[gunther]

Engine pulsing, dies at idle… HELP!!

The car is an ’88 bird with the 5.0 V8. It ran fine Saturday, got in it Sunday to go to the store and it ran like crap.

At idle the RPMs drop till it just about stalls then they it revs back up again then drops, it does this a few times then it dies. If I give it a little gas, it will pulse faster and not die, the more gas I give the faster and smoother the pulsing becomes.

When I put it in drive it is OK, as long as I am accelerating. If I try to coast or accelerate lightly the engine pulses and the car bucks (Between 30 and 55 MPH it bucks violently.) If I just coast its fine, but it seems to feels as if there is a more drag from the engine than normal.

Any ideas what is up? What should I check? I have to drive this car for the next 2 weeks in traffic before I can afford to have my mechanic look at it, so any help that will let me fix this myself, if only for the short term, is much needed.

Thanks a ton in advance!

Gunther.

 

[Alex]

Sounds like what happened to my engine. If it is in fact what happened to me, you have a leaking piston, meaning there's something leaking inside it; whether it be water or oil. If they can find the leak, they can try to patch it; BUT that rarely works. In other words, your engine is gone. That's right,i'm on my second engine. Anyways, if this symtom just started, you got like a good 5 miles of driving before it gets really bad. ALSO, check plugs on your distributor to see if any got loose.

 

[Gonzalo Duque]

This may sound off the wall, BUT

See what happens if you loosen the gas cap, and drive with it off. My 88 Thunderbird with the V8 did the same thing and it was determined that the fuel lines at the tank needed to be replaced. My Thunderbird surged like crazy and would smooth out when the gas pedal was pressed. I had a mechanic friend replace the fuel lines coming out of the tank for me, and at his suggestion I replaced the gas tank since it was getting rusty. This was around 1997, and a tank cost me around $125 or so. It never had that problem again. Also replace your fuel filter! It's located on the passenger side just behind the door.

 

[gunther]

Ok, I did a little work on the car. I changed the plugs and wires and verified that there was spark on each cylinder.

Changed the fuel filter, the one that was there was good, but I changed it anyway.


The plugs I removed were black. The car is also giving off black smoke in the tailpipe (this just started). Fuel economy is really bad, it seems that I am using two times the amount of gas to go the same distance at the same speed.

And its still bucking at a steady rate when coasting or idleing. And it dies if I dont give it gas at idle.


I checked the Vaccum lines, and I didn't see any leaks, but I am no expert and might have missed some.


So.... Any ideas?

 

[Thyg0d]

Could be your MAF that's gone south...

One of my collegues had that on her ford...
As soon as she pushed down the clutch it would react
just like that and if she pushed the brake it died due to the change in vaccum...

Take the sensor out and clean it...

Could help, and a lot cheaper than changing engine...


Reg's
//Per A

 

[Gonzalo Duque]

No MAF on a 1988 5.0L

I'm pretty sure there is NO MAF in the 1988 Thunderbird. There is a MAP sensor, which stands for "manifold absolute pressure" which he could change, and that should be on the firewall.

Gunther, have you tried the gas cap suggestion I gave? If not, please do and see what happens. If there's no change then it's something else. Have you changed your oxygen sensors? Try taking it to Auto Zone, since they give free computer code readouts and see if the computer is showing any codes. Sounds like you may have a sensor that has gone bad somewhere.

 

[gunther]

Yeah I tried to take the cap off as soon as I read you post but no good.

The spark plugs were black when I took them out and black smoke came out the tail pipes (Through my new dual exhaust suystem...) that means its running rich, right? So I would think that would mean there is probably no blockage in the fuel lines... Am I wrong?

You might be right about the O2 sensors, when I had the exhaust done I decided against having them changed (had a bad feeling bout not changing them, but didnt have the money). Ill kick my self in the *** it thats the problem.

I have an autozone right down the road, I will take it there for a scan. That sounds like a good idea.


I bit the bullet and put my other car on the road (an 89 SC). Really wanted to leave it off the road and sell it but the 88 is not drivable. But I cant complain, driving the SC is a BLAST Ill sell it once the ol' 88 is going again.


Oh, yeah... no MAF in the 88, its speed density.

 

[94T-Bird]

similiar prob

My 94 bird did similiar things.
Don't know what kinda set up is in the 88 you have but mine was the emmission computer. Had to be replaced.
Just some input.