Anyone have any other thoughts?
'97 Cobra low rpm stumble/hesitation
- Thread starter Phoenix0783
- Start date
this might have been done already, but you may also check the throttle body itself. make sure its cleaned and the lil holes on each butterfly. could be that, maybe even a vaccum leak, bad seal somewhere between the maf and intake tube? pcv? have you checked the FPR?
I'll take a look at the throttle body. I've replaced the fuel pressure regulator with one I had lying around. Pressure was good with both of them at idle.
Could a bad pcv cause something like this? I may just replace it, they can't cost that much.
Could a bad pcv cause something like this? I may just replace it, they can't cost that much.
A few questions:
Are you throwing any codes?
How did you clean the IMRCs?
When you cleaned the fuel injectors, what all did you do?
You can check for vacuum leaks with smoke(you tube vids show how)or carb cleaner. The leak may not be with vacuum lines, it could be somewhere on the intake---this is where carb cleaner will help you find a leak.
Are you throwing any codes?
How did you clean the IMRCs?
When you cleaned the fuel injectors, what all did you do?
You can check for vacuum leaks with smoke(you tube vids show how)or carb cleaner. The leak may not be with vacuum lines, it could be somewhere on the intake---this is where carb cleaner will help you find a leak.
The only code that's shown up is a cylinder 1 misfire, but that was just while crusing (not bucking/hesitating). I've cleared the codes with the scanner and then I unplug the battery overnight each time I try a fix. It hasn't shown up lately, though.
I took everything apart and cleaned them by hand.
I didn't clean the fuel injectors, I bought some that had been sonically cleaned and whatnot that had new everything.
I took everything apart and cleaned them by hand.
I didn't clean the fuel injectors, I bought some that had been sonically cleaned and whatnot that had new everything.
Go to bed
O2 sensors:
It does seem to be idling better after replacing them. I'm going to drive it in the morning and see.
It does seem to be idling better after replacing them. I'm going to drive it in the morning and see.
O2 sensors:
It does seem to be idling better after replacing them. I'm going to drive it in the morning and see.
Ya, looks like it was time to replace those lol. Mine probably look similar.
Well that didn't fix it. On to the TPS and IAC!
Hope you get it soon.
TPS checked out. I also checked it with an old school dial type volt meter. No flat spots or anything.
How do I test the IAC? I took it off the intake and the plunger seems to move fine.
Also, it's idling right around 600. What should the idle be at?
How do I test the IAC? I took it off the intake and the plunger seems to move fine.
Also, it's idling right around 600. What should the idle be at?
If I unplug the IAC the rpms drop and it stalls. This means that the IAC is working?
Do you have your old injectors? Were they bad when you replaced them with the ones that had been sonically cleaned? If the old ones worked you could try swapping them back to see if the problem goes away.
The reason I ask is that I have heard of rebuilt injectors having issues--I read this in a thread while researching where someone rebuilt their injectors and installed the wrong screens which restricted things and caused problems--maybe the person/placeyou bought yours did the same thing. Just another idea to chase down.
Good luck--I hope you fix this--I hate chasing problems like these.
The reason I ask is that I have heard of rebuilt injectors having issues--I read this in a thread while researching where someone rebuilt their injectors and installed the wrong screens which restricted things and caused problems--maybe the person/placeyou bought yours did the same thing. Just another idea to chase down.
Good luck--I hope you fix this--I hate chasing problems like these.
So, after poking around I discovered that the #1 spark plug is shorting to the head through a crack in the spark plug wire boot. These are a new set of wires, so I'm going to see if rock auto will replace them. No one around here stock wires for a cobra, so I'm going to put some electrical tape (if there's room. tight fit) around the crack and see if that fixes it.
Well, the electrical tape wasn't enough to stop it. I'll just have to wait for new wires.
Here's what the plug boot on #1 looked like:
These were brand new motorcraft wires. Good thing they have a year warranty. Put another set on today. Running nice and smooth now.
These were brand new motorcraft wires. Good thing they have a year warranty. Put another set on today. Running nice and smooth now.
Users who are viewing this thread
