Not doing so well, could use some help.

9

97quadcam

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Ok, now that the wife and I have successfully relocated to Houston I can get back to work on my 95. Let's start with what's been done.

97 Cobra 30k mile longblock. New parts include: spark plugs, plug wires, belt, all radiator hoses, thermostat, altenator, altenator pigtail, intake gaskets (upper and lower), IAC gasket, EGR gasket, EGR tube, Exhaust manifold gaskets, fluids and filters (gas filter will be changed soon). The gas pressure at the rail is right at 40 psi and the car always starts on the first try. Also I have new coil packs on their way, because these have 118k on them.

What it's doing: At idle it sounds like it missing. But not quite a misfire. More like a rough idle from a vaccume leak. The only time I've heard a mark run this way was when I didn't properly torque the intake on my 97. I then retorqued it and it was fine. However I properly torqued the maniflod on this car, plus the new gaskets on there...should be fine. Well I checked again and still seems fine. However in a few minutes I'm going to check the throttle body to see if it's maybe leaking...that's a new gasket too. I've used my stethescope to listen for any vaccume leaks and can find none. Also the car revs fine once past 2k rpms. And when driven the temperature creeps up on it and I'm sure it would over heat if I let it. But the temp increase isn't like that of a "bad" thermostat. It only starts getting dangerously hot when being driven. Oh and I'm not talking far...maybe a mile or so. Also no cel or any other indication of malfunction or overheating.

My questions: What's this thing doing. I'm probablly going to order a temp sensor as it was suggested that the computer may be thinking that the car is getting hot when in fact it's not and then running in safe (limp home) mode and causing the problem. Which doesn't seem to be the problem as I've driven a car in that mode and it ran rough the whole time. Also I was wondering if the Knock Sensors have the ability to cause the car to run like that. I left the Cobra knock sensors in the block and used it's wiring which is different from the mark viii setup, but looked as though the same wires from one to the other corresponded. And could the intake tube to throttle body seal be causing a problem like this. That seal is pretty dilapadated so I probablly need to buy one of them too, but I don't just want to start throwing money at this thing. Someone let me know what all the Knock Sensors control and also let me know if you've encountered something like this before.

Thank you

Justin
 
RE: Not doing so well, could use some help.

If you're worried that it might be a vacuum leak maybe you should hook up a vacuum gage to it. They aren't that expensive.

I think the knock sensors are just accelerometers that signal the EEC to retard the timing when a knock occurs. If the sensitivities of the knock sensors are different or they are different types, this signal might be wrong.
 
RE: Not doing so well, could use some help.

FWIW, I plan to R&R the intake soon and I have new knock sensors ready to go in. I wouldn't want to second guess any hard to get sensor or actuator after doing the hard part - accessing them. The same goes for the TPS, IAC, IMRC vacuum motors, etc...

The rubber seal for the intake at the throttle body is problematic.

Your description of symptoms is eeringly similar to that of a recent complaint which was apparently resolved by replacing the spark plug wires. However, since you have new spark plug wires, perhaps the coils are suspect?
 
RE: Not doing so well, could use some help.

Take the crossover fill plug out start car let it warm up a bit look for bubbles. Add fluid as needed reach over to t.b. give it some gas while watching coolant in tube watch for bubbles. Button it up when bubbles stop while its running. Your knock sensors are probably ok. You need multiple drive cycles from stone cold to full temp for the computer to learn. Next time you start it dont hit the gas nothing just let it sit there till full operating temp. Stock mark computer? stock maf?
 
RE: Not doing so well, could use some help.

Justin, now that you've successfully relocated to houston.. "we have to hook up".

Racing season is just about to kick off here in houston.

What part of town are you living in?

tommy
 
RE: Not doing so well, could use some help.

Sorry guys I didn't receive any email notifications. I'm on the west side of H-town at the hwy 6 and clay rd area. I've gone out with the tccoa guys a few times already. They're all pretty close around here. They're happy to see an active mark viii owner but I'd like to meet all you mark viii guys.

Ok this is my thoughts. The cobra knock sensors are a good bit different as is the harness...I'm swapping those out to remove all doubt. And I'll need the cobra sensors for the 97 build up...I think. The new screamin demon coil packs are on their way as is the temp sensor and the knock sensors. If that doesn't fix the problem the I'll get the vaccume gauge to make sure there are no leaks. I replaced the rear bags and pulled the intake in the past couple days in anticipation of the new parts. I'll keep you guys posted when the parts come in. Anyone want to help me throw the intake back on when the parts get here????

Tommy, I'll be out of town this weekend. I'll pm you my number just call me next week. The guys from tccoa and some of my other friends in town are going to the auto show next weekend. Some are going both this weekend and next, but we are supposed to meet up and go together next weekend since we're going to Lake Charles today.
 
RE: Not doing so well, could use some help.

Don't worry, I've burped these systems enough to know better than to leave any air in them. And the first few time I started the car I let it come to ot before trying to drive it. It still creaps up when driving. Which makes me think the timing is at fault. Only thing that makes since is the knock sensors. And yes it's stock computer, maf, pullies, and apparently the gremlins are new.
 
RE: Not doing so well, could use some help.

Sounds good.
next friday night we'll be passing right thru your area..
heading west down I-10 towards LoneStar Motorsports park for the "first race of the season".

I'll give you a call next week.. will PM you my number as well.
*ends off topic discussion*
 
RE: Not doing so well, could use some help.

>I'm on the west side of H-town at the hwy 6 and clay rd area.

I live down Hwy 6 and Beechnut.
 
RE: Not doing so well, could use some help.

I know I've seen Beechnut before. Where in relation to I10 and 290 is that?

And I'm still not getting email notifications of posts in this thread. ::wtf::
 
RE: Not doing so well, could use some help.

[div class="dcquote"][strong]Quote[/strong]
... And I'm still not getting email notifications of posts in this thread. ::wtf::
[/div]

I'll look into it, but last time I never did find a reason. ::uh::

EDIT:

The software is not showing you as 'subscribed'... perhaps recheck. Maybe even unsubscride and then subscribe again for email notifications. We have had these issues before for no explanation.
 
RE: Not doing so well, could use some help.

OK, I'll try that. It's silly. Most of the time I have no problems with it, but with this thread...I do?

Stone17-I just remembered where Beechnut is. You're a good bit south of me, but not a horrible drive. Let me know if you want to come out and have a cold one some time.
 
RE: Not doing so well, could use some help.

I was in Katy all last week. Gonna have to try to meet up with some of you texas folk when i'm down there sometime.
 
RE: Not doing so well, could use some help.

Definately do that. Let me know when you're coming and I'll buy the beverage of your choice and you can tell me how much slower my cars are than yours. But I'm not far from Katy at all.
 
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