On going problems with carbureted '89

[MAVRICK513]

I've been having problems with the carburetor for awhile now. It would run rough sometimes, idle up & down, run poorly until warmed up, etc. A month ago the thermostat stuck & the temp gauge went up just under the Hot line. I left it cool down, got it home, and changed the thermostat, etc. All seemed back to normal - ran the same & not getting hot. I finally fixed the carb & now it idles nice, seems to rev fine, etc. When I drive it though it seems very sluggish & won't rev under load. It occassionally bucks & wants to shut off too. I am getting 5 psi out of the fuel pump (as I should be), plugs, wires, etc are all good. Carb vacuum lines are all on correctly & have no apparent leaks. Ignition timing is correct. When I was playing with the carb & had the car idling for an hour or so, the fan relay kept clicking in & out & in & out (which kept turning the fan on & off). I pushed on the plugs at the firewall & the fan problem stopped. The temp gauge was fine but the coolant in the overflow bottle boiled & overflowed.

Given how the car runs poorly under load... could it now have a head or head gasket problem even though it never got really hot? How can I be sure? It has 145,000 miles on it.

[TominMO]

The temp gauge was fine but the coolant in the overflow bottle boiled & overflowed.

Given how the car runs poorly under load... could it now have a head or head gasket problem even though it never got really hot? How can I be sure? It has 145,000 miles on it.

I know what you said about the temp gauge, but I wonder if you have a clogged radiator.

[batstiva]

Okay, two things. The issue with the coolant backing up and boiling in the overflow bottle. First, I would check and make sure that the coolant is able to circulate through the rad. This is simple enough. It the rad. is not clogged, I would look at the radiator cap. Sounds too simple, I know. But auto coolant systems function under pressure. They are able to keep water liquid above the boiling point due to pressure. The cap is key to maintaining that pressure. If you have no leaks, or clogs, check the cap. I chased an overheat/leak problem around my old Dakota for far too long. Replaced the water pump (which did leak) several hoses, thermostat, and after all that, had the problem you are having. Changed the cap (which I should have done when I changed the water pump anyway) and no more problems.

As far as bogging under a load, I'd take a look at your cat. To test, get under the car, and unbolt the cat from the down pipe. Start it up, run it, and see how it acts. It'll be loud, but I'm betting it'll run a lot better. If it does, you can either gut the cat, or replace it. Before you gut or replace, if it runs better with the cat-back disconnected, reconnect the front of the cat, and disconnect the rear, just to be sure it's the cat. Also, if your locale has emissions testing, then don't gut the cat, you'll have to replace it. I believe.

[MAVRICK513]

I had already put a new radiator cap on, flushed the system with 15 minute flush, and put in a new temp switch (at the upper rad hose outlet) and a new thermostat. I didn't drive it much since then because of the carb problem. When it boiled over two nights ago the coolant was very rusty in color again. I will check into the clogged radiator suggestion. As far as the bogging goes, It didn't bog at all before the carb rebuild - it just ran lousy before it warmed up (hesitating & trying to stall). Now it seems hard to start at first but once it starts, it idles & revs nice (in the driveway). I would be amazed if it were the cat but sometimes things do go bad just at a time where it makes for a difficult diagnosis. I will try all your suggestions. Thanks!

[WmWatt]

If you think the exhaust is blocked a vaccum guage should show it. Look at the vacuum guage dianosis "sticky" at the top of the repair help forum page.

[FestYboy]

the fan was doing it's job while the car was idling, it was keepig the coolent from overheating and boiling over. whatever plug you touched at the firewall needs to go backe to the way it was. it's normal for the coolent fan to cycle at idle.

[MAVRICK513]

I removed the radiator cap at idle & saw the coolant circulating. The upper radiator hose had a reinforcement wire in it so before I could never tell if it got hard at operating temp (meaning a stuck thermostat or a blockage) so I put a soft hose on now. The hose did not get hard. Also the car did not boil over this time but the relay behind the drivers headlight was clicking on & off making the cooling fan go on & off for about 3 minutes, then it stopped. I am not sure what that means. I drained the oil & there is no coolant in it and no coolant smell at tailpipe so head gasket is probably ok. Next up is trying to run it with the cat disconnected or the vacuum test Wm Watt suggested. I will keep you posted. Thanks!

[zoe60]

I went through all that with my '89 LX. Replaced the Engine (cracked block), distributor, cat converter, wires, plugs, ignition system, triple checked vacuum lines, rebuilt the carb, and rebuilt another carb I got from the junkyard, replaced fuel pump and filter. Also replced the radiator, water pump and timing belt, just to name a few things - LOL. It still hesitated and bucked in 2nd gear ran rough when cruising and basically made me hate it! Eventually I replace the 02 sensor and viola! it ran great. I'm not saying the 02 sensor will fix all problems, but you will never get to run worth a crap with a bad one.

[batstiva]

I removed the radiator cap at idle & saw the coolant circulating. The upper radiator hose had a reinforcement wire in it so before I could never tell if it got hard at operating temp (meaning a stuck thermostat or a blockage) so I put a soft hose on now. The hose did not get hard. Also the car did not boil over this time but the relay behind the drivers headlight was clicking on & off making the cooling fan go on & off for about 3 minutes, then it stopped. I am not sure what that means. I drained the oil & there is no coolant in it and no coolant smell at tailpipe so head gasket is probably ok. Next up is trying to run it with the cat disconnected or the vacuum test Wm Watt suggested. I will keep you posted. Thanks!

"I removed the radiator cap at idle" :shock: :shock:

Assuming you did this right after start up. The fan relay kicking on and off soon after start is normal. The car is trying to regulate temp. and it will kick on and off a lot right before the thermostat opens, because the temp is getting up there. If you've got no oil in your coolant, and no coolant in your oil, I'd say your head gasket is probably okay. The vac test would be better/easier, but if you don't have a vac gauge, there's always the hard way.

[MAVRICK513]

I disconnected the cat at the front & pushed the pipe back about 2 inches. I took it for a drive & it is no better. Now I am at a loss. This thing is driving me nuts! I am open to suggestions but I don't want to put a bunch of new parts on it & get no results. Someone suggested it could be a bad coil too. Any idea how to test the coil?

[TominMO]

Another test for a clogged radiator is to warm up the car, then put your hand on the radiator at various locations. If one area is cooler than the rest, there's your sign.

BTW please put your location in your profile so we know where you are. Someone nearby might be able to come over and help out.

[clintorino]

i had a similar problem with the bucking. Took it to a shop and they said that it was running back and fourth on 4 to 3 cylinders because of the problems the ignition issue was causing... it was making the plugs and the wires bad... they said it would eventually hit down to 2 cylinders = will not run and they wanted to charge me $450 to fix... im still debating.

[MAVRICK513]

Yeah, I was just thinking ignition again. The car is very hard to start whether cold or warm. Once it starts, it idles fine but if I try to rev it with the clutch pushed in, it wants to stall at first (like there is a flat spot) and then doesn't want to rev to higher rpms. My next steps are to test the coil and change the distributor (in case ignition module is bad). Luckily I have a good spare distributor. After this I don't know what else to do. I have already sprayed carb cleaner all around the carb & vacuum lines to verify there are no vacuum leaks & all was fine.

[clintorino]

so basically replacing the dist cap, rotor, button, plugs and wires would not cure this issue? You will have to replace the whole distributor?

[MAVRICK513]

The ignition module is inside the distributor. If the module is bad, changing other components won't help. I could buy a new module (about $120 or so) & install it in the same distributor but I have another distributor that is know to have been good so I will just change out the whole thing.