Hi guys,
Having a hard start on my 2000 maxi when cold or 10+ min soak. Have to do a 2nd start cycle and then it starts and stabilizes and is fine.

Restarts fine on 1st try within 5 minutes of soaking. Runs good once started. Longer than 5mins and it's not happy.

No recent work other than BG44k fuel treatment and switched to premium about 1500 miles ago. I was using 87oct. Issue seemed to start not too long after BG44k but I have used a number of times before and zero issues.

Pulled off vac hoses on fuel regulator and dampener and both looked free of fuel.

Fuel filter is approx 9,000 miles old.

Thanks in advance for your ideas.

 

Bump. Any ideas? I have no codes, either.

 

i had a problem (no codes) when car's been sitting a while would start ok, then shut off the engine go to the store or something, get back in and try to start again, wont start, that or starts then rpms drop too low car dies. either i had to let it sit for a while to let it cool down or press on gas pedal to force rpms above 2000 so it wont die, once you get going seemed ok.
i got some throttle body cleaner and cleaned the throttle very well (make sure you get in there deep) also a good idea to completely disconnect the battery during this time, and problem fixed, ran beautifully after that.
i only use 87, as for treatment only use gumout 30001

 

I did have a slow idle issue in tbe past when not warmed up and I cleaned tb and it worked. Maybe this is same issue....will clean and see.

 

might try obvious stuff too, could be bad air or fuel filter, could ba spark plugs, have the battery tested, my neighbor's car would randomly die while driving, no codes, battery was new, tried everything, decided to swap the battery just to see, boom, problem solved, turns out it was a manufacturing defect...

 

I'm thinking spark plugs or try changing the engine coolant temperature sensor, ECU uses it as one of the main factors in controlling the fuel ratio, especially on cold starts.

 

The fuel pumps can leak down, lose prime. When its doing a long crank turn the key of then try again. If it starts right up thats a clue it may be the pump.

 

That does seem to help. But wouldn't a bad pump affect driving and power? Once running its good.

I guess I want to prove the pump or regulator or diaphragm before I go replacing parts and not sure how to do that.

I think I will cold start it and run 1 min and then restart and see what happens. Nothing will be warm yet and if it starts fine then might swap the pump.

 

Update: Started a cold engine today. Had to crank 2x like its been doing. Ran exactly 1 min. Shutoff and sar 30sec. Started fine.

Unsure about coolant temp sensors but 1 min won't even open the thermostat so that shouldn't have affected it imo. Maybe I'm wrong.

Leaning on fuel pump. It is original.

Any thoughts? Hoses on fpr and diaghram seemed dry.

 

try this:

 

I had similar hard starts after several minutes of heat soaking. It was the rubber air tube between the throttle body and MAF. It had developed hairline cracks from age and allowed air to bypass the MAF. Also make sure the connections are air tight. My 2000 has been starting perfect since.

 

I will have to spray carb fluid on hoses when cold engine and see if it affects things. This start could be many issues

 

I should mention the hairline cracks were in the folds of the air tube and difficult to see. As the engine is cranking with the starter engaged, the engine tends to move more and pulls on the folds of the air tube allowing air to sneak in the cracks past the MAF. My fix was the replacement of the air tube.

 

ok. Thanks. I cleaned the maf just to rule that out as well.

How did u find the crack? (Other than remove and inspect with a light)?

 

I think I may be also needing to check fuel pressure. Where do u guys tap into it?

Wondering if those kits with the T in them would work at the hose connection at the pump asm. I just don't know where to tie in a gage.

 

Yes that's correct if the pump was bad it wouldn't matter what conditions. The better word to use might be replacing the pump assembly. Which includes the check and pressure pressure valves, sending unit and pump. An all-in-one assembly. All the manufacturers did this. Not sure why. Makes it hard to test. Your best bet to do that if you want to is from under the seat. Tap into where it connects to the pump.

 

Rodent: My pressure and diphram valve is in engine bay. I have a 2000. Both vacuum lines look clear but I've read that they can leak internally as well and allow pressure drop and not show in vac line.

Still trying each potential thing but I will need to likely tap the fuel line. Can't I remove the line at the asm under the seat and easily hook the gage to that? One of the kits I saw online had a T and wondering if that fits. We don't have a test port from what I've read.

 

could have leaky injectors that are flooding the engine. how old are your spark plugs?

 

Plugs are ngk coppewoupdl are 24000 miles old.

I did wonder about an injector issue. It smells gassy when it starts but that could be from double the normal cranks. Seems if it were flooding it woud be even harder to start...maybe a clog but how can u easily find that without, what, pulling each one and inspecting?

 

AutoZone load tested and battery held 13v they said but his gizmo reported to replace the battery so volts are lower than optimal but seems to me it should not be my issue. Maybe a freak thing but seems it should be unrelated to my issue.

