Jacob_Ayala

Hello to all,
I am new to forums so please bear with me. I turned to the forum when my auto mechanic failed me, and I have absolutely no experience with this issue. So to begin I will give you a history of the car while it has been in my possession. The car is bone stock with 98,xxx miles on it, about a year ago it sucked a valve, as a result, we rebuilt the entire top end. We had also recently (last 2,000 miles) done a complete tune up, this included injectors, spark plugs, air filter, and fluids.

Now for the problem. When I first start the car after it has sat for a while and cooled down to the outside temperature it runs great. It feels smooth and does not hesitate at all. Even when it warms up to optimal temperature. It is only when I start it after it has only sat for a hour or less it begins to run bad. What I mean by bad is that at idle it has a physical shake that you can feel when sitting inside of the car. The RPM's are normal as this happens. The problem continues when I drive as well, it shakes when accelerating, but happens the worst when the transmission is in a high gear going up a hill. I have read the codes and it put out two codes a 21 and 24. Have replaced the ECT, but it did not fix anything. Any help will be helpful. Thanks!

88 orangepeel notch

I'd start by looking for a vacuum leak, any small leak really messes with these cars.

It almost sounds like a couple bad fuel injectors , but that would be kinda rare as they have a good reputation. But still ohm them out to verify.

Jacob_Ayala

I have thought about those problems as well, but ruled them out because it does not happen all the time only when it is warm and I restart it. Could it still be those problems? And thanks for the response!

88 orangepeel notch

I've never had a problem with my injectors, but I've got a early 90's GM car that had this problem. Cold starts, it would purr like a kitten, but once it warmed up, it would start to miss, hesitate, run like crap. The warmer the motor got, the worse it ran. It was the injectors, they would ohm out within spec cold, but then something inside them would expand with the heat, and then ohm out way out of spec.

It doesn't sound like this is your problem as your car runs good warmed up, it's just on warm starts it does these things is what I'm understanding on your car.

And it still could be a vacuum leak for the same reason. Once a motor warms up, things expand with heat, maybe exposing a cracked hose or gasket.

Jacob_Ayala

Thank you! I will do my best to check for leaks and I will test the injectors. I will keep you posted!