Wierd idle.
Thread Starter
Le Mans Master
Joined: Jan 2010
Posts: 8,553
Likes: 3
Wierd idle.
My 91, L98 has a wierd idle thing.
After warm up, it'll drop maybe 200 rpms, pause/hesitate, then over rev by 200 rpms, the drop back to normal. This sequesnce happens all with-in just a few seconds Only does this at temp.
At either temp, warm/hot or cold, at higher rpms ( over 1500) it doesn't do this.
Sometimes at lower speeds 20-30, I can feel the engine "pulsing" only when I'm just crusing, not aclerating....sorry, best way to describe it.
Any ideas?
Please answer in laymans terms, I'm not that mech inclined and don't know where most, if any parts are...lol/
TY.
Jamenns.
After warm up, it'll drop maybe 200 rpms, pause/hesitate, then over rev by 200 rpms, the drop back to normal. This sequesnce happens all with-in just a few seconds Only does this at temp.
At either temp, warm/hot or cold, at higher rpms ( over 1500) it doesn't do this.
Sometimes at lower speeds 20-30, I can feel the engine "pulsing" only when I'm just crusing, not aclerating....sorry, best way to describe it.
Any ideas?
Please answer in laymans terms, I'm not that mech inclined and don't know where most, if any parts are...lol/
TY.
Jamenns.
Thread Starter
Le Mans Master
Joined: Jan 2010
Posts: 8,553
Likes: 3
Melting Slicks
Joined: Jan 2010
Posts: 2,024
Likes: 4
From: Austin TX
Mine does something similar. I've made sure the air filter, MAF, and TB were clean, IAC was right, and it still idles a bit off. So, as soon as I'm not broke from credit card and car payments, I'm ordering me some Bosch 3's, and taking a weekend off.
Thread Starter
Le Mans Master
Joined: Jan 2010
Posts: 8,553
Likes: 3
Yea, I could order the Bosch 3's, I'd have to have someone put them in, as I'm not gifted.
I just read using injector cleaner will ruin whatevers left of mine ( if thats the prob) if I use it.
Anyone heard of such a thing?
I just read using injector cleaner will ruin whatevers left of mine ( if thats the prob) if I use it.
Anyone heard of such a thing?
Thread Starter
Le Mans Master
Joined: Jan 2010
Posts: 8,553
Likes: 3
This is what I read, from a different place.
BS?
Testing Fuel Injectors:
Get an Ohm meter or VOM meter.
1. Turn on the car
2. Unplug one of the wires from one fuel injectors
3. Connect Ohm Meter lead to connectors on the fuel injector.
Readings should be: 14 Ohms or less for a good injector.
Any reading higher than 14 Ohms indicates
that the fuel injector needs to be replaced
with a new one.
4. disconnect Ohm meter.
5. reconnect wire to fuel injector.
6. Repeat procedure on all eight injectors.
Never use a fuel injection cleaner with the 1990-1991 L-98 engines the cleaner will ruin the injectors.
The injectors usually go bad in series, all of the injectors should be replaced with new according to a Chevrolet Dealer Service center cost is around $1,100 - $1,400 with a lifetime warranty on the new fuel injectors for as long as you own the Corvette.
The Fuel Injectors used by GM in 1990 and 1991 were crap according to a local Chevrolet Service Department. All 1990 - 1991 Chevrolets fuel injectors will need to be replaced due to a poor design.
My former 1990 Corvette with L-98 engine with less than 8,000 miles had gone through 12 fuel injectors within four years.
BS?
Testing Fuel Injectors:
Get an Ohm meter or VOM meter.
1. Turn on the car
2. Unplug one of the wires from one fuel injectors
3. Connect Ohm Meter lead to connectors on the fuel injector.
Readings should be: 14 Ohms or less for a good injector.
Any reading higher than 14 Ohms indicates
that the fuel injector needs to be replaced
with a new one.
4. disconnect Ohm meter.
5. reconnect wire to fuel injector.
6. Repeat procedure on all eight injectors.
Never use a fuel injection cleaner with the 1990-1991 L-98 engines the cleaner will ruin the injectors.
The injectors usually go bad in series, all of the injectors should be replaced with new according to a Chevrolet Dealer Service center cost is around $1,100 - $1,400 with a lifetime warranty on the new fuel injectors for as long as you own the Corvette.
The Fuel Injectors used by GM in 1990 and 1991 were crap according to a local Chevrolet Service Department. All 1990 - 1991 Chevrolets fuel injectors will need to be replaced due to a poor design.
My former 1990 Corvette with L-98 engine with less than 8,000 miles had gone through 12 fuel injectors within four years.
Racer
Joined: Dec 2009
Posts: 298
Likes: 0
From: Reno NV
Bosch 3s from F.I.C. are less then $200 a set w/gaskets. Just watch the video and search a little, Some other members changed thier own. It dont look to hard to do yourself.
Last edited by Millah; Mar 24, 2010 at 10:41 AM. Reason: spelling
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Burning Brakes
Joined: Jan 2001
Posts: 1,218
Likes: 2
From: Plainfield IL
My '86 does the same thing at idle. I cleaned the throttle body with spray cleaner and this helped a little. A mechanic told me the butterfly inside the throttle body had slop in the two ends (pivots), which was allowing air excess air to enter.
You might also check your vacuum hoses and connections to ensure they're tght and not leaking.
You might also check your vacuum hoses and connections to ensure they're tght and not leaking.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
First check for any codes stored in the ECM. Could be many things causing your problem, dirty IAC, vacuum leaks, O2 sensor, dirty throttle body, leaking injector, ect. If you don't feel comfortable working on it, just take it to a good mechanic and see if they can figure it out.
Thread Starter
Le Mans Master
Joined: Jan 2010
Posts: 8,553
Likes: 3
First check for any codes stored in the ECM. Could be many things causing your problem, dirty IAC, vacuum leaks, O2 sensor, dirty throttle body, leaking injector, ect. If you don't feel comfortable working on it, just take it to a good mechanic and see if they can figure it out.
TY