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Harder cold starts

DRanger024

Member
Joined
October 2, 2010
Messages
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City, State
Wisco
Year, Model & Trim Level
'02 Ranger XLT 4x4
Alright guys (and gals?), I have a ‘99 XLS 4.0 OHV that for some reason cranks over a little longer on cold starts after I changed the spark plugs/wires. After it’s warmed up, it starts like normal every time. Once it sits long enough to cool down, the cycle repeats. I’ve searched and searched the forums and google for any clues as to what could be the issue to no avail.
When I bought this thing in spring of 2017, the young guy I bought it from had the bank 2 plugs out because he believed it had blown the cylinder 6 plug out of the head. I reinstalled all plugs(cyl 6 threaded in and tightened up just fine) and fired it up to drive it and make sure it ran through the gears. It ran very rough, check engine and abs lights came on. I bought it anyways as he had bought an ‘04 and wanted the money for Tech school. Later that day after I had trailered it home and got some good gas in it, I plugged my scan tool in to be greeted by a whopping 17 DTC’s! Two of which were cylinders 4 and 5 misfires. The plugs were fouled with oil/fuel on these cylinders from a combination of leaking valve covers and not firing. This is where the copper plugs come into play not wanting to spend too much cash on something that may have larger underlying issues.
Needless to say, put the copper plugs in and it ran great up until it got cold out and the fuel pump pooped the bed. Replaced the pump/strainer and filter and it ran great until the plug/wire change to autolite platinum plugs and autolite premium wires. It fires up after about 4-5 seconds of cranking and idles a little rough. Idle cleared up after a few seconds and it ran like a top, no misses and very smooth. At this point I dismissed the long crank at first startup. Happy with the job done and the drivers side wires routed how they were from the factory, I dropped the hood and parked it outside. Ever since, it has started hard cold. It doesn’t matter how many times I cycle the key before I turn it over. It doesn’t matter if it’s -14F outside or 30F.

In the last couple months I’ve done/replaced;

Cam synchronizer and sensor
-reason: death squeak from original synchro
-September ‘17

Thermostat and radiator cap
-reason: cap was leaking
-Early December ‘17

Fuel pump/strainer and filter
-reason: pump died, might as well do it right
-Early December ‘17

PCV valve and vacuum line inspection/cleaned MAF
-reason: diagnosing high fuel trim values/poor MPG and P0171/P0174 DTC’s
-late December ‘17 single digit temps

Spark plugs and wires
-reason: had put copper core plugs in when I bought it in spring of 2017 for diagnostic reasons(cheaper) and it had the original wires in it from 1999
-late December 2017. This is where the hard cold start issue started

Intake plenum/throttle body gaskets and injector manifold gasket, checked fuel pressure
-reason: high fuel trims, P0171/P0174 all other possible causes eliminated - problem solved, fuel pressure reads above 60 psi and doesn’t bleed down
-01/05/2018

I was hoping the plenum leak was part of the reason it was starting hard. Fixed plenum and still having hard start/long cranking on cold starting. I’m completely baffled as to how a simple plug/wire change could do this. I have yet to try swapping back to the old plugs then old wires. Any thoughts or ideas would be greatly appreciated.

Thanks, Rick
 



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Anyone?
 






Coolant temp sensor? (the sensor not gauge sender).
 






I do not see any mention of battery. I feel like I'm in the twilight zone if there is a cold start issue and no mention of battery.
 






I do not see any mention of battery. I feel like I'm in the twilight zone if there is a cold start issue and no mention of battery.

OP starts by saying. "cranks longer on cold start, starts fine when warm". What would this have to do with the battery?

I wish there was a clear meaning of the word "cranks", to me it means the engine turns over but doesn't actually start running. Some people will say their engine doesn't crank and they mean it doesn't start, others mean the engine wont even turn over when the key is turned to START. Always confusing.
 






^ They make less current when it's cold. The last 1 - 2 years I had my old battery it cranked longer on cold starts but started fine warm, whether the temperature outside was warmish (for winter) or it had ran in the last few hours to have a little more charge in it and slightly warmed engine.

I mean below about 25F in winter, barely started at 15F and had little chance of starting below 10F without a jump. It was rare that I had a need to start it at that temperature as here that only happens in the middle of the night in winter and it wasn't my daily driver so I waited longer than I should have to replace the battery.

Got a new battery last fall and tested it a week ago, starts at -5F now (hasn't been colder than that here).
 






^ They make less current when it's cold. The last 1 - 2 years I had my old battery it cranked longer on cold starts but started fine warm, whether the temperature outside was warm or it had ran in the last few hours to have a little more charge in it and slightly warmed engine.

I mean below about 25F in winter, barely started at 15F and had little chance of starting below 10F without a jump. It was rare that I had a need to start it at that temperature as here that only happens in the middle of the night in winter and it wasn't my daily driver so I waited longer than I should have to replace the battery.

