KA24E cold start issue

[68Datsun510]

Hey folks, today I come to the engine forum not for the Dime, but for my hardbody truck. Its a 97 with a KA24E. 174000 miles. All stock. Cold starts almost always result in a truck running on 3 cylinders until it warms up or you rev the piss out of it. Ignition system all Nissan brand less than 5 years old.

 

Other symptoms include a general lack of power all the time, an idle thats slow to catch itself, falls to +/-400rpm before the IACV kicks it back up. The harder/longer you drive it the weaker it gets. Its been  progressive issue over the years.

 

I do know the cat is going bad, passed smog by ONE point last time... could a clogging up cat be the issue???

[MikeRL411]

Cloged fuel injector and/or fuel line filter?

[Eagle_Adam]

im with mike, every time i have fuel issues i replace the filter. Seems to solve half the problems i run into 

[q-tip]

A plugged cat could cause some problems, put your hand at the tail pipe and have someone rev the piss out of it, if its not blowing your hand out of the way or blowing exhaust with some force, the cat could be plugged up. EXHAUST IS HOT!!!!

 

 

I would agree with Mike and adam, start with a fuel filter

[what]

Does the exhaust smell like rotten eggs?  When you replaced the distributor did you use a timing lite?  Have you ever tried running any of those fuel injector cleaners in your gas tank? Auto or Manuel transmission?

[what]

Almost sounds like a cracked distributor cap or bad rotor.

[Uber Deaf One]

FWIW, I recently replaced the distributor cap and rotor on my dual cam KA (they were 2-3 yrs old) and the engine ran much better.  Smoother, stronger idle, more power, better gas mileage.  5 years is quite some time to go without replacing basic stuff like cap n rotor and fuel filter.  Could be injectors... maybe check the spray pattern.

[mhub91]

Let's do a proper diagnosis on this :D

 

First off, are there a check engine light? Malfunction indicator lights? Anyone lights on what so ever? Even a brake warning light?

 

Does it smoke?

 

Next, let's pinpoint the troubled component.

 

While the vehicle is showing symptoms let's try to figure out which cylinder is causing a misfire.....

 

While running and acting funny, pull the spark plug wire to each cylinder (one at a time, of course.) DO NOT pull injector harness to cylinders, this will cause a lean condition!!!

 

Which cylinder WAS NOT affected? -> this is the cylinder that is missing. (we know this because if the spark is cut to that plug and idle is NOT affected, that cylinder has been misfiring prior to cutting spark to it)

 

Are you still with me?  :confused:

 

Tell me what you find from here......

[68Datsun510]

Manual, no rotten eggs, filter is 5 years old, dizzy cap was changed, not whole distributor, timing is to spec, I use seafoam occasionally in the tank. Haven't examined the injectors but they are original....

[68Datsun510]

No light, no smoke. The behavior only lasts a few seconds and has no repeatability... it behaves as if a single injector is a little lazy on startup.

[68Datsun510]

 

 

Yikes.

[q-tip]

Could be worse...

[68Datsun510]

I would expect these kind of plugs on a poor running oil burning too lean of jetted L-series engine but this is a modern fuel injected in line four that should not have lean out detonation issues which are very apparent on these plugs

[mhub91]

Are they the correct plugs? Heat range, etc?

[filthy forever]

vacuum leak? they can cause all kinds of problems

[68Datsun510]

ZFR5E-11 is factory spec.

[q-tip]

Oooo, what filthy said

[68Datsun510]

Vacuum leak, i would expect that from older engines... but this is 100% stock... Only think I can think of is from the brake booster line or maybe BPT valve...