1992 Nissan Truck emgine misfire when warm/hot

92NISSAND21

MEMBER
1992 NISSAN TRUCK
4 CYL
2WD
MANUAL
255,000 MILES

When first starting, and for the first minute or so of idling, the engine is smooth. After that, it develops a miss and it will misfire about every 2-5 seconds at idle. Engine also has a pretty substantial miss when lightly on the throttle or when coasting.

I checked spark plug gapping and the wires are in good shape. I recently replaced many of the vacuum lines, but will test with vacuum pump. I also checked the amount of play in the EGR valve when the engine was off and the diaphragm moves fairly easily.

What should I do next?

Tuesday, April 13th, 2010 AT 8:56 AM

3 Replies

OBXAUTOMEDIC

MECHANIC
3,711 POSTS

Hello,

Ok you checked the plugs. What about the Cap and Rotor.

Remove the cap look inside at the electrodes if they look like they are corroded replace cap and rotor.

Post findings.

.

Was this

answer

helpful?

Yes

No

Wednesday, April 14th, 2010 AT 4:55 PM

92NISSAND21

MEMBER
2 POSTS

Cap and rotor look good (no substantial wear/no cracks), except: I recently replaced the timing chain and when I put the oil pump and distributor back on, the rotor wasn't pointing exactly at #1 when at TDC. Rotor was past #1, and I initially didn't think too much of it. I just recently retarded the distributor and the engine misfires much less and with less intensity, however now the idle is higher than it should be and it doesn't kick down in rpms like it should.

Do you think if I remove and reinstall the oil pump and distributor, and get the rotor to face closer to#1 at TDC, do you think that should do it?

Was this

answer

helpful?

Yes

No

Thursday, April 15th, 2010 AT 6:59 AM

OBXAUTOMEDIC