Surging/bucking while driving

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luigisho

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Does this thng run long enough to get a fuel pressure gauge on the shrader valve on the fuel rail?

The code reader should be able to read the codes. I would erase everything by removing the negative battery cable for a few minutes and trying to start/operate the car and see what comes up. There are several things to look at. If you want to throw a tps at it I won't try and talk you out of it.

Also--looking forward (after you resolve this issue), this thing has high miles and likely needs plenty of maintenance. PITA items like timing belt and maybe rod bearings. Once the weather breaks you should consider doing it yourself.
 

Jacobvarnum

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Does this thng run long enough to get a fuel pressure gauge on the shrader valve on the fuel rail?

The code reader should be able to read the codes. I would erase everything by removing the negative battery cable for a few minutes and trying to start/operate the car and see what comes up. There are several things to look at. If you want to throw a tps at it I won't try and talk you out of it.

Also--looking forward (after you resolve this issue), this thing has high miles and likely needs plenty of maintenance. PITA items like timing belt and maybe rod bearings. Once the weather breaks you should consider doing it yourself.
It runs great with intermittent surging/bucking once it gets warm. It will typically sort itself out if I pull over and let it idle for a minute, or sometimes it’ll fix itself while I’m still driving. It will start right away first turn when it’s cold but once it’s up to operating temp it gets harder to start and the surging/bucking is more common. Sometimes it doesn’t happen at all
 

Jacobvarnum

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It runs great with intermittent surging/bucking once it gets warm. It will typically sort itself out if I pull over and let it idle for a minute, or sometimes it’ll fix itself while I’m still driving. It will start right away first turn when it’s cold but once it’s up to operating temp it gets harder to start and the surging/bucking is more common. Sometimes it doesn’t happen at all
It was not the TPS. I’ll retry the codes again tomorrow
 

SHOdded

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http://web.archive.org/web/20070510151353/http://www.shophoenixproject.com/
this site may be helpful to you

fuel pressure, iac, dpfe, dis module, and egr nostril clogging are common problems on these cars.

sometimes non-oem ignition parts can cause odd behavior, especially plugs that are not sized or heat range rated correctly. not applying enough or the proper type of thermal grease to the dis module. or simply not being grounded correctly. i had issues with the ground strap from the back of the manifold to the firewall once.

check the connector pins at the ecu, make sure they are straight not bent, clean and free of dirt/grease. is there a performance chip on the ecu by any chance?
 

luigisho

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Have you replaced the cam sensor? Is the gas that was sitting for a long time still in the system? an injector could be clogging, could be a DIS or crank sensor on it's way out. MAF sensor. Crappy ignition coil or fouled plugs. It could be the computer itself, wiring issues...

Every area of ignition and a:f mix is suspect. That is why codes can help with where to start looking.

TFI is thick film ignition module, the DIS--rectangular object mounted on the side of the intake with wiring clips on either side.
 

Jacobvarnum

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Have you replaced the cam sensor? Is the gas that was sitting for a long time still in the system? an injector could be clogging, could be a DIS or crank sensor on it's way out. MAF sensor. Crappy ignition coil or fouled plugs. It could be the computer itself, wiring issues...

Every area of ignition and a:f mix is suspect. That is why codes can help with where to start looking.

TFI is thick film ignition module, the DIS--rectangular object mounted on the side of the intake with wiring clips on either side.
I daily drive it to work everyday for the last month. It runs great for 40 minutes and bad for 5 random minutes inbetween. Can sensor is next, I have one laying around. Brand new coil 200 miles ago along with plugs. I will grab codes on my lunch break
 

Irish Pride

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It runs great with intermittent surging/bucking once it gets warm. It will typically sort itself out if I pull over and let it idle for a minute, or sometimes it’ll fix itself while I’m still driving. It will start right away first turn when it’s cold but once it’s up to operating temp it gets harder to start and the surging/bucking is more common. Sometimes it doesn’t happen at all
This description right here says cam sensor to me. Along with the no Tach issue that you mentioned in a previous post this is by the book symptoms of a bad Cam sensor. They aren't that expensive so even if you can't get the codes to pull properly I would throw one on and see what it does.

-Chad
 

Jacobvarnum

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This description right here says cam sensor to me. Along with the no Tach issue that you mentioned in a previous post this is by the book symptoms of a bad Cam sensor. They aren't that expensive so even if you can't get the codes to pull properly I would throw one on and see what it does.

-Chad
Thank you very much! I have one on the shelf at home, I’ll throw it in tonight and update this thread
 

luigisho

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Check to see if the leak at the cam sensor is alot. You may have to go in there and do some seal replacement. I say this assuming that it leaks because they always do.
 

SHOdded

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if you do need to replace seals, they are not created equal. iirc, national was a preferred brand compared to felpro. i would assume victor reinz would also do the job splendidly.
 

Jacobvarnum

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This description right here says cam sensor to me. Along with the no Tach issue that you mentioned in a previous post this is by the book symptoms of a bad Cam sensor. They aren't that expensive so even if you can't get the codes to pull properly I would throw one on and see what it does.

-Chad
Any tips on changing cam sensor? Can’t get that bottom bolt out to save my life.
 

Irish Pride

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Any tips on changing cam sensor? Can’t get that bottom bolt out to save my life.
Bottom bolt? There should just be one on the right and one on the left. I use a miniature ratchet with either a 7/32 or 5.5mm socket. I don't remember what size it is right off hand.

-Chad
 

Jacobvarnum

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if you do need to replace seals, they are not created equal. iirc, national was a preferred brand compared to felpro. i would assume victor reinz would also do the job splendidly.
I figured it out, I unbolted the power steering reservoir and got the hoses out of the way and went at it sideways. Bf I said bottom just because it’s at an angle with the left one being slightly lower. Regardless, Problem solved!
 
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