| ||
Visit MustangSteve's web site to view some of my work and find details for: FYIFORD Contributors' PICTURES - Power Brake Retrofit Kits for 65-66 Stangs - Classic Mustang FAQ's by MustangSteve - How to wire in a Duraspark Ignition - Mustang Ride Height Pictures and Descriptions - Steel Bushings to fit Granada Spindles to Mustang Tie Rods - Visit my EBAY store MustangSteve Performance - How to Install Granada Disc Brakes MustangSteve's Disc Brake Swap Page - FYIFORD Acronyms for guide to all the acronyms used on this page - FYIFORD Important information and upcoming events |
1 of 1
Offline
Hello Hello
We are having issues with our 1988 Ford mustang 5.0 LX.
Under acceleration it has some hesitation and it feels like a bit lack on the power too.
The idle is also a bit funny it rises in rpm and falls in rpm.
Have any of you experinced a similar problem with your cars?.
I have changed the spark plugs and the fuel filter on the car.
The car have not been used for several years.
So if you have any good leads on this subject and some hint where to look. Some help would be much appriciated.
Best regards Olling
Offline
This sounds like a fuel problem to me
If the car sat for awhile, I'd suspect bad gas and possibly clogged injectors (If EFI) or clogged carb? You might try something simple like injector cleaner. If not you may have to clean old gas out of tank put fresh fuel in and possible clean carb or replace injectors depending on what the car has!
Offline
I agree with Terry, but suggest to first dropping the tank washing it out then putting in a new pump and screen (rock auto have good prices on these) and a new inline filter, beleive me it will save a lot of headaches latter on, just confirm you get the right pump they do have different output pressures.
Last edited by bulletbirdman (12/28/2013 8:04 AM)
Offline
Is the car stock or has it been modded?
I'd like to know if it is still a stock EFI system.
Offline
EGR, PCV, and vac. line leaks are some things to consider/suspect on a 25 year old FI system and all have an impact on idle and driveability as well.
Offline
Hey
The car has the stock fuel injection system it was born with.
Olling
Offline
Go down to advance, auto zone etc and get a fuel pressure test gauge that will fit on your fuel rail its probably surging due to trash clogging Pump/pickup screen, check it against the manual for the car if you don't have a manual now is the time to buy one.
Offline
bulletbirdman wrote:
Go down to advance, auto zone etc and get a fuel pressure test gauge that will fit on your fuel rail its probably surging due to trash clogging Pump/pickup screen, check it against the manual for the car if you don't have a manual now is the time to buy one.
Oh by the way check your exhaust after a test run of a couple miles if you are leaning out it will cause excessive heating of the cat. converters I mean glowing cherry red.
Offline
Simple and cheap stuff first... Reach under the upper intake where the vacuum lines connect to the bottom of it. Be sure they are all attached and any rubber caps are not split from age.
But I agree with the others it does sound fuel related. Fresh tank of gas is main thing... then fuel pressure.
Offline
Olling wrote:
Under acceleration it has some hesitation and it feels like a bit lack on the power too.
The idle is also a bit funny it rises in rpm and falls in rpm.
Do you have an EECIV code reader available? I'd start by looking for some sort of EFI issue, and retrieving codes is a good place to start. Check this listing:
This guy has 12 of them brand new. Can't beat that price either. I have the exact same reader.
EDIT: He wants $16 to ship though. I'd check other listings for better price/shipping total.
EDIT 2: Here is one shipped free:
John
Last edited by John (12/28/2013 2:02 PM)
Offline
most of the parts store will pull the codes especially if they think they can sell you the parts to fix! and rightfully you should buy from them if they pull the codes.
Offline
Yeah they'll pull them but thet won't reset them.
Offline
My first guess would be the idle speed control. When they go out you get a wavy idle and it can even cause a poor throttle response at part throttle. Replacing mine did wonders.
Offline
Oiling,
As MS stated, start with simple and cheap first.
-pull the top off your air cleaner box and make sure, Ben and Willard haven't established a same sex, co-habitation rodent condo in there.
Those two dudes have a sweet tooth and fancy black licorice but, they tend to confuse it with rubber vaccum lines....check them really well. The line MS pointed out is notorious to dry rot.....and rodent teeth sharpening.
-next, purchase a can of CRC MAF sensor cleaner from the parts store ($6.99) then, access your MAF and spray it/clean it really well. It'll dry quickly so you should have it back together to test in no time. Do not use any other kind of clearner for this procedure and don't touch the MAF wire. There should also be a screen in the MAF, make sure there' s no foreign matter on the screen (ie: WIllard turds) if there is, spray it clean.
On my 90 GT, I had an idle surge issue plus a throttle response hesitation. When I finally cleaned the MAF the issue disappeared. This "could" be your issues as well. If not, we'll go to the next step
If you decide to follow this suggestion, post your results.
I would also dump a bottle of Techtron Fuel Injection cleaner or a can of Sea Foam in the tank with that fresh corn blended gasoline.
Hope this helps..........
Last edited by josh-kebob (12/28/2013 9:27 PM)
Offline
No MAF on an 88. They were speed density...
Offline
Olling wrote:
Hello Hello
We are having issues with our 1988 Ford mustang 5.0 LX.
Under acceleration it has some hesitation and it feels like a bit lack on the power too.
The idle is also a bit funny it rises in rpm and falls in rpm.
Have any of you experinced a similar problem with your cars?.
I have changed the spark plugs and the fuel filter on the car.
The car have not been used for several years.
So if you have any good leads on this subject and some hint where to look. Some help would be much appriciated.
Best regards Olling
I would start with the vacuum lines. There's alot of them. Only takes one to be cracked to cause a lopey idle and poor acceleration. As they age they get hard and brittle, and lose thier flexibility and eventually break. There's a 5 port vacuum tee bolted to the firewall. One is the source vacuum coming from the intake, and the rest supply vacuum to the AC, the emissions solenoids, the egr, the brake booster, and one is extra and blocked off. Under the intake, there is another vacuum tree, one branch of the tree is fuel pressure regulator, one branch to the vacuum tee on firewall, and another separate vacuum line to the pcv valve.
Offline
MS, good catch.....my bad on the MAF.................getting old stinks.......
Offline
josh-kebob wrote:
MS, good catch.....my bad on the MAF.................getting old stinks.......
anyone catch your AC DC tag line already? TNT
Offline
Just you Mark......when you drive about 500 miles from OKC back to Houston, you have plenty of opportunity to listen to tunes......some get stuck in your head too!!!!!!!
1 of 1
REMEMBER!!! When posting a question about your Mustang or other Ford on this forum, BE SURE to tell us what it is, what year, engine, etc so we have enough information to go on. |