Morning Startup
Thread Starter
Pro
Joined: Aug 2002
Posts: 715
Likes: 0
From: Warner Robins GA
Morning Startup
Hey again guys,
Still trying to get kinks worked out of this car I recently bought.
It's an 88, and it seems to be running very well at 104k miles. In the mornings though, when I first start it up the idle is about 500 rpm and a little rough. I wouldn't say there's any danger of it dying, but it's definitely not as smooth as when it warms up for a minute.
The guy I bought the car from assured me this was normal in a TPI system (which I believe it may be fairly COMMON, but not normal).
If I give it a little gas (up to maybe 1200 rpm), the roughness will almost definitely go away for the most part.. but it only drops to about 1000 rpm. It's smooth as usual at this point, but the RPM's are too high I think. Also there's a somewhat gassy smell in the exhaust.
If I don't give it any gas, it'll smooth itself out over a few minutes. Still a gassy smell in the exhaust. It doesn't just start rough and instantly become smooth though. It's gradual. It's only in the mornings (when it's cold and lots of condensation I suppose) when the car first starts.
I'm wondering if maybe there's a blown head gasket causing a very slight water leak into the cylinders. I'm not a mechanic, but I think I could take care of this if it's the problem.
Any opinions?
Thanks much.
Still trying to get kinks worked out of this car I recently bought.
It's an 88, and it seems to be running very well at 104k miles. In the mornings though, when I first start it up the idle is about 500 rpm and a little rough. I wouldn't say there's any danger of it dying, but it's definitely not as smooth as when it warms up for a minute.
The guy I bought the car from assured me this was normal in a TPI system (which I believe it may be fairly COMMON, but not normal).
If I give it a little gas (up to maybe 1200 rpm), the roughness will almost definitely go away for the most part.. but it only drops to about 1000 rpm. It's smooth as usual at this point, but the RPM's are too high I think. Also there's a somewhat gassy smell in the exhaust.
If I don't give it any gas, it'll smooth itself out over a few minutes. Still a gassy smell in the exhaust. It doesn't just start rough and instantly become smooth though. It's gradual. It's only in the mornings (when it's cold and lots of condensation I suppose) when the car first starts.
I'm wondering if maybe there's a blown head gasket causing a very slight water leak into the cylinders. I'm not a mechanic, but I think I could take care of this if it's the problem.
Any opinions?
Thanks much.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Morning Startup (Tourney3p0)
Well, it's NOT common for a TPI, but doesn't sound like a big deal either.
There are two things that come to mind: 1) the IAC and 2) the cold-start fuel injector. Since the cold idle is low and it has a "gassy" odor I suspect the IAC is not opening to allow enough air.
Use some intake cleaner on the TB and throttle plates; pull the IAC valve from under the TB and clean it and it's bore.
There are two things that come to mind: 1) the IAC and 2) the cold-start fuel injector. Since the cold idle is low and it has a "gassy" odor I suspect the IAC is not opening to allow enough air.
Use some intake cleaner on the TB and throttle plates; pull the IAC valve from under the TB and clean it and it's bore.
Thread Starter
Pro
Joined: Aug 2002
Posts: 715
Likes: 0
From: Warner Robins GA
Re: Morning Startup (65Z01)
Thanks for the response!
When I bought the vehicle he gave me a list of things that have been done to it, and back in March the cold start sensor was replaced and the injectors were marked as "repaired". I guess he was trying to fix the same problem. I'll take a closer look at the cold start injector.
In any case, thanks for the help! I'll see what I can do with the IAC.
[Modified by Tourney3p0, 3:59 PM 9/18/2002]
When I bought the vehicle he gave me a list of things that have been done to it, and back in March the cold start sensor was replaced and the injectors were marked as "repaired". I guess he was trying to fix the same problem. I'll take a closer look at the cold start injector.
In any case, thanks for the help! I'll see what I can do with the IAC.
[Modified by Tourney3p0, 3:59 PM 9/18/2002]
Le Mans Master
Joined: Jul 2002
Posts: 5,818
Likes: 2
From: Alive and well in Burlington NC
Re: Morning Startup (Tourney3p0)
Lets start simple. You may only have a dirty throttle body. Get some good cleaner for throttle bodies (not carb cleaner) . Clean the opening with the throttle in the idle position (engine off) then open the throttle to WOT and clean the backside of the plates. Use a clean rag to remove any gum build up that you can see. Wait a few minutes and reassemble and restart. Next step would be to remove the throttle body for a good cleaning.
Burning Brakes
Joined: Feb 2000
Posts: 824
Likes: 2
From: Camden SC
Re: Morning Startup (Steel Blue 91)
Another thing you may consider further down the list is the Coolant Temp Sensor (CTS). If you have access to scanner, hook it up when cold, and check to see if the CTS is close to ambient temps. Cleaning the throttle body and passages is always a good idea for any idle problems. Good luck.
dlmeyers 90 coupe zf6 3 speed shocks
dlmeyers 90 coupe zf6 3 speed shocks
Team Owner
Joined: Mar 2000
Posts: 83,383
Likes: 87
From: Boston, MA
The TPI engines are supposed to go into a high-idle mode until the oxygen sensor is warm enough to start giving readings. Mine will typically idle around 1100 RPM until the sensor kicks in and then drops down to my set idle of 875.
Drifting
Joined: Feb 2000
Posts: 1,994
Likes: 0
From: Charleston, WV
Re: (scorp508)
That car's running a little rich at startup. That's why the gassy smell, the low idle, and the condensation. Richer cars give more condensation. After it warms up a little it straightens out a little because it can handle the fuel a little better when warm (warm fuel is easier to atomize) but I bet if ya checked by doing the math the fuel mileage is low for an L-98. I never cared much for remanned injectors because I found out what they do when they do that. I would definately look into the cold start INJECTOR though...... it may be dripping a little more than it needs to and I would run a fuel pressure check and leakdown check. :seeya