Got a new battery last fall and tested it a week ago, starts at -5F now (hasn't been colder than that here).

The OP never mentioned that it cranks slowly when cold, just that it's slow to start when the engine is cold, but okay. Often posters don't tell the whole story when they describe an issue they're having and it ends up being a game of 20 questions to gain a real understanding of their problem. I just go on what I read in their query. If they're leaving out pertinent info, I'm not inclined to waste a bunch of my time playing detective. Maybe that's just me. I didn't see this post as a battery related problem, but it's possible I guess.
 






The battery is less than 2 years old and came out of my Ranger. It doesn’t spin any slower than it does when it’s 80 degrees unless we get down to temps around or below zero. It will start after let’s say six revolutions instead of the normal one and a half. I’m really stumped by this. I’ve done plugs and wires, distributors, coils on everything I’ve ever owned and never once had a problem like this.
 






The battery is less than 2 years old and came out of my Ranger. It doesn’t spin any slower than it does when it’s 80 degrees unless we get down to temps around or below zero. It will start after let’s say six revolutions instead of the normal one and a half. I’m really stumped by this. I’ve done plugs and wires, distributors, coils on everything I’ve ever owned and never once had a problem like this.

That's why I was thinking maybe the CTS was not giving the PCM the correct information to modify the injector pulse width. It's kind of like a choke. There's also an air temp sensor, located near the MAF sensor, which monitors incoming air temp (I assume to do a similar thing). I see no reason why installing new plugs, wires (and whatever else you listed) should be effecting the cold starting.

BTW - I wasn't suggesting that you didn't give enough info in your original post. You provided plenty of data.
 






Thanks koda, I just wanted to clarify for everyone.

I'll have to double check coolant temp data before I start it next time. I suppose it's possible its reading high when the engine is cold and not dumping enough fuel. I had one of them unplugged at one point for some reason or another. IAT is reading within a couple degrees of what my overhead console reads and that has proven to be extremely accurate against a mercury thermometer. I still have the old plugs and wires and will most likely try swapping them around this weekend to rule that out.
 






The OP never mentioned that it cranks slowly when cold, just that it's slow to start when the engine is cold, but okay. Often posters don't tell the whole story when they describe an issue they're having and it ends up being a game of 20 questions to gain a real understanding of their problem. I just go on what I read in their query. If they're leaving out pertinent info, I'm not inclined to waste a bunch of my time playing detective. Maybe that's just me. I didn't see this post as a battery related problem, but it's possible I guess.
What led me down this tangent is that with my old battery, one of the cells was weak. It would still crank nearly the same, a little slower in cold but I expected that. It also read about the right voltage till an attempt at starting till near the end when I pulled the vent caps off and checked cell-to-cell voltages.

In other words in retrospect it might have been cranking a bit slower than normal for quite a while even in warmer weather but, maybe due to new plugs and wires, still managed to start reasonable well until very cold, wasn't acting like a nearly drained to dead battery that cranked slower and slower.

Instead it would do as DRanger described, "fires up after about 4-5 seconds of cranking and idles a little rough. Idle cleared up after a few seconds and it ran like a top, no misses and very smooth.", except as the problem got worse, it ran rough longer.

This made me wonder less about the temp sensors, if they're not providing needed data then what changes from the first few seconds started to seconds later, not enough time to change the temperature? I know on mine that the engine stays in a high idle due to very low temperature a lot longer than that, but it's not the OHV engine.

I'm less doubtful of the battery due to the statement "The battery is less than 2 years old and came out of my Ranger. It doesn’t spin any slower than it does when it’s 80 degrees unless we get down to temps around or below zero".
 






I did notice last time I hooked my scan tool up for a cold start that it doesn’t stay in open loop very long. Maybe 10-15 seconds. That seems a little odd to me. I have a late ‘90’s Dodge pickup that stays in open loop until the coolant reaches about 160 degrees. That one runs like garbage until that point though. My Explorer, once started, always runs like a top.
I do have a brand new battery here that I can drop in just to be sure.
I’ve also noticed that the MAF reads .01 lb/min with KOEO. I’m not very suspect of it because it’s clean as a whistle and worked/works fine. When switched to metric it reads between 3.8 and 4.1 g/min at hot idle. Target is supposedly 4.0 g/min.
Another thought I had was the possibility of catalytic converters starting to plug up. Ocaissonally it feels low on power and the cats ting rather loudly when cooling down. A wide open run usually clears that up. I know the guy I bought it from drove it for a while with the dead plugs so I’m sure they were either getting doused with raw fuel or a high volume of unburned gas fumes. Looking at those will have to wait as I haven’t had time to draw new flanges and burn them out. The old ones are still sealing but rusted to the point that the bolts are unrecognizable.
 






Your Explorer has heated O2 sensors. Your 90's Chrysler probably does not.
 






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