Injector Issue (I Think)

[ASim1579]

Lately I've been having what seems like and injector issue. For awhile my car has been having trouble starting in the morning when it's been sitting for awhile especially when it's cold which at first led me to believe it was a coolant seal failure but then I noticed that it didn't smell sweet when i would start the car and the smoke would be white but it would go away as soon as the car started. So back to the main question, are my injectors are going bad or are they just dirty and would sending them out to be cleaned solve my problem? (Sorry for the long post but I figured I would give some background on the issue lol).

[vex]

Originally Posted by ASim1579

Lately I've been having what seems like and injector issue. For awhile my car has been having trouble starting in the morning when it's been sitting for awhile especially when it's cold which at first led me to believe it was a coolant seal failure but then I noticed that it didn't smell sweet when i would start the car and the smoke would be white but it would go away as soon as the car started. So back to the main question, are my injectors are going bad or are they just dirty and would sending them out to be cleaned solve my problem? (Sorry for the long post but I figured I would give some background on the issue lol).

With that information it's hard to tell. Check a few things first: Do you have any problem with hot starts? IE: take the car up to operating temperature, turn it off and let it sit for about 10 to 15 minutes. Return and crank it. The hot start issue does play into having clogged/leaky injectors but could also further dictate low compression.

Beyond that only going off the smoke and smell isn't a very effective way to determine a crapped out coolant seal. For that you can use Kevin Landers technique to determine it, or if you're able/willing you can do my technique (A lot more involved--but you have a definitive answer). Look on www.rotaryressurrection.com for more information about that. His way involves removal of the spark plugs and checking if they're wet after a small crank without injection. If they're wet more than likely the seal has given out. If they are not, it doesn't mean the seal has not given out. The other trick of his is to heat the engine to normal operating temperatures and then let it sit for 5-10 minutes. Then crank looking for water on the plug.

For my method you'll either need a mirror and flashlight or a borescope. Remove the leading spark plug and look in the combustion chamber. If the leak is really bad you will see a pool in the rotor housing. If it's small enough, you won't get a leak on the cold engine. You'll need to pressurize the system to see if it's leaking under pressure (ie: if the engine were warm and then coolant seeped in while it was cooling, and that causes you problems when the engine is cool the next morning). If you pass those tests you're pretty safe it's not a coolant leak--though it's not 100% ruled out.

Beyond that you could look at fuel pressure to see if your injectors are clogged/leaky. You can even listen to them to see if they're functioning. Beyond that you could take them off and ship them out for cleaning. It's always a good idea

[Max777]

Well, on most fuel injection cars, you can do "leak down" testing, where you hook up a fuel pressure gauge, an injector testor, and test them, noting the starting pressure, drop down pressure, and checking these against the leak down spec in alldata. This can tell you if the injectors are leaking too much fuel.

This method works well, but for a home mechanic, you are probably not going to have the tester, and it's a bitch to get to the primary because you will need to dis assemble your intake manifold down, and remove the emissions out of the way to get to them.

I say, send them out to KG parts, Witchhunter Performance, or etc, they tend to get dirty after 20 years, so even if they dont cause a huge problem now, it's still a good idea on these cars.

PS: if you want to save some $$$ on gaskets, go to advanced auto parts, buy a roll of gasket material, and cut it. (Get the thinner yellowish stuff, dont get the thick cork stuff)

[ASim1579]

Thanks guys for the help, I was actually thinking of trying the method of seeing if there are air bubbles in the coolant while running the car with the cap off, but I will give these other methods a try. I guess I'll send the injectors out to be cleaned sometime soon since it won't hurt lol.

[NoDOHC]

One thing I found is that coolant seal failure-induced hard starting can be greatly diminished by removing the radiator cap right after the car shuts off (get a rag).

The cap can be replaced right after the car has started again.

I found this to work well on my '86 with the original engine in it (I drove it for months with bad coolant seals until I couldn't keep enough coolant in it to keep it from overheating).

If this helps that starting issue, I doubt that it is injectors.

The injectors on my '86 had 200,000 miles, 20+ years and 1 pulsation damper fire on them and did not leak at all.