

Like I said before, mine went away after a few part replacements but you have a few more parts to replace than I do. Are your plugs Bosch?? If so they may be causing the problem. Try changing the other ignition coil to see if it fixes it after everything else ignition wise checks out. Only thing left to change is the distributor if you replaced the rotor, cap, plugs, wires and both coils.....it has to be something ignition related to cause the engine to give you the code. I would start over with the basic diagnostic procedures : spray starting fluid in the intake and if it runs for a short amount of time then its a fuel problem ; if it don't then you check to make sure the engine is getting spark up to the end of the wire with a spark plug wire tester. Test the spark plug wires with an ohm meter they should give an amount up to about 20,000 ohms but anything less is ok but any wire that gives an O L on the meter is bad and needs to be replaced.

__________________
88 Nissan Hardbody V6 4X4 off-road rig.

Bosch spark plugs are the leading cause of ignition problems on NF!!!!!!!!!! When will you all learn????????? :mad:

darrellk65

A little more history.

Last week I was trying to start the truck, I used starting fluid but it didn't help. I let it set for a couple days and tried to start it again. It started but died almost immediatly. I tried starting fluid then also but it didn't have any affect.
The next day I picked up a used exhaust coil from a salvage yard. Installed it and the truck started right away. Buttttt, I took off down the road and it started cutting out again. So I can start the truck every time just fine but I'm back to cutting out at half throttle.
The plugs I took out were Bosch Platinum's. They have been in there for about 3 years or so. I changed the plugs to NGK but there was no improvement. Still cut out.
Should the truck start up and run with either coil? I disconnected the exhaust coil and tried to start the truck and it wouldn't start. But if I disconnect the intake it will start and run with just the exhaust coil.(I posted earlier that I unhooked the exhaust coil and drove the truck but actually it was the intake. My bad).
Is the throttle position sensor just an off on switch? If not, do you know what the ohm value range should be from zero to full throttle. Thanks

Darrell

nissanjunkie

Its best if you have both coils running at the same time. The exhaust side ignites the gas again to reduce the amount of pollution and wasted fuel. The throttle position sensor is a potentiometer and it works sorta like a thermostat, the more its opened the more voltage it sends to the computer thus telling the computer what position the butterfly plate is at. I don't know the specs (anybody got em??) but the resistance should gradually decrease the more you open the throttle with no point in between when its almost closed and when its WOT where the resistance goes to O L on your meter display. If there is an open spot in you TPS then it is bad and needs to be replaced.

__________________
88 Nissan Hardbody V6 4X4 off-road rig.

Bosch spark plugs are the leading cause of ignition problems on NF!!!!!!!!!! When will you all learn????????? :mad: