MSPNP only idles well when super lean

I'm helping a friend with his 351 swapped 1991 Notch. The car is running a MSPNP, no MAF, no IAC.

He has an Autometer Pro-Comp Ultra lite Wideband that has a range of 0V=10AFR and 4V=17AFR.

The car starts up and idles but the AFR is 17 on the gauge and in Tuner Studio. If increase the VE table in the idle area once the AFR starts to get to 15ish the engine will begin to surge. I tried timing values between 12 and 23 degrees, but it does not help with the surging. The best idle I got was with the engine lean and timing values around 21 degrees.

When I begin to increase the VE table the engine idle speed increase, so I find myself using the throttle screw to bring it back down.

Why won't the car idle with an AFR close to stoich?


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2004 Mach 1 losing fuel pressure. Bad fuel pump?

Hello everyone,

Here’s my issue and some backstory on why I started troubleshooting. So my 2004 Mach 1 will never start the first try. But it will start the second. I’ve changed the battery, I needed to anyways so I’m not sweating over the battery change. The fuel pump is new. It’s a Walbro 255LPH. New doesn’t mean good. So in another thread I posted I was chasing down a crank no start on this car and finally fixed it. I changed the fuel pump in the process. That’s when the hard start issue came about. The car runs great and I love driving it. But I want to tackle the hard start. So I plugged in my fuel pressure gauge and in the run position, it reads 5 PSI. That’s criminally low lol. I can cycle the key from off to run about 4 times and it will build up to about 35 PSI which is its normal range of fuel pressure. But between 30-40 PSI, the fuel pressure will drop to 20 PSI within one minute. It will fall to 10 PSI and stabilize there and it will take about half an hour to drop any further. When the car is running, it is about 30-35 PSI at idle. As soon as you turn the car off, it again drops QUICKLY to 20 PSI, then down to 10 PSI and stops dropping. What do you guys think? Fuel pump? It seems weak to only generate 5 PSI in the first cycle of off to run and I’ve gathered there are check valves inside the fuel pump itself that can go bad. There are no fuel leaks I can see, as in no fuel on the ground, around the injectors, etc. I also suspect a leaking injector but I doubt the fuel pressure would fall THAT FAST if a injector was leaking. The fuel filter has been changed when I put the Walbro pump in a couple months ago. What do you guys think? Fuel pump? I’m open to all advice here. There are no check engine lights.

Progress Thread HP Turbo Notch build

Hello guys, Recently starting working on my 91 Notch with a older HP turbo kit, SVO heads and a Tremec 3550 transmission. The car is originally from Hawaii and spent some time in Vegas. When I originally bought it was sporting a weld drag pack since I have put on a mores streetable tire setup with a set of NT555RII on the back.

Recently I have had an issue with it blowing rear main seals, I have vented both valve covers to a catch can however it still keeps blowing them. The care is currently under the knife getting a terminator X installed and the motor gone through to find out what a possible issue is.

I don't know a whole lot about the history of the car other then it went 11.3 with an inexperienced driver.

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01 Mustang Overheating Radiator Fan not working.... Need Help

I have a 2001 Mustang 3.8L V6 base model manual transmission, about 3 months ago my car over heated, which caused my radiator to explode. I replaced the radiator, did a full flush, replaced the CHT sensor, the oil pressure sensor ( because my oil pressure gauge kept fluctuating from low to middle to high frequently), was running fine, then I got a P0305 code along with a P1285, I replaced the coil pack P 0305 hasn't come back but the P1285 is still present, I have noticed that the radiator fan isn't turning on at all but I have check the power to the fan itself and the fan works but just don't turn on which I think is causing the car to overheat causing the P1285 OBD Code. The CHT that I replaced is located on the back of then engine on the driver side right before the firewall.

I don't know what else to check but I need to figure this out ASAP.

Any advice would be greatly appreciated..

3000 rpm idle on start up

Recently purchased an 01 GT. When I bought it, it had a timing issue. I have replaced the Tensioner, chains, and guides and put it back together. When I Crunk it up for the first time, it revved at 4000rpm. Now any time I crank it, it goes to 3200 rpm and settles at 2600rpm. I don't leave it running long enough to warm up because I'm unsure of what may happen. I've cleaned the throttle body and checked all connections, sensors and vacuum lines. I can't seem to find any reason for it to do this. When researching it, there isn't many posts about a high rpm on startup, and what I have found, all describes the complete opposite of what mine is doing. Anyone experienced something similar to this? Looking for suggestions before I tear it down again.

