bogging and rough idle help!!!

[manaen]

So with my motor showing 70psi, is this a problem? I need to check the service ticket to see if that is what I was actually told.

70 psi is only bad if you have the 35psi system. The computer will not be able to adjust eh injector pulse enough to make up for the increase in pressure. Your truck will end up running extremely rich and probably smoke black, foul plugs, and get about 7 miles per gallon.


if you have the 62 psi system it is on the high side but within factory specs. The computer should be able to deal with the increased pressure by shortening the pulse width at the injectors. You need to make sure which system your truck has Gen2's are kinda fuzzy because there are years that have both systems available and I don't know how to tell without looking at the system.

 

[manaen]

If you were referring to me.... I think there has to be something wrong with the 30 psi if i have a new pump filter and regulator.. Especially something wrong with the fact that with the vacuum line unhooked it only rises to 35 and should be between 50 and 55....

when you tested fuel pressure was the engine off or running?

Did you perform a leak down test to see if you have any injector problems?

If the engine was off did you cycle the ignition a few times to completely prime the system?

 

[TheVarmit]

Joe Dirt....over the past year and a half I've had all the problems with my 1996 Explorer like you have, ie hard starting, runing rough, ideling rough and mine would shut off while driving. First time a year and half ago, I replaced, cleaned, polished everything mentioned in the above posts...it ran fine for a few weeks then started again. I had it towed and checked, was told it was the fuel pump. Mechanic repalced pump and every thing was fine for alomost 2 weeks, then the same problems. Same mechanic replaced the fuel pump again, he said the one he replaced a week and half earlier was defective. Everything was fine and dandy with my explorer for about 8 months, then same problems returned but was getting worse and worse and more frequent. Finally I'd had enough so I took it to a different mechanic, he said it was a bad fuel pump. He repalced the pump, ever since it's been perfect.

What this last mechanic said was the problem.....the other 2 fuel pumps installed by the first mechanic were the worst pumps you could buy. The brand is Airtex. He said he's seen a lot of them malfunction within a few months of installation. He installed a Bosch. I've googled Airtex and their pumps have very bad reviews. Airtex is sold by most parts places (PepBoys, AutoZone, O'Reillys) and they are the only pumps they usually have in stock. I also heard that NAPA stocks Airtex.

Not sure of the reviews on Bosch, but so far so good with my pump....I'll let all you know months down the line.

 

[joe doe]

thanks for the heads up .national auto also gave me the heads up on the airtex brand .said they had alot of issues with them and no longer carry them .they now offer a reman factory pump for about 225.00 ,its the whole assembly.
i,ll be going this way soon as i save up some funds.

 

[wickedrigs]

***update***

So since I have replaced the ICM, I have had no issues until yesterday. It was 105 here and was miserable.

I was nervous about the drive home (approximately a 35 minute commute) but tried to be confident that the replacement of the ICM had fixed the bogging and sputtering issues. I drove home doing the speed limit the entire way without any steep grades. Went to an appointment and let it idle for 20 minutes with the A/C running (thought that was going to make her crack). Still, no issues. About 8-9 miles later, I thought that the ambient air temperature had decreased and decided to drop the windows and open the sunroof....mistake. I had the A/C off for only about 3-5 minutes before turning it back on. When I turned it back on it was blowing hot air and then she immediately began to sputter and bog out.

I don't know if the A/C being turned off and then back on had anything to do with it or if it was just coincidental.

Another observation that I made was that the transmission seemed to totally disengage when the sputtering occurred and when the motor would get fuel or feel like working again it would slam the torque converter and would engage. Does everyone that this is happening to have and automatic? Could this actually be a transmission issue? Just some thoughts. I am trying to post as much information as possible in order to resolve these issues. I am beginning to feel that my little toy is totally unreliable during the summer months and hate that feeling.

 

[manaen]

If you turned the AC off again did the truck seem to run normal?

 

[joe doe]

sounds like your heading for a fuel pump replacement like myself .its the long run times that seem to do it for my explorer .like when i drive it for a few hours with the air on .then it starts acting up .really doesnt matter if the airs on or not because shutting it off once the bucking and stalling starts doesnt help at all.
i believe its the long run time and the fuel pump is heating up .

try this .....when it starts acting up like that go throw more gas in the tank(aka..fresh "cool" gas)if it now runs normal again (the gas has cooled the pump)then your headed for a fuel pump replacement.that seems to be my issue too.
i been putting it off but enventually it will fail altogether leaving me no choice. ]
i have near 139,000 miles and i see alot of others have had this same issue with fuel pumps around this mileage.

 

[wickedrigs]

If you turned the AC off again did the truck seem to run normal?

I forgot to state that. I did not turn the A/C back off because I was in "rush hour" traffic and began to panic and looking for a spot to pull over and hide. Instead I just mashed it to the floor and made for the house.

 

[wickedrigs]

....i have near 139,000 miles and i see alot of others have had this same issue with fuel pumps around this mileage.

The vehicle itself has 144,000 while the motor has around 40,000. So I would have to agree that my pump is equal to yours in mileage. I guess I will tackle the pump this weekend then....

 

[joe doe]

try the fresh cool gas trick to be sure .but at that mileage i,m sure it could use a new one .stay away from the "airtex" brand pumps ,they are junk.

 

[wickedrigs]

try the fresh cool gas trick to be sure .but at that mileage i,m sure it could use a new one .stay away from the "airtex" brand pumps ,they are junk.

I did some research on those pumps after your post and read some pretty bad reviews about them.

 

[wickedrigs]

UPDATE. Yesterday, I had some errands to run and it was only 95 degrees here. Everything was functioning properly and then it started. Went to the nearest gas station and filled her up and no problems. Looks like she is getting a new fuel pump. Thanks guys!

 

[joe doe]

still havent done mine .long runs is when mine acts up .i am trying to enjoy a small break from putting money in this thing...lol....

 

[safn1949]

still havent done mine .long runs is when mine acts up .i am trying to enjoy a small break from putting money in this thing...lol....

Keeps you off the streets when you spend money on your toys,I should know.I have put about $3000 in my 94 the past 2 years.I like that truck and have a good job(and no kids).

 

[Barngrover]

Try cleaning your MAP sensor with brake cleaner.Do not use carb cleaner. The sensor is in the air inlet tube between the air filter and throttle body.

 

[wickedrigs]

I purchased the MotorCraft fuel pump today. I did not want to got with the Airtex and they couldn't get any other pumps for a 1999 Sport that was made in the USA. They only had them for the Mexico made models. Any thoughts or input about this?

 

[joe doe]

that the dealers part?how much you pay?
i still havent done mine .probably wont until next year come spring .

 

[wickedrigs]

Purchased it at O'Reiley's....I have a commercial account there. Cost me about $215 with special order and shipping.

 

[joe doe]

update

at 150k now and still limping my pump along .it did act up again this year when we hit high 90 degree days .done it maybe twice this year .
just gonna run it until it fails .just local driving with it no rode trips so when it fails i will have it towed in and my insurance carrier will reimburse me the towing so its all good .

 

[ranger7ltr]

Motorcraft fuel pump was under $ 150 at Amazon...

Last spring it was going for like $134.00 with free shipping... I happened to find it and bought one and installed it... Even the string of 100+ F days here is Texas haven't phased it...

Unfortunately that pump is up to over $270 now...That is a real shame since it was sooooo much cheaper not that long ago...