89 with a miss
Thread Starter
Intermediate
Joined: Mar 2011
Posts: 41
Likes: 0
From: Bowling Green Kentucky
89 with a miss
A frustrating miss at that. Just bought this 89 Vette in Oct 2010. The car only had 34000 miles on it. Since then I've replaced light motors, rear hubs, 2 injectors, plug wires, rotor, distributor cap, plugs....dealer says the car has no error codes, YET, it continues to have a very noticeable miss as you accelerate. I'm no mechanic, but I'm tired of paying for the "well I think this will fix it" smile with his hand out service manager, if you know what I mean. Any ideas on where to look next will be greatly appreciated. 
Instructor
Joined: Apr 2007
Posts: 225
Likes: 1
From: Highland Village texas
I would start by verifying your firing order to make sure you dont have 2 ignition leads going to the wrong cylinder. Next I would check the injectors again Hot as you have 1st gen multecs that fail fast with the alcohol in the fuel nowadays. My multecs started failing at 27000 miles 4 years ago.
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 412
From: WV
I agree with checking the injectors..If you still have the stock Multecs in the car they should be replaced. There are very few owners that haven't had trouble with these injectors.. They aren't ethanol compliant so the ethanol is eating them up inside and this causes them to fail.... Get new injectors...WW
Last edited by WW7; Apr 19, 2011 at 09:49 AM.
Race Director
Joined: Apr 2003
Posts: 17,699
Likes: 1,667
From: moraga ca
a leakdown and/or compression test might be in order to make sure you don't have a bad cylinder or two (burnt valve, holed piston). Might also want to check or swap out your ignition module in the distributor. Motors run weird when those go out.
Melting Slicks
Joined: Nov 2008
Posts: 2,765
Likes: 5
Get a hold of Jon Banner @ FIC/ Fuel Injector Connection in Georgia.
Those GM Multec Injectors are terrible to use with E10 gasoline.
I bet I have changed out over 1,000 GM Multecs since the mid - late 1990's to present thanks to Ethanol in today's gasoline.
BOSCH 3's or similar would be a nice upgrade for your Vette.
Those GM Multec Injectors are terrible to use with E10 gasoline.
I bet I have changed out over 1,000 GM Multecs since the mid - late 1990's to present thanks to Ethanol in today's gasoline.
BOSCH 3's or similar would be a nice upgrade for your Vette.
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Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Well, since a lot of head gaskets were leaking under warranty, I'd just take a peak at cylinder #7 - since that's where the majority went bad. From there, you can track the miss to a single cylinder with some 1/4 inch vacuum hose. Cut it into 1 inch lengths and then place a piece between the plug wire and Distributor tower. Touch the vacuum hose with a grounded test light while observing a Tach and that will kill the cylinder. Note the drop. No drop or a smaller drop than all the rest is the bad cylinder. If it's #7, the head gasket is probably leaking.