rough idle

SURGING IDLE / NO IDLE CHECKLIST FOR 1999–2004 MUSTANG GT (4.6L 2V) This is a work in progress. Please run this checklist when it is applicable to you and provide feedback to help improve it. Feel free to comment with corrections or suggestions or diagrams or pinouts that you think might be...

This is a work in progress. Please run this checklist when it is applicable to you and provide feedback to help improve it. Feel free to comment with corrections or suggestions or diagrams or pinouts that you think might be useful. SURGING IDLE / NO IDLE CHECKLIST FOR 1996–1998 MUSTANG GT...

I’ll try and keep it short. I recently put long tube headers in, EGR delete since I found it a pain to attempt to attach it to the headers. I ran it just off the headers for a week with o2 sensors unplugged until I got a mid pipe for it. Within this time it ran completely fine, no issues. Before...

I bought this car with all the go-fast parts installed by a shop from the previous owner in Pennsylvania. When I bought it, it ran great with no idle or other misfire or rough idle issues. I moved back home to California and needed the car to pass smog certifications. I had to do the...

I am at my wits end, I have replaced near every sensor I can think of on my motor (‘89 5.0) and yet everytime I have to start the car cold it revs up and dies. It will restart immediately and then struggle for a few seconds before dying. Once it finally finds its idle and goes into gear (AOD) it...

I have a 2001 Mustang GT that turns over and runs very rough for a few seconds and then turns off. When I turn to start it back it will try but will not turn over. After waiting a little while it does the same start for a second rough and cuts off. When I give it gas it try’s to run really rough...

Okay, here I go again (on my own)..... I've recently (1.5 weeks ago) purchased this car, which my father owned up until 2019. The last owner put a cam (303 I think) in it and installed a Magnaflow exhaust (no catalytic convertors). My problem is it runs fine once it gets up to temp but...

Hey guys I've got 1995 5.0 GT. I've had it for 2 years and it's always had a bit of a rough idle, but it's gotten progressively worse. When I say rough idle I mean that when I start it the RPMs rev up to about 1200, then drop to 1000, then drop to about 750. It then proceeds to repeat this...

I'm new here but I have a 04 GT standard trans and my OEM plastic manifold broke at the heater hose fitting so I replaced it with a professional products typhoon intake manifold and I installed it and now the cars idle is very rough. Bouncing between 1200 rpms and 500 rpms. Thought it could be...

I just joined this resource and want to introduce myself. I own a 1965 red convertible 289 with a Holly 4 bbl and a 1973 yellow Mach 1. A couple of days ago I was driving my 1965 and all was well - nice trip around the "long block". A little later my daughter and her friends wanted me to take...

Hi, I have a 2015 salvaged coyote in a 67 mustang running on the control pack. Everything is up and running, but it seems to have a rough idle at start. The idle continues to be rough until I rev the engine and it settles down to normal at around 1000rpm for about 5 seconds, after 5 seconds...

So I recently got this manual 1995 GT with only 44k original miles, the car is great overall. BUT, I couldn't help but notice it has a rough idle (the engine shakes considerably but nothing too crazy) and can't maintain stable RPM's at idle (altough you can barely notice the difference, the...

I’ll make this as short as possible. Basically I plugged off all my unused vacuum ports on the “vacuum tree” and it bogs down like it wants to shut off once it’s warmed up. But it runs good at idle. But if I pull a couple of them off it doesn’t shut off but idles down a lot and runs worse. Any...

Hey guys, I drive a '98 mustang gt convertible, we swapped the motor out for an '03 v8. It has roughly 140,000 miles on the engine. In the past month it has started running real rough and my dad and I can't figure out the problem. When I first crank it and drive it it will be okay for about 10...

hey I'm new here and was wondering if anyone had a similar problem with their mustang like me. My mustang has been having a hard time starting lately and when it finally does run it idles at 1100 rpm and acts like the chokes on and also idles rough under 1500 rpm. If I give it gas while it's in...

Trying to troubleshoot 89 5.0L with rough idle when first started, down to the IAC valve. Pulled this valve and attempted to clean it, but looked clean already. My question is: how much travel does a correctly functioning IAC have? This is a basic two port spool valve but, while the spool in...

I have a 1990 GT convertible and the idle was surging after a few minutes of running so I did some research and replaced the IAC valve and when I started the car it ran great for about 10 minutes then it started to surge again so I replaced the TPS sensor as well and adjusted it to about .96 and...

I just bought a 2003 mustang gt three weeks ago and I have been chasing an electrical gremlin. the person before had spliced in a custom alarm system and I found the tail light fuse was blown. some of the things that I have noticed is when the car warms up the battery light comes on. had the...

So my 91 GT has been having some idling issues lately. Whenever I start the car it either stalls straight away if I dont step on the gas right away, or the RPMs will just jump around and it will not stay steady, and the eventually stall out. This past summer I took it on a pretty far road trip...

Hey guys, New member, i have used this site's knowledge in the past on many issues ( thanks for that), but I've come to a problem I need to reach out to you guys. I am on many different forums, bikes, motorcycles, chevy truck etc.. so let me start by saying thanks for looking at a new post by a...