Hey guys, I could use some help figuring out a 94 pathy with a hard cold start. Runs fine and restarts easily once it's warm, but takes LOTS of cranking to get it to start when it's cold. Once it starts it doesn't take long to settle down and idle normally, but exhaust smells rich. I replaced a coolant sensor, pcv valve, and fuel filter and no change. Air filter is new, can't find any loose or leaky vacuum lines.
I bought this rig as a project for $350 with only 120k miles, super clean body and interior, but timing belt and accessories off the engine. I thought the engine may be bad but put it all back together - new water pump, and timing belt. Engine wouldn't turn over, but felt like it had compression cranking it by hand. Put in a starter and and engine started turning, but no fuel. Put in a junk yard fuel pump and voila, I'm running. Engine sounds good (nice and smooth with no misses), timing is on, 3 spark plugs are nice and brown, two were black but not fouled, and I didn't check the 6th one. Plan on changing plugs and wires in the future but don't really think that's my cold start problem...
Appreciate any suggestions anyone might have. Thanks!!
94 pathy - hard cold start
Re: 94 pathy - hard cold start (cnatsu1)
Want to clarify cold start for me is below 40 F. Home sick today and we're in the mid 40's and it started perfectly, with no white smoke or rich smell to the exhaust.
Also forgot to mention I'm not pulling any codes.
Also forgot to mention I'm not pulling any codes.
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Ron Burgundy
- Posts: 318
- Joined: Fri Jun 12, 2009 1:54 am
- Car: 1999.5 Nissan Pathfinder 3.3 LE
- Location: La Habra, CA
Re: 94 pathy - hard cold start (cnatsu1)
How's your battery?
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94 Gasfinder
- Posts: 18
- Joined: Tue Feb 23, 2010 1:25 pm
- Car: 1994 Pathfinder SE 4x4 (sold)
1997 D21 Hardbody 4x4
Re: 94 pathy - hard cold start (cnatsu1)
I have the same year truck with the 3.0 with 180,000 on it and I know that it starts pretty erratically. Some days it'll start fine, other days like today where its 35 F outside it turns over sluggishly. After letting it warm up and trying to start it again it'll turn over real fast, faster than normal, but only because the oil has thinned. I'm not really worried about my engine, but then again you have had yours ripped apart pretty good.
You mentioned that you put a starter in it, was it new, remanufactured, junk-yard, or the one that came with it? Also, does the exhaust smell rich right after cranking it for a while, or after it's settled to idle? You could try resetting the ECU and let it re-learn the proper AFR. This post should get you on the right track for the proper procedure.
If you try it, let me know how it works out for you as I've been meaning to try it on my truck.
You mentioned that you put a starter in it, was it new, remanufactured, junk-yard, or the one that came with it? Also, does the exhaust smell rich right after cranking it for a while, or after it's settled to idle? You could try resetting the ECU and let it re-learn the proper AFR. This post should get you on the right track for the proper procedure.
If you try it, let me know how it works out for you as I've been meaning to try it on my truck.
Re: 94 pathy - hard cold start (Ron Burgundy)
Thanks for the replies.
Battery is strong. I was cranking off and on for a couple of minutes in cold weather before it would start. Mid 40's again today and it started perfectly when I got home from work. It's supposed to cool off again in the next few days and I'm curious to see how it will start in the colder weather again.
Is there anything besides the coolant sensor that would affect cold starts??
I put in a remanufactured starter - probably should have gone for a better one.
Waiting on an anttenna adapter to finish putting in stereo/mp3 player. Next up is replacing the front cv axles and then an alignment.
I'd forgotten about relearning the ECU... Let you know if I try it.
Battery is strong. I was cranking off and on for a couple of minutes in cold weather before it would start. Mid 40's again today and it started perfectly when I got home from work. It's supposed to cool off again in the next few days and I'm curious to see how it will start in the colder weather again.
Is there anything besides the coolant sensor that would affect cold starts??
I put in a remanufactured starter - probably should have gone for a better one.
Waiting on an anttenna adapter to finish putting in stereo/mp3 player. Next up is replacing the front cv axles and then an alignment.
