Lumpy start

Paulbav · 06-25-2004, 10:48 AM

Hi all

Hope someone out there can help me?, the last 2 times I have started my 89 3.2 up it has felt like there is something wrong the whole car vibrates as if the engine is loose!yet it definatly isn't! it also feels very under powered., this seems to continue untill it is warm and I put my foot down then it feels like a turbo lag as the engine sudenly comes to life and returns to normal and idles and runs perfectly.
Any help would be very appriciated my thought was its not firing on one or more cylinders??? but why would it then suddenly start to?.

Ps I came back from Le Mans last week after doing 1000 trouble free miles and this has occoured both times I've started it since! Doh!

Paul

scottb · 11:17 AM

Did you possibly get a bad tank of petrol? Try running some Techron thru the system and see if it smoothes out.

Paulbav · 06-25-2004, 11:03 AM

Actually we did get some crap petrol in france one of the cars really stuggled on it! I'll give that a go what is techtron? can I get it in the uk ?

Paul

scottb · 11:18 AM

On this side of the pond, Techron is a product made by Chevron. It cleans out the fuel system, and does a great job on P-cars. I don't know if it's sold in the UK, but I'm sure there is something else there if it isn't.

If you've got a bad load of petrol, you probably have only two options. The first is to drain/siphon what you've got in the tank, and get a fresh tank of fuel. The second is to keep driving it and periodically add fresh fuel as the tank empties (every five gallons or so). If the tank is relatively low now, take it to a filling station you trust, fill it up with the highest octane fuel the car will tolerate and see if that helps.

Good luck, and let us know what happens.

kach22i · kach22i's Garage

I was going to say "points", but your car doesn't have any, right?

Watch using any fuel cleaners, they might make your oil leaks worse. Let's just say, it did not help mine.

I have read that you must change your oil within 500 miles of using the product. It leave residue/deposites than may thin out or ruin the oil.

geof33 · 06-25-2004, 12:52 PM

Quote:

Originally posted by kach22i
I was going to say "points", but your car doesn't have any, right?

Watch using any fuel cleaners, they might make your oil leaks worse. Let's just say, it did not help mine.

I have read that you must change your oil within 500 miles of using the product. It leave residue/deposites than may thin out or ruin the oil.

Not to hijack... Say what??? I've never heard of that before. DO we have another endless debate thread in the works???

scottb · 06-25-2004, 12:56 PM

I've heard the same thing...that you should change your oil after running Techron for 500 miles or so. Do a search here on the board, I think this issue has been debated and beaten to death many times.

john70t · 06-25-2004, 02:23 PM

I've heard from several teachers/mechanics that the Techron is the only fuel cleaner to use for fuel, GM(?) top end cleaner for gummy cylinders, and Rislone for sticking lifters. Changing oil soon after is a good idea after anything.

The fact the top end is strong indicates good fuel flow, but there may be a piece of crap in the tank that's being sucked up at idle (not likely).

I'd guess a bad head temp sensor or airflow sensor that's making if run super rich all the time. Second guess is a stuck distributor advance.