First a bit of history on the car which is a '96 nissan maxima SE. We purchased the car years ago (6 or 7) from the original owner with 116,000 miles on it. He had said he hadn't done anything to the car (implying it was a great car). Definately no engine work. After I purchased it I did the standard maintance sparkplugs, fuel and air filter but no engine work other than a knock sensor.

Over the years the car seemed to start progressivly slower (Change was sublte over time so didn't really notice it happening). When I finally decided it was starting slow a few years ago I figured it was a bad starter or battery. Put a new battery in it and no change. New starter no change. Still started just seemed to take a fraction of a second longer so who cares. Drove it for a few years more and it seemed to take more cranking. When the engine was warm it began taking expecially long and some times 2 tries. Worried me expecially on trips but it did always start.

Ok that brings us to now. The car has just under 200,000 miles and the starting had gotten long enough that it was embarasing and very worry some. Time something had to be done about it for sure. I searched the forums and read various things but none seemed to work for me. I cleaned the battery connections, electrical connections checked grounds etc. I switched out the front crank sensor with another I had handy. Removed the belts to check for drag from accessories. Also checked the intake temp sensor and coolant temp sensor values using OBDII reader. Checked codes (none). Adjusted the throttle plate so it'd hold open more. Tried starting with a vacumme line open to see if more air would improve things. All no effect. I went through all the fuel pressure checks and it seemed that the fuel pressure was bleeding off too fast. So I was thinking fuel pump or leaky injectors. The fuel pressure did build quick and to the EXACT right amounts so the pump didn't make a lot of sense. Also if it were the pump switching it off then immediately (with no wait) restarting should have worked but it didn't.

So I removed the intake manifold and the injector rail. Pressurized it (by letting the fuel pump run) and looked for leaks. NO LEAKS period. Humm. So I cleaned the throttle body (with a little WD40 and a rag) some since it was out (none of the dirt looked to be blocking anything). Cleaned the IACV and associated valves. I also cleaned the inside of the runners just because it was off. However I personally didn't think that any of it was looking like the problem.

I replaced ALL the rubber fuel lines under the hood. (all the small coolant lines too but that won't change how it starts). Replaced the PVC valve and the fuel filter. Then when reassembling I sealed everything up really good (I used hylomar on top of the old gaskets but new gaskets would work too).

Conclusion:

After reassembly the car started RIGHT up. Shockingly quick. I expected a few turns since I had the fuel lines open. It's an AMAZING change. Just like it used to be 80,000 miles ago. I think it may have been one of the gaskets leaking. Could have been one of the things I cleaned. I don't know. Wish I did and could give more specifics as I am SURE someone else's car is doing the same thing. Oh and the nice thing is the whole fix cost me $45 (including the small dia coolant hose). Did take me about 8 hrs of work to remove the intake, clean things, replace lines and reinstall.

So if you've tried it all and no luck here's something else to try.

Car has been on the road a week and not once started slow. WHEW! Guess it's good for another 80K miles

Thaniel

 

Nice, I think I may do this one weekend, I could always use more excuses to take the car apart.

Plus. my starts are starting to scare me too...

 

At 256 Their Gettin Slow.

 

wish i knew how to do all the technical repairs

 

Cool. Mine is slow to start also. So if I read correctly, you placed the fuel lines, pcv valve, and fuel filter, being careful to seal everything on the intake during reassembly?

 

Yes (the upper intake manifold) and I removed the IACV and throttle body and cleaned (a little) and resealed them. I did also replace the rubber lines going to the PCV as they had hardened and were hard to remove.

It's very likely that it was only one of the things I did but at this point there is no way to tell. Just glad it is starting good again.

 

the best thing i did for my slow start issue is install a second battery in the boot (its really there to run my amps) but wow. first crank it will jump to life, litteraly within about 1/10th of turning the key the car is alive.

But i really don't see how an air leak is to blame for slow starting, for hard starting (turning but not catching) then yes, but an air leak / fuel leak shouldn't slow down the starter motor or the engine turning over quick enough.

 

I think we are getting caught up in symantics. To me the car is not "started" until the engine is running. The speed of the starter (cranking rpm) could be fast and a car could still not start (or be slow to start).

 

great ideas, i know what im doing this weekend

 

this DIY seems good for the fuel/coolant system but i dont see how any of those r & r's could fix a slow start.

 

not sure if its any help but i do know my friends problem with his blazer starting slow was due to a bad fuel pump but that could possiby be something or bad fuel lines

 

If you'd like to see for yourself just pull off a vac line, Say the one going to the brake booster, and try to crank it up.

It won't hurt any thing and it should start but you will see what can happen with extra air comming in that shouldn't be comming in.

 

I wish I could tell definitively which line was the problem. I have been battling a slow start since my TB/IACV cleanup, though my is not as bad. I did replace the fuel filter and all the water hose. I must have disturbed some thing (fuel line likely).

 

Did you reseal the TB/IACV good when you put them back on? Did the vac line to the TB get attached good again? What made you want to clean them?

 

I followed the FSM word by word, and am pretty sure they are done properly. Though, I did not do much to the fuel lines except for the fuel filter replacement which is why I leaning towards the fuel line problem.