'86 problem
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From: audubon pa
'86 problem
Just purchased an '86 that hadn't been driven for about 3 years. Changed oil, put in new plugs, wires, dist. cap, rotor and the thing started right up. It initially ran a little rough but after filling the tank with fresh gas and Tektron for the injectors it seemed to settle right down. Idles fine around 700rpm. Problem is that it seems to bog down and be very sluggish on take off. After the first shift the motor picks up and seems to be running ok; however, I feel like it is still "holding back". I've adjusted the TPS to .54V. The other thing is that, with the tranny in park, I seem to notice a slight miss at high rpm (2000-2500rpm). I've checked for vacuum leaks and haven't noticed any. Would anyone have any other suggestions as to what might be causing this condition?
TIA
TIA
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From: Lenoir City TN
St. Jude Donor '08-'09-'10-'11
How many miles does it have? Did you look at the ignition module in the distributor? I would also do a leak down on the injectors to make sure they are holding pressure and not flooding the engine and OHM them out as well. Is the SES light on? Make sure the sensor on the pipe that goes over the valve cover is functioning properly, that little snot caused quite a headache for me, sorry can not remember its formal name.
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From: Database Error Indiana
I would look at fuel pressure. A dirty filter will kill acceleration. Also, unhook the tan/black wire near the brake booster and check timing, Should be 6* advance with the wire unplugged. Goood luck.
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From: audubon pa
thanx for all the input. Just to try to answer a few of the questions;
1. the engine is a GM crate which the PO says has about 5k miles on it.
2. I haven't checked the ignition module. I did replace the dist. cap and just reused the old module.
3. The lights on the DIC panel aren't working (another issue I have to address) so I don't know if the SES is on.
4. I just replaced the EGR pipe with new gasket and crimp ring.
5. I did check the timing but will have to recheck it. The reason I say this is because I have initially set the TPS to .54v, drove the car a couple of days and the voltage changed to .60v. I reset the TPS and tested that, as the throttle in depressed, the voltage increases.
6. When I replaced plugs, wires, etc. I also replaced the fuel filter.
7. I'll have to check the fuel pressure.
I'm starting to wonder is I'm seeing issues with the old gas that was left in the tank. There was about 1/8 tank of gas when I purchased the car. Unfortunately, I didn't take the time to drain it. Just added fresh gas and the Tektron.
1. the engine is a GM crate which the PO says has about 5k miles on it.
2. I haven't checked the ignition module. I did replace the dist. cap and just reused the old module.
3. The lights on the DIC panel aren't working (another issue I have to address) so I don't know if the SES is on.
4. I just replaced the EGR pipe with new gasket and crimp ring.
5. I did check the timing but will have to recheck it. The reason I say this is because I have initially set the TPS to .54v, drove the car a couple of days and the voltage changed to .60v. I reset the TPS and tested that, as the throttle in depressed, the voltage increases.
6. When I replaced plugs, wires, etc. I also replaced the fuel filter.
7. I'll have to check the fuel pressure.
I'm starting to wonder is I'm seeing issues with the old gas that was left in the tank. There was about 1/8 tank of gas when I purchased the car. Unfortunately, I didn't take the time to drain it. Just added fresh gas and the Tektron.
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From: Merritt Ils Fl
Originally Posted by RRT vette
Try and check out why the DIC lights will not illuminate. The problem could be from the old gas. Do a search for "drain tank" and see what you find. It can be done by pumping or draining.
Assuming you filled the tank I would not suspect the residual fuel is your problem. If it would make you feel better add some "dry gas" to break down any moisture that may be present.
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From: audubon pa
Just to update this thread:
1. Got the DIC lights working. No codes are being generated. SES light comes on and goes off immediately after the car is started.
2. Checked the fuel pressure. Getting around 39psi which, according to the Haynes manual, is at the upper end of the range 34-39psi.
3. Set the timing to 6*. Road tested it. Advanced the timing to about 10* and it seems to have a bit more pickup. Still not what I would expect from a Vette (remember i'm new to this car).
Somehow it feels like the timing isn't advancing quick enough when the throttle is depressed quickly.
I don't know if this is a characteristic of the transmission or not but, since the engine seems to be lacking some power, the transmission seems to be shifting more than I would expect. Now I do understand that GM trannies in the late 80's early 90's had that tendency for fuel economy purposes.
1. Got the DIC lights working. No codes are being generated. SES light comes on and goes off immediately after the car is started.
2. Checked the fuel pressure. Getting around 39psi which, according to the Haynes manual, is at the upper end of the range 34-39psi.
3. Set the timing to 6*. Road tested it. Advanced the timing to about 10* and it seems to have a bit more pickup. Still not what I would expect from a Vette (remember i'm new to this car).
Somehow it feels like the timing isn't advancing quick enough when the throttle is depressed quickly.
I don't know if this is a characteristic of the transmission or not but, since the engine seems to be lacking some power, the transmission seems to be shifting more than I would expect. Now I do understand that GM trannies in the late 80's early 90's had that tendency for fuel economy purposes.
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Originally Posted by rwolak
I don't know if this is a characteristic of the transmission or not but, since the engine seems to be lacking some power, the transmission seems to be shifting more than I would expect. Now I do understand that GM trannies in the late 80's early 90's had that tendency for fuel economy purposes.
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From: WI
Originally Posted by rwolak
yes---I disconnected the EST.
Mikey Whiprek---with those kinds of comments its obvious you don't do any work on your own cars!!!!! Or if you do, I'm sure they don't run well!!!!
Mikey Whiprek---with those kinds of comments its obvious you don't do any work on your own cars!!!!! Or if you do, I'm sure they don't run well!!!!
If the trans. shift points are to close together, your trans. will fail... from a misadjusted TV cable.
Le Mans Master
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From: levittown pa. usa Even a bad day with my `Vette, is better than a good day at work
St. Jude Donor '10
Originally Posted by rwolak
Another member who has nothing worthwhile to add to the conversation!!!!
Peace
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From: Louisiana
Yes, uncalled for comments. It makes folks not want to help.
Do you hear any knocks when accelerating?
With the engine off, press the D shaped tab and push the TV cable all the way back. Then manually open the throttle plates to WOT and you should hear clicks. This is easy and adjusts the TV cable appropriately. The EST wire has to be disconnected in order to not allow the ECM to retard the timing. I would set it at 6* BTDC until you have the problems worked out. Drain all the old gas out and fill with new.
http://forums.corvetteforum.com/show....php?t=1536382
Do you hear any knocks when accelerating?
With the engine off, press the D shaped tab and push the TV cable all the way back. Then manually open the throttle plates to WOT and you should hear clicks. This is easy and adjusts the TV cable appropriately. The EST wire has to be disconnected in order to not allow the ECM to retard the timing. I would set it at 6* BTDC until you have the problems worked out. Drain all the old gas out and fill with new.
http://forums.corvetteforum.com/show....php?t=1536382
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Originally Posted by kenv
Dude!, these folks are trying to give you solid information, & you, being here only a couple of months are off to a bad start with the attitude thing.
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Originally Posted by rwolak
Another member who has nothing worthwhile to add to the conversation!!!!
Give me a reason why I should reopen this and I will/