1988 LTD Crown Victoria LX Bucking Hesitating Mid Throttle Help!

[1988CrownVicLX]

I have a 1988 LTD Crown Victoria LX 5.0 liter EFI with 107,000 miles on it in excellent body and interior condition and have been told it looks brand new by a lot of people. However I have done a considerable amount of work on and I still can not fix the main problem I set out to fix.
Let me start out that this car belonged to my uncle and sat in his garage for a number of years, then I brought it to my house where it sat outside on concrete for approximately 2 years. Back in April I tried to start it and it only cranked. So I found the fuel pump to be bad and replaced it. Then I decided to change the oil and put new plugs in. When I started it after this I noticed that the engine ran really rough and the whole car shook, and drove really really bad. The car shook at idle (like sitting in a massage chair), upon acceleration it also shook much worse, practically undriveable. Figured well I dunno what to do with it so I let it sit for about a month till I got back to it. Did some reading up and came to the conclusion that one of the injectors maybe blocked up from it sitting so long. Got all new injectors and put those in, upon restarting the car with the injectors in it. The wonderful TFI-IV ignition module failed. After buying the nice special tool for taking it off and the new module the car started and seemed to run a tiny bit better.
Ater being quite upset that all that work did not solve my problem.
I Took it into a diagnostic place and (they had it for 3 days) told me that there were no coded stored in the computer and there was no check engine light on, and the valves needed to be reworked on cylinder 1 and 6 and my BOSCH platinum plugs were not motorcraft and needed to be changed and would cost between $1500-$1800. After I told them no and paid my $76 I decided to do the work myself. Took the cylinder heads off and put remanufactured ones on the car as well as new cats, it seemed to run a lot better however it still shook, only at mid throttle the worst being from 25-35 mph (right when the transmission shifts and the rpms drop). Took it into the transmission shop and the guy siad that the grommet on the throttle body wears out and this may fix the problem. Upon inspection, sure enough the grommet was cracked and the kickdown for the trans was unhooked. Upon installing a new grommet and hooking the cable back up the car ran even better but the 25-35 mph bucking was not solved the trans turned out to be fine.1
Thorugh all of this I noticed that the air would shut off and the heat would come on while accelerating. When this would happen the signiture green mist of anti-freeze would coat the window due to a bad heater core. Thought to myself great another thing to change. After ripping apart the whole dash to discover the upper left hand screw behind the plenum duct work i had the heater box out and the core changed. After this I changed the belts and the plug wires.
Still the car ran a little smoother but the air still shut off and after reading some threads on this post I discovered the coffee can vacuum resivior had a hole in it the size of the inlet. When I changed this the cars air works fine, but it still bucks and lacks power.
Having reached the point of no return and being at a complete loss I decided to take the car into the $tealer. Hoping that they would find the problem they came back with this: the ingnition coil failed their test, the iac needs to be cleaned (even though the book tells you not to clean them due to a coating on the valve), the stator needs to be changed, the "aftermarket" ignition module is not motorcraft and needs to be changed as well, repair as many vacuum lines as possible and finally the plugs should be changed to motorcraft ones. They wanted to do this for the bargain price of $1200, upon which due to the vechicles age there may be other considerations once repair due starts. After paying $80 for this wonderful diagnostic and buying my own "aftermarket" stator which had no effect on the car. I am at a complete loss. I tested the throttle position switch, the iac sensor, the oxygen sensors and the egr sensor, all check out to be fine. Wondering if it is a vacuum problem, fuel probelm or what? Everything I have done has helped the cars running.

[amo4387622]

When you test the Tps what do you get for a voltage on it? Because my car use to do the samething between those speeds. But i went out and bought the Casper throttle enhancer and it fixed my problem for me. But just because the dealers say to run motorcraft parts you do not have to run motorcraft parts for the car just as long as you get good quailty parts to replace the stock parts.

