sweetbeats

Hey, everybody...been a long while since I've posted.

Our modded 2001 GT is alive and well (after a 2015 malicious near total-loss incident at the hand of a close and volatile family member...long story...), and lives a pampered life in the garage with only occasional outings.

One of my boys and I had it out the night before last and it is doing a funny thing...hoping for some pointers for where to begin the search for the culprit.

I'm getting a minor but consistent and rapid hesitation I think across the rev band...it feels like heavy wind buffeting the car when on the highway if you know what I mean...like, its not the engine cutting altogether, but like somebody rapidly flipping a switch on and off that takes noticeable power away. This causes me to have to press more on the accelerator in general than normal. The car is idling fine, and its not like it runs rough when at speed...its just like it noticeably loses power but in a rapid fluctuation. Every now and then I'm hearing what I think is a backfire, but it sounds like its down in the crossover pipe...like I hear it below my seat.

Any ideas?

sweetbeats

*bump*

Anybody?

Did I post this in the wrong forum?

Z28KLR

Being that it sounds like a misfire, I'd start with checking ignition related components.

Could be other things as well... Fouled injector(s), possibly a tuning issue (noticed you're f/i). If no check engine light on or flashing, since you have a blower if it were my car I would probably pay a tuner to take a look at things. Much cheaper than what could happen when something goes wrong on a power adder setup.

You posted in the right spot, just slow around here. Saw your thread a couple days ago but was hoping somebody more knowledgeable than myself might post something useful first.

sweetbeats

Thanks much for the reply.

Yeah, no check engine light is on. I do have an intermittent charging system light that comes on, but I was told that is a sign the alternator could stand to be replaced.

We probably drive it less than 800 miles a year these last several years. Barely has 60,000 on it.

Even with the hesitation issue it still pulls hard all the way through the rev range...

Does anybody know any way to find out who would be a good tuner to take it to? I really don't want to just take it to anybody. It would be awesome if there was somebody that knew these cars and had some familiarity with the MAFterburner and aftermarket intake charging systems. I'm near Portland, Oregon.

sweetbeats

The Mustang has been dormant for a couple months with the winter weather. Took it out today to see if it was still "hesitating" and it is...it's more like stumbling now. More backfiring into the resonator too. AND the front left brake is sticking. Geez when it rains it pours. I think I will take it to a shop here in town that looked at it before I was involved with it. Hopefully it's nothing serious. It started doing it after a great stoplight drag race with another built modular Mustang.

sweetbeats

Just wanted to follow up. The problem turns out to be a coolant leak that is getting into a connector. I'll post more when I know more as far as where coolant is leaking from and on to what it is leaking.

sweetbeats

Cooling system pressure test at 25lbs didn't reveal any leaks, but the back two spark plug wells were flooded. I'm pretty sure the plastic coolant hose nipple on the Dorman intake manifold somebody put on the car is cracked and leaking under pressure when the system is up to temp. It's been my goal to get the proper Ford Racing PI manifold on the car.

Is this about the best street price for one?

https://lmr.com/item/M9424P46/999-04...res-Lrs-10153A

EDIT

Just picked it up. It is still missing and backfiring. The rear spark plug well on the passenger side was full of coolant, and the next one toward the front didn't have coolant in it but there was rust dust and corrosion. So it's the two rear-most spark plugs on the passenger side. The tech said it is possible one or both of the plugs are damaged from the misfiring which is why it's still misfiring even with the coolant being blown out. The coolant hose goes right over that passenger rear spark plug boot, the hose that attaches to the plastic coolant nipple on the intake manifold. In addition, the next spark plug boot toward the front is cracked at the connector. Wondering if I shouldn't just replace all of those. Is there anything particular I should look for as far as a product if I did want to go forward and replace them along with putting in a new intake manifold?

WJL

A Dorman with a Vortech ???

Most times coolant is in the last two plug wells on the right side its from a cracked manifold or the heater hoses, your "tech didn't pull the plugs while he was there?

sweetbeats

Yes, Dorman with a Stage II Vortech.

I verified it is Dorman garbage and it's now in my very short list to get a proper Ford Racing PI manifold in there.

I'm also strongly considering getting new spark plug coil/boots on all 8 cylinders along with the new plugs.

The tech didn't pull plugs because I just paid the flat $80 diagnostic fee to tell me what was wrong. We are way short on money due to family emergency.

Thanks much for the supporting information about those two spark plug wells and the coolant coming from the manifold being a typical cause.

WJL

Well at least you know whats wrong, not that tough of a job to replace the manifold.