I just picked up a nice 99 cobra, all stock. I have an intermittent hesitation after 4k rpms. It still revs to redline but doesn't pull hard all time. I have tested the fuel pressure and it stays around 40psi. I cleaned the maf, changed plugs, new fuel filter, new alternator. Not sure what to check next... car has 106k and sat for about 4 years. Any help would be VERY appreciated!
99 cobra hesitates after 4k rpms
- Thread starter Justin Boisclaire
- Start date
My next thought would be coil packs. They could be getting tired. When I bought my 04 it had a miss under WOT. It slowly got worse. I ended up swapping all 8 and it's been good since.
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I dont have any missfires, doesnt feel like it anyway and no check engine light. Are coil packs a frequent issue on these cars?
At that mileage yes it is. And you don't need to spend the $350 or so to get new ones, you can rebuild the ones on the car. What happens is the rubber boot dry rots and the spring in there that connects the electronic coil to the spark plug corrodes. You can put new boots and springs on all 8 COPs for about $35. Amazon sells them and so does Rockauto. Basically doing that is like doing the "wires" on a coil pack/distributor car. The actual electronic portion of an OEM COP almost never goes bad. If the car has the yellow accel or red msd COPs on it I'd replace them with OEM tho.
If that doesn't fix it then the fuel pump would be my next thought. Or you are leaving the traction control on lol.
If that doesn't fix it then the fuel pump would be my next thought. Or you are leaving the traction control on lol.
I'd at least run a obd2 reader on it a see what it says.
I have the torque app on my Phone and a BT obd2 interface (BAFX products) that work great together.
You've shot gunned a few parts now..soo..
The car is 19YO now; so anything you replace is a good idea as a preemptive, proactive strike.
I have the torque app on my Phone and a BT obd2 interface (BAFX products) that work great together.
You've shot gunned a few parts now..soo..
The car is 19YO now; so anything you replace is a good idea as a preemptive, proactive strike.
I had some sluggishness when I got on her at 60 MPH on the highway. It turned out to be the clutch slowly going out..slippage.. I might of found it sooner, but don't get on her from 0-60 much. The longer I have her, the dearer she becomes to me..
I have a scanner so i can see what all the sensors are doing, i just wish i knew enough about it to properly diagnose the issue. So i have no codes or pending issues. My hesitation feels like this, like when the powerband is ready to kick in at 3500-4000k rpms it just doesn't just a steady increase of rpms; but other times when you reach the 3500-4000k rpms it pulls hard all the way up to redline.
Any link for the kit to rebuild the coil packs?
Any link for the kit to rebuild the coil packs?
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So i will order the coil parts today, I will also post what fixes my issue to help out others in the future!
Here's a rockauto link to the rebuild boots and coils I was talking about. Dude posted a message on my profile lol. Its all good.
More Information for STANDARD MOTOR PRODUCTS CPBK230
More Information for STANDARD MOTOR PRODUCTS CPBK230
Sorry for messaging you, did not know that was not proper. Thanks for all the help so far, i will post the results shortly
So i put in the new boots and seems to still lag a bit. Can the couls get weak without causing a check engine light? If so what kind of coils can i use to replace them?
If you replace the COP stick with stock. Aftermarket COPs have a higher failure rate and don't work as well.
You ordered the boots and got them in already??
Nah its all good but use the private message function, not posting on someone's profile.
Yes i found a set of boots locally, still same issue. Seems to happen more when it is hot. Do these cars have a variable valve timing solenoid?
No they don't. The VVT didn't start until 05.
Boots and springs too? If you just do the boots and not the springs its useless.
Yes the springs came in the kit. I am still stumped. The car has an aftermarket intake that goes into the fender and attaches to the filter, i wonder if i am getting funny readings from the maf because of it.
Where in Oregon are you ? Looking to see if I was close enough to lend a hand .
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