View Full Version : I'm going to drive this thing into a wall
Alright guys,
I'm getting some greys with this car.
2002 Mustang gt, long tube headers, catted xpipe, under drive pullies, 1 piece dragon plenum/tb, bbk CAI.
After the car warms up, and I accelerate passing 3500 rpms... it coughs/looses power, then struggles.
If i accelerate very slowly, i'm okay... but if i'm merging on the highway and give it throttle... as soon as i go over 50% throttle it coughs and i lose power and the car jerks.
I've changed the spark plugs, cleaned the MAF and the TB, smoke test for intake cracks - nothing, no issues with coils, oil's good, just did a back pressure test on both cats - perfect, put fresh shell 91 octane. Still does it. I unplugged my fuel pressure sensor last night and drove it, for a minute she was doing good! Then after about 5km she started acting like she had covid.
What else can I do? Could it be the fuel pump? Anyone been through this nightmare?
hammerhead
08-18-2021, 11:59 AM
any smoke from the exhaust when this happens - maybe check compression if its a high miler or possible egr
Is the car tuned?
Fuel filter done?
Fuel PSI checked?
Is the car tuned?
Fuel filter done?
Fuel PSI checked?
Fuel filter done,
did a smoke test today and the EGR as well as the throttle shaft is pissing out smoke...more so the EGR.
Laffs
08-18-2021, 01:26 PM
Any codes? 2nd ZR's recommendation to put fuel pressure gauge on it and then drive and monitor. Sounds like its starving for fuel under load so could be fuel pump, FPDM, FRPS or even PPRV issues.
Are you saying its leaking from area around the EGR and TB as in a gasket leak, or just the fact that smoke is escaping from the ports as both open with car off?
She's runnin real lean on idle.
The actual EGR valve is flowing out smoke.
Plugged in to the fuel rail - 40psi on idle..havent taken it for a spin yet.
Ordered a new EGR, now on the look out for a new 75mm TB - hopefully it fits the Dragon plenum.
I think the car does have a tune on it, the older owner didnt know fk all about the car but said it was tuned for 91.
I'm thinking the EGR and TB will fix the issue abit .. if not - it has to be fuel pump.
Any codes? 2nd ZR's recommendation to put fuel pressure gauge on it and then drive and monitor. Sounds like its starving for fuel under load so could be fuel pump, FPDM, FRPS or even PPRV issues.
Are you saying its leaking from area around the EGR and TB as in a gasket leak, or just the fact that smoke is escaping from the ports as both open with car off?
Absolutely no codes.
Uncle Buck
08-18-2021, 02:17 PM
Seems fuel related to me
Yea, as i'm crossing the different variables off i'm thinking its either fuel related - the pump, or the tune.
Whats weird is, i can shift at 4000+ when the motor is on the colder side... but then give it 10min and boom... it starts to struggle and chokes out.
It could maybe be the tune as well, i bought a sct bdx - tuner which can unlock, i'm gonna figure out how to return it back to stock. I have a feeling it could be the tune. The guy who owned it before me knew fk all about the car and just drove it slowly on sundays.
Snaketamer
08-18-2021, 05:05 PM
Whats weird is, i can shift at 4000+ when the motor is on the colder side... but then give it 10min and boom... it starts to struggle and chokes out.
This makes me think the fuel pump is on it's way out.
This makes me think the fuel pump is on it's way out.
Alright boys, i think i'm going to take this route and replace the fuel pump.
Throwing parts at it usually doesn't get the result your looking for.
Zippy
08-18-2021, 10:56 PM
It sounds like you have a baseline tune in the car now? You'd be way farther ahead to have the car tuned by someone locally after you get the fuel situation sorted out.
Throwing parts at it usually doesn't get the result your looking for.
I agree, I'm going to check the fuel readings this weekend and see what they're like when its bogging down.
It sounds like you have a baseline tune in the car now? You'd be way farther ahead to have the car tuned by someone locally after you get the fuel situation sorted out.
