88 carby timing issue

[wighty]

Hi all,
my 88 carby has an issue. After getting it running again i checked the timing with a gun and had it basically purring like a sewing machine.....(which i am told is a good thing). So I take it out for a test drive and at first its great! plenty of power and running like it used to. Then about 5 minutes in, I stop at an intersection and when I start off again, it suddenly starts losing power and even if I have it floored, it is stuttering and stumbling. I am able to limp it back home, but when i turn it off there is an odor which i am assuming is a bad air/fuel mixture and the fan remained on for a couple of minutes even when i had turned the car off and was holding the keys in my hand. It wouldnt start again, and so after going over the engine visually and not seeing anything really wrong i decided to let it cool completely off and check here on the forum before i really tore into it again. From what i have read here in the past, my first guess is to check the engine coolant temp sensor for proper function and then check all vaccum lines again( i just did a thorough check a month ago), but was hoping someone might have had a similar situation and could shed some light on what to try and what NOT to try as well....Thanks in advance

[FestYboy]

Is your cat still intact?

[WmWatt]

If it sounds like a sewing machine the valve clearances need adjusting. Did you happen to look at the temp guage on the dashbaord while it was running? If it was running hot the first thing I'd check would be the thermostat opens by feeling the two radiator hoses. Both should be warm once it opens. Sorry I have not had that unpleasant experience and can't imagine what made the engine suddenly loose power. Post any more symptoms you find and maybe someone can identify the problem.

[wighty]

I will have to check the Cat.......Does the fact that i have the required California Cat make any difference? It is only 1 year old.

[FestYboy]

Remove the cat and insert a test pipe. Most likely the cat is melted (it doesn't take much)

[wighty]

It never did run hot......which is why i found it odd that the fan kept running after i turned it off. I just assumed that the temp sending unit was going whacky. I know that it is working at least well enough to tell the ecu to turn on the fan. As for the thermostat, I recently replaced it with the jiggle pin option for 180 degree opening. But like i said, it hasnt been even running hot. the gauge moves up to the normal temp and stays there.

[wighty]

Well that simply sucks! I dont have a test pipe, but will look into that. Thanks for the help again, FestY. I really appreciate it.

[WmWatt]

A vaccum guage can be used to check for a restricted exhaust. There is a thread on how to use a vacuum guage at the top of this forum. I think a new vacuum guage is about $15. An option. Ah, of course the engine does have to be running for the vacuum guage to show a reading.

[tooldude]

If you can get by with the noise where you're at, just disconnect the cat at the front. Rig it to leave a little space, say 1/2". If that's the problem, the engine will idle/run well and accelerate. However, if not that, you saying the problem happened suddenly sounds like there could be an ignition or fuel delivery problem.

[WmWatt]

For some improvment the EGR valve which reduces engine temperature could be cleaned, an easy procedure.

I'm thinking if the timing is off and the engine is shooting flames out the exhaust ports the catalytic converter might overheat. Or maybe just an overactive imagination.