I'd forgotten about relearning the ECU... Let you know if I try it.
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Ron Burgundy
- Posts: 318
- Joined: Fri Jun 12, 2009 1:54 am
- Car: 1999.5 Nissan Pathfinder 3.3 LE
- Location: La Habra, CA
Re: 94 pathy - hard cold start (cnatsu1)
First result from google search: "hard to start when cold"
Original text found here: http://autos.yahoo.com/maintai....html
If your engine has a carburetor, the hard starting problem is most likely choke related. If the engine cranks normally and the spark plugs are not worn or dirty, the choke probably needs to be repaired or adjusted.
The choke may be set too rich or too lean. Either way can cause hard starting. Inside the choke housing is a bimetal spring that regulates the tension on the choke according to temperature. If this spring is broken, the choke will not operate. If the choke linkage is rusty or jammed with varnish deposits or dirt, it may stick or not operate smoothly. Cleaning with carburetor spray or solvent may help alleviate a sticking problem.
On older fuel injected engines, a separate "cold start" injector is used to spray additional fuel into the intake manifold when a cold engine is first started. If this injector is not working, the engine can be hard to start. The injector is controlled by a timer and relay, so if either of these components is defective it can prevent the cold start injector from doing its job, too.
If your engine cranks slowly, your cold starting problem is not fuel related, but may be due to a weak battery, loose or corroded battery cables, or a weak starter.
Check for obvious problems first. Remove, clean and inspect the battery cables (both ends). Then check battery charge and condition. (More information on the condition of your battery and battery recharging is available.) If the battery charge is low, recharging the battery may temporarily solve your problem. But there's a reason why your battery is low. You probably have a charging system problem that requires further diagnosis. (More information on alternators is also available.) If your battery is more than four or five years old, it is probably near the end of its service life and needs to be replaced. A "load test" will tell you if it still has sufficient cranking capacity to provide reliable cold starting.
Slow cranking during cold weather (below freezing) can also be caused by oil that is too thick. A high viscosity oil such as straight 30 or 40 weight oil in the crankcase can make an engine very difficult to crank when the temperature drops. Switching to a lighter multiviscosity oil such as 10W-30 or 10W-40 should solve this problem.
Original text found here: http://autos.yahoo.com/maintai....html
If your engine has a carburetor, the hard starting problem is most likely choke related. If the engine cranks normally and the spark plugs are not worn or dirty, the choke probably needs to be repaired or adjusted.
The choke may be set too rich or too lean. Either way can cause hard starting. Inside the choke housing is a bimetal spring that regulates the tension on the choke according to temperature. If this spring is broken, the choke will not operate. If the choke linkage is rusty or jammed with varnish deposits or dirt, it may stick or not operate smoothly. Cleaning with carburetor spray or solvent may help alleviate a sticking problem.
On older fuel injected engines, a separate "cold start" injector is used to spray additional fuel into the intake manifold when a cold engine is first started. If this injector is not working, the engine can be hard to start. The injector is controlled by a timer and relay, so if either of these components is defective it can prevent the cold start injector from doing its job, too.
If your engine cranks slowly, your cold starting problem is not fuel related, but may be due to a weak battery, loose or corroded battery cables, or a weak starter.
Check for obvious problems first. Remove, clean and inspect the battery cables (both ends). Then check battery charge and condition. (More information on the condition of your battery and battery recharging is available.) If the battery charge is low, recharging the battery may temporarily solve your problem. But there's a reason why your battery is low. You probably have a charging system problem that requires further diagnosis. (More information on alternators is also available.) If your battery is more than four or five years old, it is probably near the end of its service life and needs to be replaced. A "load test" will tell you if it still has sufficient cranking capacity to provide reliable cold starting.
Slow cranking during cold weather (below freezing) can also be caused by oil that is too thick. A high viscosity oil such as straight 30 or 40 weight oil in the crankcase can make an engine very difficult to crank when the temperature drops. Switching to a lighter multiviscosity oil such as 10W-30 or 10W-40 should solve this problem.