Seems like it, initially I want to bring the tune back to stock so i can figure out if this issue is because of a bad tune. Most of the guys including yourselves - i've spoken too, have told me it seems to be a fuel issue. I'll do some diagnostics on the fuel side
hammerhead
08-19-2021, 11:06 AM
Seems like it, initially I want to bring the tune back to stock so i can figure out if this issue is because of a bad tune. Most of the guys including yourselves - i've spoken too, have told me it seems to be a fuel issue. I'll do some diagnostics on the fuel side
I've pulled my hair out over this many times...lol even with stock setups - the fuel can be regulated by the computer - in my experience fuel pumps work or don't work (you can try and hard wire it without the ecu) - Have an '85 Jeep here now with a Holley throttle body Nice upgrade but has its wows - when the battery voltage is low the fuel pump is shut off or and eventually stalls out if the voltage is too low won't start - there's a lot of variables to look at - had one car that would turn off the fuel pump if oil pressure is low (oil gets thin hot) (don't know if your car will do this) - the knock sensor could be detecting knock - the ecu may be bummed - I've also heard that the egr on these cars can be bypassed but I have never done it maybe something to try - poor wires can cause fits too and everyone well almost everyone never thinks of bad grounds...ask any vovlo owner hope you can work it out but don't fall into the trap of throwing parts at it and guessing
With mods you have, more likely vs not won't run correctly on stock tune.
Laffs
08-19-2021, 01:47 PM
With mods you have, more likely vs not won't run correctly on stock tune.
My car was similarly modified (full exhaust, TB/Plenum combo, JLT cold air) and ran fine on the stock tune, actually was faster on stock tune vs a canned SCT tune.
Spock
08-19-2021, 05:25 PM
O2's & long tube headers don't work well on stock tune... they run too cold
My car was similarly modified (full exhaust, TB/Plenum combo, JLT cold air) and ran fine on the stock tune, actually was faster on stock tune vs a canned SCT tune.
Not surprised, while some run fine, others shiat the bed with just CAI, absolute hit or miss.
With mods you have, more likely vs not won't run correctly on stock tune.
If I had the shorty headers on it i'm sure it would run fine, the long tubes - paired with everything else - i'll definitely need a tune.
I've pulled my hair out over this many times...lol even with stock setups - the fuel can be regulated by the computer - in my experience fuel pumps work or don't work (you can try and hard wire it without the ecu) - Have an '85 Jeep here now with a Holley throttle body Nice upgrade but has its wows - when the battery voltage is low the fuel pump is shut off or and eventually stalls out if the voltage is too low won't start - there's a lot of variables to look at - had one car that would turn off the fuel pump if oil pressure is low (oil gets thin hot) (don't know if your car will do this) - the knock sensor could be detecting knock - the ecu may be bummed - I've also heard that the egr on these cars can be bypassed but I have never done it maybe something to try - poor wires can cause fits too and everyone well almost everyone never thinks of bad grounds...ask any vovlo owner hope you can work it out but don't fall into the trap of throwing parts at it and guessing
Hope it's not poor wires because that'll be a nightmare to track. I'll be doing the fuel pressure diagnostics tonight.
*fingers crossed* hoping its a nice and simple fuel pump issue.
I'm going to leave the TB in place for now, i know theres some vaccume leaks there but i'd rather throw money on the actual issue - and i doubt a vaccume leak will cause that bogging down when its warm and at WOT.
Alright gents, fuel pressure remained steady at 40psi until i gave it the beans ...it would increase and then drop to 3.2...1.3....4.1...then as soon as id start cruising, it would go back to normal.
Fuel filter check first.
Brand new fuel filter, first thing i did when this started happening initially
Gents,
It ended up being the fuel pump. Looks like they replaced it at an earlier time with an awful quality bottom of the barrel unit.
Had the full unit replaced by a family friend and the car is running like an absolute champ, good power, strong start - figured it out!!
saleen27c
09-02-2021, 08:24 AM
Gents,
It ended up being the fuel pump. Looks like they replaced it at an earlier time with an awful quality bottom of the barrel unit.
Had the full unit replaced by a family friend and the car is running like an absolute champ, good power, strong start - figured it out!!
That’s great news! Oh man. I’ve been in this situation before too with a past ride. So frustrating when you can’t pin point the issue. It’s a great feeling when you finally resolve it and can finally just enjoy driving the car. Lol.
Nicely done................now enjoy dat bad boy.
That’s great news! Oh man. I’ve been in this situation before too with a past ride. So frustrating when you can’t pin point the issue. It’s a great feeling when you finally resolve it and can finally just enjoy driving the car. Lol.
For sure, its towards the end of the season but its okay :) Many more drives next year along with mods.
It was definitely extremely frustrating but super rewarding once everything was figured out.
Nicely done................now enjoy dat bad boy.
Haha GIV'R! Thanks guys.
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