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Discussion Starter · #1 ·
At first start up, it runs fine. After driving for awhile I turn it off. After starting it up about an hour later, it starts shaking and running very rough until I rev it up and keep giving it gas. Then it will clear up and run fine until it's shut off and the cycle is repeated. Not sure what it could be. However, it first started doing this at the car wash. I just got it back together after pulling the passenger cylinder head to fix a broken exhaust manifold bolt. Not sure if any of this is related, but I'd thought I'd just throw that out there. Whatever it is, it's not consistent. I've checked the vacuum lines and I see nothing amiss. Also, not sure if it's related (probably not), the primary cooling fan won't come on unless the AC is on or unless I unplug the temp sensor. Replaced and tested the new sensor too. It tested good. Help!!
 

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Basics first ~ check fuel pressure ~ should be 40+ PSI

Check to see if the opti got wet ~ if so it may dry out. Is the opti vent harness working?
 

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Your fan sounds like it's working the way it should....they don't run all the time you know.
 

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Discussion Starter · #5 ·
Yes, but the temp gauge will eventually max out and it will never come on.
 

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Discussion Starter · #7 ·
Ok, so I did a few checks today. It hasn't rained in a while, but I decided to check the opti for water build up. I blew compressed air through it, but it was bone dry. I don't think a wet opti is the problem. At this time, I have no access to a fuel pressure gauge, but I did check vacuum and it was 25 and about 19 when in Drive and the brake held.

As far as the temp sensor goes, that one has me scratching my head. The primary fan comes on when the gauge is right about when it hits the red. Not cool. I've checked the resistance values and they seem to be correct.
 

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Ok, so I did a few checks today. It hasn't rained in a while, but I decided to check the opti for water build up. I blew compressed air through it, but it was bone dry. I don't think a wet opti is the problem. At this time, I have no access to a fuel pressure gauge, but I did check vacuum and it was 25 and about 19 when in Drive and the brake held.

As far as the temp sensor goes, that one has me scratching my head. The primary fan comes on when the gauge is right about when it hits the red. Not cool. I've checked the resistance values and they seem to be correct.
$15 at Harbor Freight near you for a decent fuel pressure gauge. You fan operation is normal and OK. There is a wealth of info on this site for your situation.
 

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check aux batt post to be sure its brass version, then on to opti which is probably the problem.
 

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$15 at Harbor Freight near you for a decent fuel pressure gauge.] ha ha i bought one of these gauges and when i went to check my pressure the gauge filled up with gas,it was classic chinee sh*t,the hose did work good with a better gauge though,just my experience ,not worth taking back since i had a good gauge to use
 

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screwed that quote up didn't i
 

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My '96 SS has been hard to re-start and runs rough for a few seconds too. I gotta kinda clear it out. I've been attributing it to leaky fuel injectors, but they didn't seem to leak when I raised the rails and took a peak. It all seemed fine, but I figure I'll try pulling them and soaking overnight in Seafoam. Mine's accompanied by a racing idle at times as well.

I'm not sure how any of that helps you, but if you get yours fixed it might help with mine too.

-KP
 
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