Hard to start 99 4.0 sohc

[DayDayBr549]

got this 4.0 1999 explorer it turns over way too much before it cranks . I have cleaned the mas sensor , cleaned the whole intake system with sea foam , I have replaced a bad iac valve with a new one . There are no vacuumed leaks . I bought it not long ago and noticed the temp guage wasn’t going up unless I was running in traffic so I replaced the thermostat . This alone improves my gas mileage and it fixed the high idle I had been chasing since day one . It’s more responsive now too. I couldn’t expect it to run much better than it does now . It’s just hard to start up cold or hot in all conditions. It shouldn’t be this hard to start , it’s never failed to start , I smell no fuel l, it fires up and I see nothing in my exhaust but clean air , no blue or white smoke, it has 170k miles plus but seems to run out over all too good to shoot down my compression at this point .Any suggestions ? Ps no lights or codes on . Thank you guys for you taking the time to help!

 

[MrQ]

Check your fuel pressure should be about 60 PSI idling. Try cycling your your key two or three times before starting to see if the fuel pump is not priming the system enough. If so check the fuel filter first.

 

[donalds]

May want to take a look at the ecu temperature sensor

 

[koda2000]

I suspect it's time to replace your fuel pump. As suggested, check the fuel pressure at the fuel rail.

I recommend Bosch fuel pump (PN 69128 should be right for your '99) $40-$50 for fuel pump kit only on eBay. You'll also need a new strainer sock and fuel filter. I've installed at least half a dozen of these and they've all worked perfectly.

NEW Bosch Electric Fuel Pump Kit 69128 Ford F150 E150 Contour Explorer 1988-2004 28851791281 | eBay

 

[donalds]

I did not even think fuel pump duhh.

 

[DayDayBr549]

Check your fuel pressure should be about 60 PSI idling. Try cycling your your key two or three times before starting to see if the fuel pump is not priming the system enough. If so check the fuel filter first.

Awesome , I wish I could claim that lol , it just didn’t cross my mind , I just recently sold a 98 ranger and prior to selling it I had a nightmare with that pump , it was within the time that ford decided to go with a “fuel returnless pump” I was sold the pump that has the pressure regulator on the fuel rail and a return line for the fuel , one I needed had the pressure regulator in the tank attached to the unit with the pump , fuel guage sending unit pressure reg , all three on this unit , that was a bad but learning experience for me ! It actually had the symptoms that was corrected by accident when I got the right pump and installed it I nothiced it started a lot faster as in time spinning over before it fired off . For what it’s worth you guys that aren’t familiar with this pump in 98 , it’s interesting and also educational . I was advised ford changed it again after a short time of 2 or 3 years , the old return line types were replaced by the returnless pump systems to stop the odor of fuel after sitting hot awhile and restarted . They say the injectors were seeping a lilnfuel to cause this smell , so ford used another system that increased the pressure to correct that , don’t know if it survived or not , thanks a lot for yalls help I will get back and let ya know what I find with my f pressure

 

[974X4BLACKSPORT]

Ford, like many automakers, switched to a "return-less" fuel system solely that it consists of fewer parts, fewer parts increases profits, like many auto manufactures, Ford is in the "money" making business, not "car" making business.

 

[koda2000]

In my experience the return-less style fuel pumps start having problems in between about 170K-200K with intermittent long cranks and/or no starts. These issues usually tend to start showing up during cold weather. Apparently the brushes in the pump motors wear down and/or the springs holding them against the armature weaken and then the pump will work sometimes but not others.

My '01 EB 5.0L had an intermittent issue for several years with no starts/long cranks but only when warm. After 3-4 years of this it finally wouldn't start at all during the coldest winter days. New pump solved the problem. I've had to replace the fuel pumps in all my Explorers/Mountaineers, all between 170K-200K. The first one I did I bought an POS AirTex pump that only lasted 10k. After that I switched to the Bosch pumps.

 

[DayDayBr549]

I suspect it's time to replace your fuel pump. As suggested, check the fuel pressure at the fuel rail.

I recommend Bosch fuel pump (PN 69128 should be right for your '99) $40-$50 for fuel pump kit only on eBay. You'll also need a new strainer sock and fuel filter. I've installed at least half a dozen of these and they've all worked perfectly.

NEW Bosch Electric Fuel Pump Kit 69128 Ford F150 E150 Contour Explorer 1988-2004 28851791281 | eBay

In my experience the return-less style fuel pumps start having problems in between about 170K-200K with intermittent long cranks and/or no starts. These issues usually tend to start showing up during cold weather. Apparently the brushes in the pump motors wear down and/or the springs holding them against the armature weaken and then the pump will work sometimes but not others.

My '01 EB 5.0L had an intermittent issue for several years with no starts/long cranks but only when warm. After 3-4 years of this it finally wouldn't start at all during the coldest winter days. New pump solved the problem. I've had to replace the fuel pumps in all my Explorers/Mountaineers, all between 170K-200K. The first one I did I bought an POS AirTex pump that only lasted 10k. After that I switched to the Bosch pumps.

Check your fuel pressure should be about 60 PSI idling. Try cycling your your key two or three times before starting to see if the fuel pump is not priming the system enough. If so check the fuel filter first.

Me q’ thank you for the

 

[DayDayBr549]

Thanx for the help guys! I have not repaired the suv yet . But now atleast I know it’s the pump or the filter . That’s because you guys didn’t waste no time nailing it! If I cycle the ingnition about two times ‘ it’s a sure fast easy start every time ! I will be back when I get off my lazy side and fix it . Again thanx!

 

[410Fortune]

I agree long crank could be fuel PSI related.
It is also time to consider replacing your intake plenum O rings
There is not a SOHC engine on the planet from the 90's that does not need new intake plenum O rings...they dry up and shrink and leave you with intake leaks, especially when cold.
With a flashlight look at the area where the plastic intake meets the metal engine, is there an accumulation of dust/dirt/oil around there? Its getting sucked into your engine........

 

[donalds]

There is not a SOHC engine on the planet from the 90's that does not need new intake plenum O rings...they dry up and shrink and leave you with intake leaks, especially when cold.

Ant that the truth
I went to get a set of oem upper and lower o rings
The ford ones were kinda hard
So I went to buy the Felpro o rings
Much softer and all around better product