idle issue

First time poster here looking for some advice where to look next. I've tried a bunch of things but no luck maybe someone here has a good technique to try. So run down on car. 94 cobra, afr 185cc heads, f303 cam set straight up, edelbrock rpm2 intake with spacer for clearence reasons, has a 70mm...

I have a 92 mustang 5.0 with some mods done. when cold started it has a rough idle unless I unplug the iac the rpm’s drop the way they should. it’ll drive fine for about 10 mins and then it’ll bog completely on its face past half throttle and will eventually die if you don’t pull over and let it...

I’ve been having this issue for 2 years. Hasn’t been drove because I can’t fix it. When I crank it up cold it’s fine, then when it drops to idle rmps it will dip to 200 rpm real fast and then back to 700 back and forth fast until it dies. When I rev it up, it will come back down to 1000 rpms and...

Few months ago I installed a mspnp2, along with GT40P heads and intake on my 95gt, idling has always been an issue but the startup creeps to around 3k and hangs there for 4-5 seconds before dropping down, this is only when the car has ran in the last couple hours, cold starts in the morning...

Hey Y’all, Never had an F.i Mustang. Just picked up an 86 GT vert. 88k miles. stock everything Took it home, installed headers back exhaust w/ cats 70mm tb(I know too big probably) Removed smog pump and sealed vacuum lines and holes in heads after the work was done, she was idling rough...

When I start the car, it surges on high idle only. Normal idle and driving is fine. Its a 1986 with a carb set up. Any ideas why it might be surging? I checked for vacuum leaks but couldn't find any issues. I've adjusted my carb and timing where it runs the best. Bad idle circuit maybe?

I got a 93 foxbody that I had a blown lower intake gasket on so I tore it apart and replaced that. After getting it back together I can’t get it to go past idle when starting it. I still got good fuel pressure at 40psi at idle. It’s got a Pro M ECU and wiring harness, been converted to coil on...

Hey guys, I own a 2002 automatic mustang gt with: flow master CAI flow master H pipe just had an engine swap done with a rebuilt 78mm bbk throttle body SCT/Bama tune I’ve had about 900 miles since rebuild. Originally when I got the Car back from the engine install it had the same problem, 2k...

1987 5.0 Mustang GT Foxbody So I recently got a car that had been sitting for a while probably for about 10 years. When turning on the car it shootclouds of gray smoke and smelled like gas. I changed the fuel injectors, fuel tank and fuel pump thinking it would fix the issue. When the car is...

I have a 86 GT, 5spd. Engine is a 5.0(302) with gt40 heads and intake. e303 cam and shorty headers with catless xpipe. I am running microsquirt from efisource and an aem xseries wideband. Engine starts and runs great up to operating temp. I have an electric fan that's controlled by the ecu and...

Greetings to all, Currently running the diyautotune MSPNP Gen 2 v1.2 on my 93 turbo stang with a standard 302/GT-40x heads/F-cam running with FRPP 42lb injectors. I initially, downloaded the base tune from DIY and have been tuning. So far, it idles and runs really good. The issue I'm having...

Hello all! I am having a huge headache with my car as of lately. So here’s the story: Ever since the winter, the car has been sputtering, misfiring, and just not running like the 5.0 I know. Ran codes: KOEO: 11 KOER: 12, 92 I have done SO MUCH testing, and replaced a BUNCH of parts that...

Started as a surging idle when the engine warmed up then after a year the idle rose to 2500-3000 rpm I replaced the IAC and now the idle is poor and the car stalls and check engine light is coming on. Thinking about tps next unless anyone can think of something else. I have never had any other...

So, my kid broke down in his 2002 mustang gt last night with a car that was free revving and hanging at over 3k rpms. I couldn’t fix it in the dark so I towed it home. I removed the throttle body TPS, , IAC, and MAF and cleaned thoroughly. I replaced the TPS, IAC, and MAF before I found the...