93 explorer sport starting issues

[SFCRangerDoc]

Update: I received my air temp sensor and coolant sensor in the mail today. after some cussing and all that they have been changed. The ambient air sensor was coated in what looked like varnish so that could be it. The coolant sensor was coated in green sludge so that could be it too. Needless to say I will now have to wait a day or two and try to start the car to see if changing those out did anything. Next on the list if these dont resolve it will be the MAF/TPS/IAC for good measure. I sort of went through the wires while doing this and all look good from what I can tell.

 

[natenkiki2004]

Don't replace the MAF/TPS/IAC just for good measure. Test them first. If you MUST try another, get them from a junkyard so you can quickly and cheaply eliminate them.

 

[SFCRangerDoc]

Update today: still hard starting..6-7 cranks. no CEL no nothing indicating a problem....onto the next batch of sensors and testing. Thanks for putting up with my updates guys! I appreciate the input.

Question: How long should fuel pressure hold on the rail. If i start the car and it sits at 30ish nicely, how long should I expect the pressure to stay before it bleeds off. I'm pondering an idea if i have a "slow" fuel injector leak it could be flooding the motor making it hard to start. or am i totally chasing down the wrong rabbit hole with that.

 

[natenkiki2004]

There's a fair amount of flow, you should notice it right away if there's a severe issue. The thing is, in our systems, the pump puts out way more fuel than the engine needs, the extra gets returned to the tank. You'd have to have severe pump issues in order to not keep the right pressure. I don't think a leaking injector would cause low pressure, even if it was stuck open. It would certainly cause drivability issues though.

If you're talking about how long it should hold the pressure sitting with the engine off, I don't think you'll find a straight answer. There should be SOME pressure overnight but there won't be 30PSI. Half hour after running the vehicle, it should hold pressure that long. I've not seen a spec for leak-down though so it's hard to say.

 

[SFCRangerDoc]

There's a fair amount of flow, you should notice it right away if there's a severe issue. The thing is, in our systems, the pump puts out way more fuel than the engine needs, the extra gets returned to the tank. You'd have to have severe pump issues in order to not keep the right pressure. I don't think a leaking injector would cause low pressure, even if it was stuck open. It would certainly cause drivability issues though.

If you're talking about how long it should hold the pressure sitting with the engine off, I don't think you'll find a straight answer. There should be SOME pressure overnight but there won't be 30PSI. Half hour after running the vehicle, it should hold pressure that long. I've not seen a spec for leak-down though so it's hard to say.

Yeah I was more referencing the bleed down after shut off. The car has no issues while driving etc. It holds 30 for a good long time so I guess it's not that. Just was chasing a thought.

 

[larrydd999]

Intermittent ignition coil or related wiring, perhaps?

 

[SFCRangerDoc]

Intermittent ignition coil or related wiring, perhaps?

I haven't pulled the coil yet, but I suppose that's not hard. All my spark plug wires are good (as far as I can tell). I'll pull it and inspect and report back.

 

[SFCRangerDoc]

Update:

I tested the coil pack and I'm getting strong spark while running on all 6 plugs so I think that is good. Unless its just not happy in the mornings/cold then I think I can rule it out. Theres no rust or grime or seepage around the coil pack at all.

I also performed a KOEO test and was getting 111 before the 6 second pause so that tells me that the CPU can't find anything wrong. However it was throwing some codes after the pause one of which is 157 which is the MAF voltage. Maybe i just need to suck it up and replace the MAF I think the next code read 122 maybe 121 (ill have to recheck) also has to do with the TPE being inconsistent with the MAF and/or voltage issues. Maybe I do just need to suck it up and replace those two sensors.

 

[SFCRangerDoc]

Update:

For those that may be following this post I apologize for not updating sooner. Replaced the TPS on the throttle body, no change. So I started changing out relays just to be sure I didn't have a bad relay for the fuel pump or ECU. Still no change. It's getting worse now that the days are getting cooler. I am begrudgingly going to order a fuel pump and drop the tank and replace it. Past that, I'm ready to drive the bleeping thing off a cliff and write it off as an insurance loss.