 

for me it was the idle control valve. i don't know if that was the reason but after replacing it it never did it again.

 

Still cant resolve this hard start.

Removed & cleaned TB.
Replaced cracked intake hose.

Pics below are after 5-7+ mins idling.



Checked audible noise w/ long screwdriver from front 3 injectors. All seemed identical.
Air temp sensor ohms checked ok.
Re-adjusted accel cable.

It's far worse now that the weather is cold. Maybe it would have gotten worse regardless, but I believe cold air is worse.

When I manually operate TB, I hear air suction from rear of motor. Maybe that's the way its always been but wondering if that's normal.

Will pull some plugs when car cools down and see if fouled.

Still struggling.

 

I got my money on the ECT. if the ECU doesn't know how cold the engine is it won't throw in that extra fuel for the cold start.

I remember when I had my 91 Nissan Stanza and I installed a button for the starter because the ignition switch would stick and eat up starters. the car had a KA24E that used a cold start injector. when I would start the car cold I would actually have to hold the key in the cranking position while pressing the starter button. the cold start injector only worked while cranking the car with the key and the start button being wired directly to the starter bypassed that. when the car was already warmed up I could just turn the key to the run position and press the starter button. but on a cold start it would just crank and crank until I put the key into the crank position while holding the starter button..

 

Uptown: You are referring to the coolant temp, correct?

Are you aware of a reliable test on the sensor? And would it be the sender or the sensor?

I took maxi to a shop a week ago....started perfectly for them. They couldn't duplicate issue. It sat outside as well in cooler weather.

I picked it up and it started fine 2x.

Now its struggling again.

I see the coolant sensor/sender are inexpensive. Tempted to just replace them both if I can't test for a failure.

 

Measure your water temp sensor resistance!

 

Good suggestion....and I did just that.
It was within spec I would say....the fsm had it based on a few temps and mine seemed to be relative to that.

 

I have 4th gen maxima. It had exactly same issue as yours, hard start when cold and hard start when warm. Once it got running, no issue.

I traced it back to throttle body and wax solenoid. It was not ECTS as many said. It was really close since both are related to coolant/temp. Warm/hot coolant going through TB makes wax expanding, moving plunger which pushes the butterfly open. This modifies A/F ratio mechanically.

In 4th gen, this is called IACV-FICD. Basically, FICD acts like small engine choke. You set choke when cold start and half/no choke if you want restart (warm). It was preset at factory and it is not supposed to be adjusted, but wax solenoid can be replaced. On mine, wax/coolant leaked, plunger seized and no longer moved TB cam follower correctly. The effect was no choke during cold start and half choke warm.

Your max is 2000, the TB is different than 4th gen ones, no more wax solenoid. Image on Ebay still shows coolant connection. You may check if your year TB still behaves same, causing your issue in similar way.

Good luck.

 

Thought you might be interested. I replaced the fuel pump today in the 2006 Altima that's having a hard to start after driving then sitting for 20 minutes. I cannot replicate the problem so it would appear the fuel pump fixed it. I went with a $55 eBay pump. In a few days when I'm comfortable with the new pump I'm going to take it apart and try to figure out what was causing the loss of prime only when it was warm. Good luck trying to fix your problem

 

There is a sentra in the family that had hard start between 10min and 1 hour soak but never an issue when cold. Perfect start unless during a a few minutes after a run. I replaced entire pump asm and its been fine.

Makes me think same issue on my maxi but symptoms are diff when cold.

My TB is clean and coolant lines are disconnected from it.

 

You may've caused your own issue.

 

i had this problem on my maxima, the culprit was the diaphragm that sits on the throttle body, the internal rubber part had a hole in it and would not increase the idle for cold start. easy way to check if it this is is either squeeze the small rubber hose or disconnect it from the diaphragm when engine is cold, then start it, if idle comes up and you dont need to keeep attemtping to start it, this could be the issue if not something vaccum related in the cold start cycle could be causing it.

 

...no...because I did that mod 3-4-5 years ago. Can't remember but its a long time ago.

 

Took it to a shop. It started PERFECT for them. No issue.

I picked it up from then and it started perfect for me too! Went to a store. Came back out and it was crappy starts again.

Learned also that if I "bump the starter" and turn off and then crank again its fine. Like it wants 2 cycles to be happy.

I really thought it was the FPR. Replaced it. Nope. Still a hard start.

Still think its fuel related just don't want to put in $100 pump for nothing like the regulator.

Ticks me off.

 

Wanted to update on this issue. Its been a while but I got it fixed. It was the fuel pump. FYI.

Thanks everyone for your replies.

 

Did you use OEM or aftermarket?