I'll know today if they did. Wouldn't be for lack of me forwarding your suggestions. Thanks for taking the time

 

OK just sounds like someone does not understand an electronic gas pedal.
Found one on eBay for under a benjamin, Can use one for an automagic, just do not need the kick down switch (separate connector, near the middle).

 

Yeah they just threw their hands up and said they couldn't figure it out , so if you have the fleabay link, and can either post or pm, I'm all in , and appreciate it

 

Well you can either throw money at it and pray or find someone who knows what a TPS is. Takes a $5 scanner on a cell phone and a $12 dongle to both monitor and log while driving to review later. A momentary dropout would be exactly like taking your foot off the gas momentarily.
BTW there is a long section on the TPS diagnosis starting on page 9-257 of the '04 factory service manual
ps while I have a '04 Coupe with automagic now my first Crossfire was an '07 Coupe with a six speed. Been there, have the hat.

 

Hi everyone. I followed several tips from this group, replacing the foot pedal, the mass airflow sensor ( only warning that came up after being screened ) and for good measure, I changed the fuel filter. The car is still abruptly slowing down, then back to normal.
One mechanic said it could be the fuel pump, but the last reading on that showed it working ok. Could this be a ECU issue? I had two xfire techs who post on these forums look at the car, and no diagnostic reading beyond the MAS comes up. What's everyone missing?

 

TPS . MAS and fuell filter just replace, and problem continues. Would a fuel pump cause that momentary loss, despite reading a normal pressure at the shop? should that be the next replacement, since no readings come up?

 

If it is a abruptly slowing down it could be also a issue with the ignigion system or the spark plugs. But as it only showes up when you are accelerate not when you are cruising I don't think so. Maybe it's a problem with the throttle valve.
But please have a look at the air filters, not that they are full of dust.

 

If it is a wiring issue, change all the components you want and will not fix. Need instrumentation to find.

 

Not sure what to make of this. It's been run by three different computers, including two Xfire pros ( Brian Hoffman being one ) and all it showed was a MAS issue. What instrumentation and test should I do?

 

First, what you should 'do' is get all of the information. Keep reading.

I think you mean "MAF". Low fuel pressure WILL cause what you describe, but so will other items.
The fuel filter is also your pressure regulator. But the pump has to work well enough to provide 58psi at ALL times. A spotty or pitted fuel pump relay on the RCM would be a cause, as would an aging fuel pump.
There are gauges you can put on the car and watch your fuel pressure in real time, but they are expensive, I found one for $170, electric, easily installed. But didn't feel compelled to spend the money.

I find it silly that there is no fuel pressure monitoring, the ECU just assumes a pressure of 58psi and goes from there, if fuel pressure is dropping, the ECU has no clue other than looking at the O2 sensors, and thats not a really good indication of how much fuel is being delivered. But my truck and motorcycle are like this as well. A simple pressure sensor would enable the ECU to set a code if, at ANY TIME, the pressure was too low or too high. Why do all manufacturers seem to leave that out?

With not codes other than MAF/MAS, my question is this: WHAT code?
"All it showed was a MAS issue" is not complete information.

What code did you get, and was it MAF or IAT? (I ask, since the MAF assembly has both sensors in it.) This can tell us a LOT, for example, a "malfunction"code often means a connector is corroded or bad, or, if it shows all the time, you may have the wrong part in there.

 

It was the mass airflow sensor. I replaced it, and there is no code now. I'm wondering if the fuel pump is the legit source of my headache, and although it reads 58psi when tested at the shop, what you mention may indeed be the thing. I'm just tired of throwing $$ at it without a clear path to what the problem is.

 

I replaced the pump this morning, and the problem got worse. Not a cheap pump, I used the pierburg, and now it does it even more. I'm thinking the old pump was wearing out, but now that the fuel flows better through it, perhaps there is an issue with the injectors? ( the change of speed happens I try to give it gas after switching a gear ) someone said clean out the injectors using "sea foam or similar product? man, I'm fresh out of ideas, having replaced everything this thread has suggested!

 

Im hoping you changed the filter as well, because the pressure regulator is in the filter, it's a filter/regulator combination.
The idea that it got worse makes me wonder if you had any contamination in the line/tank.

 

Filter was changed.

 

I sent u8 a pm telling you to call Matt with instructions but u need to search ,,so here it first he is in miami
you are in coral springs about 50 miles or so to his shop you text him tell him who u r a nd that i sent you then he will call
you back 786 877 5959 jim

 

Matt and Brian Hoffman both came to my house and worked on the car . Hoffman said his dx showed a bad MAF, and someone here said fuel filter, so Matt, after replacing them, and the issue persisting, said it was the fuel pump. Unfortunately putting a new pump made the problem worse. I reached out to him again, cause maybe if I bring it to his shop he'll get a grip on it

 

New mechanic says it's the throttle body, not the tps. Can someone tell me the part# and or suggest where to buy? Thank you

 

There is no reason to change the fuel pump unless the fuel pressure is low, and even then, that can be the filter/regulator. Just changing parts because of someone's opinion is a waste of money, but you already know that now, don't you?

 

Needswings.com is where I would go. You need no part number with Rob, he knows what to sell you.
I am surprised Matt and Brian both struck out, that does not happen often.

Personally, I am not convinced what is going on with the car - I'd want to see it, drive it and think about it. Many times, we can diagnose a car over the internet, but sometimes, we run up against one like yours. And again, the fact that Matt and Brian struck out, really bothers me.

EDIT: The more I think about this, the more I get this picture: AT low throttle settings, life is good. At more 'open' throttle settings, things tend to go haywire. NOW< when my fuel pressure was dying, I would get EXACLTY that, see, at low throttle positions, little fuel is needed, but at higher settings, the injectors stay open longer, if the fuel system is not capable of maintaining pressure at higher flows, you will get you are are getting.

IF it was crank or cam sensor, the throttle position would not matter all that much. It appears the car has a hard time maintaining fuel/air mixture ratio at high throttle settings, again, this is still a guess. But anyway, this would be attributable to problems with fuel delivery or the MAF or throttle body not acting right.

I am reminded of a member here who had an odd trouble some years ago, some sort of issue arose in the gas tank where the fuel pickup was compromised, the fuel pump was having issues maintaining pressure when more fuel was demanded because of this. This would be obvious IF you could monitor fuel pressure while driving the car - impossible with my gauge with it's 28 inch hose. This is a RARE occurrence but something to consider.

Other than that, I keep going back to MAF/TB. If you had a code reader capable of live data (my BOSCH1100 does that), you could monitor O2 levels, throttle position, etc. while driving and you might see some parameter jump that gives a clue as to what is going on The fact that the car 'resets' if you shut it off and start it again also has my attention - I think we are all overlooking SOMETHING I just dont know what. And the fact that Matt and Brian failed shows you how rare your issue is, I still cant get over that they both struck out.

 

I've never replaced my fuel pump so I am just guessing here but is the hose from the tank to the pump rubber? If it is, could it be collapsing or kinked? Old school here.