Paint and Body Door jam rust

My 92 gt was a New York car so it’s got some surface rust all over but the only major structural rust is on the drivers side door jam. It’s definitely going to need to be cut out. Can anyone who has done this give me a ballpark of what it’s going to cost me to have a body shop fix this and what’s involved? I assume you just remove the fender panel and the door and then cut it and weld in some new metal. Any input will be much appreciated thanks.

looking for a hood

guys... kind of a bizarre question but is there any possibility on finding a retro fitted svo hood? im turbo 2.3 swapping my mustang and i would like to use the oem intercooler set up because i think the off center scoop looks kinda bad ass only problem is... i have an 1987 lx and im pretty sure my headlights would be an issue. dose anyone know of a company or a place to find what im looking for? heres a pic of the hood so you all know what im talkin about


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2004 Mustang GT with Keene Bell Supercharger making knocking or ticking noise, cant figure out if its rodknock or lifter or timing chain

I recently bought a 2004 Mustang GT with cobra heads, keene bell supercharger, cold air intake, exhaust, I was driving the other day and got on the gas just a little bit didn't over Rev it or anything just burned out aittle bit but immediately after I did that the car started running like :poo: and backfired a little bit started idling rough and then making this noise that I can't figure out what it is, here is a video of what it sounds like if anyone can help me.

Which car is better?

Good morning everyone, I'm currently saving up some money, and I was curious what do you guys say is the better long-term purchase? A 2014 Shelby GT500, or a newer mustang GT?

My plan for this purchase is to buy one and maintain it forever... I don't plan on ever selling the car once I have it. I also don't plan on taking it to any drag strips or anything like that, I would want this car to be my new daily driver to and from work (only about 20 miles a day), and take it on weekend cruises.

I also would add that while I do like the newer Shelby GT500's, they're a little out of my price range lol, so I'm not seriously considering those. As for now, I would say my limit would be under $50k.

I apologize if this has been discussed before!
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Questions about swapping a 2.3 Turbo motor out of a 88 Super Coupe into my 93 2.3NA Vert

Hello everyone! So I have been hunting for a turbo 2.3 motor for some time. I finally have a lead on one for a decent price. I have a T5 trany that needs to be rebuilt, but I don't really want to go through a manual swap for my daily. I'm not to familiar with these drivetrains... Would it be possible (realistically) to get that motor to work with my A4LD trany? I just had it rebuilt about 2 weeks ago and it cost a pretty penny. So I'm not eager to ditch it just yet. I'm not trying to do anything crazy with the new motor, I just want some more power than what I currently have. I'm doing research online about this, but I'd truly appreciate any additional info, tips, things to avoid, DOs & DON'Ts.

Thanks Guys! Allot of you have helped me through your comments in the past. I appreciate it.

Hi all. New here I have a 2001 Mustang Cobra. Idle issue and stalling

Went a bit overboard on the rebuild. Stage 3 cams,11to 1 compression ,2003 cyc heads, SCT MAF JTL cold air intake, 1inch spacer, BBK headers and more. Removed my BBK 65mm throttle body and it runes better. Had a remote tune done. Not to happy with it. It just stalls all the time after I bring the rpm up. Replaced the iAC, smoked for vacuum leaks passed. Not to happy with all I have spent over all. Any suggestions. Also I'm in central FL looking for a place to dyno tune my car. Most places I call say the car is to old.

96 Mustang GT Gauge Cluster Replacement with Unknown Aftermarket Speedhut Cluster (Information Needed)

I have a 96 GT Vert and the stock cluster works perfectly fine. However, the car came with this aftermarket cluster, and I know basically nothing about it. The previous owner said it was a cobra cluster but I can tell it isn't. I have no idea what year it is from, and can find no information on it online. It also has 3 wires coming out of it, which are not on the OEM one. I know it must be a pre-98 because it still has the mechanical odometer. I am pretty sure since my car is a 96, it doesn't have the chip that will trigger PATS, but would love confirmation on that. Also, I have no idea what the 3 wires coming out of it would go to. One wire bundle comes out of each of the 3 sections that you can pop out of the cluster.

I think it looks sick and would love to put it in (I already replaced the odo gear and put in LEDS since I had extras anyways), but I have no clue if it is compatible or not.

Any information about this cluster or advice on installing it would be welcome. Thanks


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