 

[xplorernewb]

my car will hard start every now and then as well, usually it will start up fine but run rough for a few seconds until i give it some throttle and it'll smoothen out during take off. been doing this for a while. maybe these 2 could be related, maybe not.. but i read somewhere, ill look for it later, there is a flaw inside the computer. it causes a miss fire under load. out of curiousity, you think the engine would be considered under load while starting? also, my temp spikes up to about 1/2 way on the gauge but levels out after the idle drops to normal. again maybe related, maybe not. maybe the flaw just got worse and causes more problems like what you're describing

 

[SFCRangerDoc]

my car will hard start every now and then as well, usually it will start up fine but run rough for a few seconds until i give it some throttle and it'll smoothen out during take off. been doing this for a while. maybe these 2 could be related, maybe not.. but i read somewhere, ill look for it later, there is a flaw inside the computer. it causes a miss fire under load. out of curiousity, you think the engine would be considered under load while starting? also, my temp spikes up to about 1/2 way on the gauge but levels out after the idle drops to normal. again maybe related, maybe not. maybe the flaw just got worse and causes more problems like what you're describing

It very well could be something regarding the computer...starting would definitely be a "load" i would think.

I just went out on lunch and tossed my fuel pressure gague on the engine. Had been sitting since 730am...it was at that time 11:30am. 0psi. (i had attempted to start the car at 730 am after sitting allnight). cranked the motor...no start. fuel pressue immeadiately jumped up to like 38psi upon cranking. Cranked for a good 10-15 seconds...no start...key off and then back to crank...cranked for another 5-7 seconds and it acted like it was going to catch. fuel pressure still up between 35-40psi. third crank 3-5 seconds the car started and fuel pressure dropped to about 32-33psi while ldling... This thing is maddening. Do i try swapping out the fuel pump even though it seems to be getting pressure?? I'll try to take a video next time

 

[xplorernewb]

try spraying Ether around the intake manifold while starting. if it fires up or tries to sooner than usual you have an intake leak. from my experience usually when a fuel pump goes bad it gives no warning, and these intakes are known for leaking (as all intakes are). 3 main things - air, fuel and ignition. if you have 2 out of 3 working, it wont run very well if at all. the cold weather could also affect this if it were an intake leak.

id try other things before replacing the fuel pump. just my opinion

 

[xplorernewb]

by the way did you check your cam position sensor? on my jeep, it got wet once and wouldnt start. maybe yours could be dirty...

 

[SFCRangerDoc]

by the way did you check your cam position sensor? on my jeep, it got wet once and wouldnt start. maybe yours could be dirty...

No sir, i haven't checked that out yet. I'll do that. And I'll try the starter fluid test too.

My dad has a 93 explorer 4x4 XLT that I may try to "borrow" the brains out of for a couple of days. Unless there's something majorly different between it and the 93 sport it could give me an idea if the ICM is going bad w/out having to front a bunch of money.

 

[SFCRangerDoc]

so uh, i think before i go any further the spark plugs need to be changed...my wife had said they had been done within the last 50k...yeaaaah no. I pulled only one plug and found dat gap...im going to replace all the plugs first before i go ANY further. I'm feeling rather stupid at the moment...im hoping this is all it is...

 

[xplorernewb]

yikes. might want to replace the wires too. stick with OEM, they're picky

 

[xplorernewb]

you should also compare plugs with one another. that'll tell you if it has a lean or rich mixture, aka too much fuel/too less oxygen or too much oxygen and not even fuel. worst case scenario some will be different, some white, some black.. that'll tell you if you have a leak somewhere.

 

[SFCRangerDoc]

Ok so, i have swapped out my spark plugs with NKG platinums and new bosch wires. All 6 of the old plugs were in excess of .080 gap but honestly all looked similar wear/burn so i think the motor is burning/running evenly. I'll know tomorrow morning if the hard start was related to the plugs /wires or not!

 

[2stroke]

That plug indicates it is running lean IMO. Fuel injected engines usually run lean, but that plug is bleach white, and the electrode is as well.

 

[SFCRangerDoc]

Update:

I still am having starting issues after changing the plugs and the wires

Runs great once I get her going...way more pep with the new plugs!

Decided to test the car during cranking with starter fluid. Mrs RangerDoc climbed in and cranked it a bunch and midway during the crank i hit it with some and it fired...ok so maybe i've got a fuel problem.

This weekend I swapped out the fuel filter...not too hard to do at all! Old filter was absolutely terrible. I cut it open and it looked like a used oil filter...it was packed with black sludge and before i cut it open i couldn't hardly even blow through it!!! I'm wondering if the sludge is hardening up over night and starving the motor for gas on startup. I'm letting the car sit for a day or two and will update later this week.

Past this, ive got only a handful of other things to change before im out of options: MAF hasnt been changed, computer hasn't been changed, nor has the fuel pump...