Newby looking for help,

 

I just bought a 82 coupe with only 73000 miles on it all original.  Got the intake manifold gaskets replaced as it had a vacuum leak (as I was told by the seller).  Car runs well except that it hesitates/chokes up when it is coasting and you give it a little gas (very slight touch on the gas).  When it is cold, and I try to give it a little gas as explained above, it will actually blow out the line on the slave TBI unit that goes to the EGR solenoid.  If you give it gas faster, it will not choke up but it also does not burn any rubber lol. 

 

Any ideas??  The car sat for a while so it needs to stretch its legs (which I am very happy to do) but throttle response should be better than I am getting.  Thanks in advance.

Welcome aboard!
Also check out the CFIV forum, it is all about our Crossfires!
http://www.crossfire.homeip.net/index.php?act=idx
What do you mean by "blowing out the line"??
You may still have a vacuum leak - check your throttle shafts on the tb's, if they have play up/down, left/right to where you can even hear it chattering, you may need to get the shafts bushed. This is a normal place for a bad vacuum leak on a CFI and they don't handle even small leaks well.

  Also, sounds like maybe your fuel pressure is too low; GM calls for 11 psi but in reality it needs 13-15 psi -  a stock fuel pump, even a new one is insufficient and you will be lucky to get even 11 psi from one.  One of the normal modification CFI'er do is to replace the oem pump with a 85-87 pump where you can get like 35 psi though you'll need only 14-15 psi. Sluggish and hesitantion is symptoms of low fuel pressure.

  You are not going to get much rubber from a stock 82..... a few mod's later and maybe a gear change....

  I'm sure others here will give you more info as we have some good knowledgeable gearheads and some CFI.....................ers here.

Phill's Vette2009-09-04 16:25:51

Im curious as well about exactly what you mean about blowing out the line to the egr solinoid, never heard of that one.  As for the hesitation, I agree with Phill about the fuel delivery but there are a few other things you can check in that regard.  Id change the fuel filter which is located on the passengers side frame rail pretty much where the passengers feet would be. Replacing the fuel pump isnt a bad idea but even if you arent going to replace the fuel pump I suggest you pull the pump and check the flexible rubber hose that connects the pump discharge to the line leading out to the engine.  If your pump is original these hoses are notorious for deteriorating and restricting flow to the engine.  The link above is of a buddy's 82 fuel pump that we changed about 6 months ago. He was also having hesitation problems.  We ended up replacing his fuel pump as well as a couple other tweaks.   If you decide to pull the fuel pump and arent quite sure how, give us a hollar, it can be done but is a little aggrivating.  We can give you some tips that will make the job simpler with less  blue language.

The hose literally comes off the metal pipe it is attached to at the tbi.  We replaced it with a new hose a few days ago.  I have to check but I don't think it has happened since.  Before I picked up the car from the seller, his mechanic replaced the fuel pump and filters.  I will ask him what kind of pressure the pump is rated for.  I think he did tell me that it was more than stock. 

 

I can only assume (yeah I know) that he changed the hoses also.  I will ask him.  Thanks for the info.

Thanks for the info.  I will check the shafts tomorrow and will let you know. 

I did not tell you before, but the seller's mechanic had removed the cruise control system previously (don't know why just not fix it) and I have hose looped into each other at that location.  I am getting diagrams to see where these hoses should be and doing a better job of "removing the system.  He left all of the hoses and either capped them or looped them.

 

Don't think he will be working on my car anytime soon lol.

If he changed the pump, he would have surely replaced the short "in tank" hose as well, it comes with the pump so that is one area you can probably forget about.  Although increased pressure from a new pump 85 corvette pump can be beneficial, a new 82 pump that is to factory specs will provide all the pressure your throttle bodies are set to use unless they have been modified to provide more pressure.  The pressure regulator is in the drivers side throttle body but is "sealed" from the factory. If the same problem exists as before, I doubt its the pump or the "in tank" hose. What you are describing has been called the "crossfire stumble" and it can result for a number of reasons but part of the problem could be that the two throttle bodies are out of balance.  The drivers side throttle body feeds the passenger side cylinders and the passenger side throttle body feeds the driver side cylinders.  In order for the engine to run smoothly both throttle bodies must be exactly syncronized.  If BUBBA has been messing with the linkage then this could also be part of your problem.  You will find instructions for balancing the throttle bodies at the link that Phill posted earlier, its not difficult, just takes a little time and the home made manometer they show in their technical section works like a champ and costs less than $10.00 to build.  Keep us posted as we all learn from feedback about what works and what dont.Crossfire19822009-09-07 13:41:00

I was going to suggest the fuel pump as that fixed my hesitation problem.