[cobradude360]

amos right bout the motor craft but u have to run autolite or motercraft plugs for best erformance

[puddy'sbrother]

I'm having nearly identical problems with my '88 Crown Vic LX 5.0. The car hesitates at 30-35 mph right at the shift point as if there is not enough power after the drop in RPMs. When the weather is hot (95-100) it absolutely bogs down in the shift. Been to the dealer -engine is fine, no vacuum leaks, compression is good. A reputable transmission shop adjusted the trans and says it's fine. The Radiator is fine. Replaced: fan clutch, EGR valve, TPS, air bypass valve, cap, rotor, plugs, etc...
I would love to hear anything you find out and would gladly share anything I learn.

Anyone else w/ any info would be helping two of us.

[gurinski]

Originally Posted by 1988CrownVicLX

I have a 1988 LTD Crown Victoria LX 5.0 liter EFI with 107,000 miles on it in excellent body and interior condition and have been told it looks brand new by a lot of people. However I have done a considerable amount of work on and I still can not fix the main problem I set out to fix.
Let me start out that this car belonged to my uncle and sat in his garage for a number of years, then I brought it to my house where it sat outside on concrete for approximately 2 years. Back in April I tried to start it and it only cranked. So I found the fuel pump to be bad and replaced it. Then I decided to change the oil and put new plugs in. When I started it after this I noticed that the engine ran really rough and the whole car shook, and drove really really bad. The car shook at idle (like sitting in a massage chair), upon acceleration it also shook much worse, practically undriveable. Figured well I dunno what to do with it so I let it sit for about a month till I got back to it. Did some reading up and came to the conclusion that one of the injectors maybe blocked up from it sitting so long. Got all new injectors and put those in, upon restarting the car with the injectors in it. The wonderful TFI-IV ignition module failed. After buying the nice special tool for taking it off and the new module the car started and seemed to run a tiny bit better.
Ater being quite upset that all that work did not solve my problem.
I Took it into a diagnostic place and (they had it for 3 days) told me that there were no coded stored in the computer and there was no check engine light on, and the valves needed to be reworked on cylinder 1 and 6 and my BOSCH platinum plugs were not motorcraft and needed to be changed and would cost between $1500-$1800. After I told them no and paid my $76 I decided to do the work myself. Took the cylinder heads off and put remanufactured ones on the car as well as new cats, it seemed to run a lot better however it still shook, only at mid throttle the worst being from 25-35 mph (right when the transmission shifts and the rpms drop). Took it into the transmission shop and the guy siad that the grommet on the throttle body wears out and this may fix the problem. Upon inspection, sure enough the grommet was cracked and the kickdown for the trans was unhooked. Upon installing a new grommet and hooking the cable back up the car ran even better but the 25-35 mph bucking was not solved the trans turned out to be fine.1
Thorugh all of this I noticed that the air would shut off and the heat would come on while accelerating. When this would happen the signiture green mist of anti-freeze would coat the window due to a bad heater core. Thought to myself great another thing to change. After ripping apart the whole dash to discover the upper left hand screw behind the plenum duct work i had the heater box out and the core changed. After this I changed the belts and the plug wires.
Still the car ran a little smoother but the air still shut off and after reading some threads on this post I discovered the coffee can vacuum resivior had a hole in it the size of the inlet. When I changed this the cars air works fine, but it still bucks and lacks power.
Having reached the point of no return and being at a complete loss I decided to take the car into the $tealer. Hoping that they would find the problem they came back with this: the ingnition coil failed their test, the iac needs to be cleaned (even though the book tells you not to clean them due to a coating on the valve), the stator needs to be changed, the "aftermarket" ignition module is not motorcraft and needs to be changed as well, repair as many vacuum lines as possible and finally the plugs should be changed to motorcraft ones. They wanted to do this for the bargain price of $1200, upon which due to the vechicles age there may be other considerations once repair due starts. After paying $80 for this wonderful diagnostic and buying my own "aftermarket" stator which had no effect on the car. I am at a complete loss. I tested the throttle position switch, the iac sensor, the oxygen sensors and the egr sensor, all check out to be fine. Wondering if it is a vacuum problem, fuel probelm or what? Everything I have done has helped the cars running.

Maybe check the motor mounts