Dolfan

OK, 1989 coupe, stock, 77K miles

Car has run typically very well for years, ran AS SCCA until purchase of a Z06 3 yrs ago. now car is just a around town cruiser. The engine is stumbling, idles poorly and overall rough lately. No service light on, but not sure if any codes thrown. Plugs, wires and distributor parts have maybe 3-4K on them.

What steps should I take in getting this running better? Here are the things I have as a list of things I think I should do.

-Compression test, check overall status of the cylinders/valves/etc.
-Check plugs for color/oil while doing comp test.
-Set Timing, never done this on the car.
-Read trouble codes for any data
-Check/replace fuel injectors
-Get ALDL cable and scan software to monitor engine parameters.

This is my plan of attack but I'm sure there are those more knowledgeable on this engine that will suggest other things. Please offer any and all ideas from you experience.

Chris_M

I'd look at the injectors first, they're a known issue with the 89 cars, and can cause the problems you are describing.

pkazsr

I don't have any problems yet, but FICInjectors will be getting a call soon.

engle1147

The injectors on my '89 just up and died in '07 ....they ohmed OK but they were the culprit. Jon's the man!

neversatisfied12

Sounds like injectors to me also...I would take that as my first test-If I were you.

Dolfan

I to suspected the injectors, but if I ohm them and that shows OK, it skill could be the internals on them other than the coils. Don't know how to check that I'll have to look into that.

navy_vette

I have had something like this before. I agree that it is probably the injectors. I'm starting to have that two. However, i have also had a major problem with the distributor. For some reason, the distributor holder in this motor is a pain. I have had to tighten the bolt for it 3 times. Since you say that it is a fairly new distributor with only 3-4k on it, i would check that it is tight. If it is not, then every time you start the car the distributor will jump a bit and your timing will retard just a little.

This isn't really that likely, but something you might want to check into.

gmboileau

Isolating the problem will save a lot of work and expense.

From your list of activities this is a good way to start.
"Get ALDL cable and scan software to monitor engine parameters."

If your ECM is getting bad data from sensors it can make the engine run poorly.
For example if your Temp sensor is out of range this could cause the car to run rough but not set a code. This would show up in the data stream.

Dolfan

Slight miscommunication on this, only the plug wires and distributor components are new, not the actual distributor. It hasn't moved. That being said one of the items is to establish the base timing to get everything set.

Dolfan

This is new territory for me with the computer in the garage, but I do realize that this should give me much better insight into what is really happening.

aklim

If you suspect injectors, take them out and have them tested. Before that I would check compression and spark quality.

cmcbunch

Now that I have winaldl I dont know how I tolerated working without it. On a fuel injected car you cant do anything without a scan tool. You'll just be shooting in the dark. You gotta see what the ecm sees. The first thing I do is look at sensors before anything else. Let us know how it turns out.