87 lacking uumph
Thread Starter
Instructor
Joined: May 2006
Posts: 182
Likes: 1
From: Metairie Louisiana
87 lacking uumph
Hey Guys,
My 87 seems to be running fine, but doesn't have that power boost that I think it should. I did a complete tune up along with a fuel injection cleaning, but it still feels on the weak side. The car has 81k miles, but does not burn or leak oil. The plugs that came out the car seemed fine with no carbon build up. I see alot of people are changing out their fuel injectors, what injectors would benefit me the most for my stock set up? Any additional ideas would also be appreciated.
My 87 seems to be running fine, but doesn't have that power boost that I think it should. I did a complete tune up along with a fuel injection cleaning, but it still feels on the weak side. The car has 81k miles, but does not burn or leak oil. The plugs that came out the car seemed fine with no carbon build up. I see alot of people are changing out their fuel injectors, what injectors would benefit me the most for my stock set up? Any additional ideas would also be appreciated.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
The lose of power could be a clogged cat/pre cats. As for the injectors, if they are not leaking then don't worry until you get a good bit up in hp. From your description of the spark plugs, sounds like the injectors are in good shape.
Le Mans Master
Joined: Aug 2003
Posts: 9,884
Likes: 3
From: Magnolia Mississippi
St. Jude '03-'04-'05-'06-'07
Stock injectors for Stock setup... but i'd check my fuel pressure first and check the injector pulse to see if you really need new injectors, if you do, Five-O-Motorsports is great. Could be your timings off.
Thread Starter
Instructor
Joined: May 2006
Posts: 182
Likes: 1
From: Metairie Louisiana
Originally Posted by RRT vette
The lose of power could be a clogged cat/pre cats. As for the injectors, if they are not leaking then don't worry until you get a good bit up in hp. From your description of the spark plugs, sounds like the injectors are in good shape.
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
Fuel pressure test is always a good place to start, a noid light comes in handy to check the pulses (most commonly used when a miss is present) but a Digital voltage ohm meter is a must have. You could have weak or bad coils in your injectors..they should be checked both hot and cold and should check out around 16 ohm, plus or minus 1-1.5, very easy test. Two other things, and I could use some help here, but you should be able to pull a vacumn test on the engine, which would give you an indication of the health of your cats..thing is, I can't remember without looking what it is supposed to read, I want to say 21 at idle...hope someone correct me if I'm wrong!
Lastly, I have an 87 with auto with 103,000 miles on her and she still will get sideways on me if I punch her off the line. You may want to try a can of SeaFoam...this stuff works wonders, been using it for years, and alot of guys on the forum now swear by it.
Lastly, I have an 87 with auto with 103,000 miles on her and she still will get sideways on me if I punch her off the line. You may want to try a can of SeaFoam...this stuff works wonders, been using it for years, and alot of guys on the forum now swear by it.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Originally Posted by rick lambert
Fuel pressure test is always a good place to start, a noid light comes in handy to check the pulses (most commonly used when a miss is present) but a Digital voltage ohm meter is a must have. You could have weak or bad coils in your injectors..they should be checked both hot and cold and should check out around 16 ohm, plus or minus 1-1.5, very easy test. Two other things, and I could use some help here, but you should be able to pull a vacumn test on the engine, which would give you an indication of the health of your cats..thing is, I can't remember without looking what it is supposed to read, I want to say 21 at idle...hope someone correct me if I'm wrong!
Lastly, I have an 87 with auto with 103,000 miles on her and she still will get sideways on me if I punch her off the line. You may want to try a can of SeaFoam...this stuff works wonders, been using it for years, and alot of guys on the forum now swear by it.
Lastly, I have an 87 with auto with 103,000 miles on her and she still will get sideways on me if I punch her off the line. You may want to try a can of SeaFoam...this stuff works wonders, been using it for years, and alot of guys on the forum now swear by it.
Thread Starter
Instructor
Joined: May 2006
Posts: 182
Likes: 1
From: Metairie Louisiana
The SES has not been on at all. I have not tested the fuel injectors, but would like to do that asap. I'll have to buy the tester necessary for the task, since I don't have one. Can you provide some info on the tools needed and procedure for checking the injectors or coils?
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Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
To test the injcetors you will need a fuel pressure guage ($40 at a autoparts store) and it connects to the right side fuel rail at the Schrader valve (looks like a tire valve). The cap will have to be unscrewed to screw the fuel pressure guage on. Once it is connected good and tight, turn the key on and observe the pressure (should be about 40 psi), then turn the key off. Watch the guage for about 10 minutes and note if the needle falls and by how much. That tests the FPR, injectors, and check valve. Remove the vacuum on the FPR and note any gas in the line. For the injectors, the fuel return line at the tank will have to be pinched. Do the same as in bold.
To test the injector coils you will need a ohm meter or multimeter ($20 at a autoparts store). Disconnect the injector pigtails and use one lead of the meter on one tooth of injector and same for the other. They should read around 16 ohm each +/- 1 or 2 ohms.
To test the injector coils you will need a ohm meter or multimeter ($20 at a autoparts store). Disconnect the injector pigtails and use one lead of the meter on one tooth of injector and same for the other. They should read around 16 ohm each +/- 1 or 2 ohms.
Thread Starter
Instructor
Joined: May 2006
Posts: 182
Likes: 1
From: Metairie Louisiana
Originally Posted by RRT vette
To test the injcetors you will need a fuel pressure guage ($40 at a autoparts store) and it connects to the right side fuel rail at the Schrader valve (looks like a tire valve). The cap will have to be unscrewed to screw the fuel pressure guage on. Once it is connected good and tight, turn the key on and observe the pressure (should be about 40 psi), then turn the key off. Watch the guage for about 10 minutes and note if the needle falls and by how much. That tests the FPR, injectors, and check valve. Remove the vacuum on the FPR and note any gas in the line. For the injectors, the fuel return line at the tank will have to be pinched. Do the same as in bold.
To test the injector coils you will need a ohm meter or multimeter ($20 at a autoparts store). Disconnect the injector pigtails and use one lead of the meter on one tooth of injector and same for the other. They should read around 16 ohm each +/- 1 or 2 ohms.
To test the injector coils you will need a ohm meter or multimeter ($20 at a autoparts store). Disconnect the injector pigtails and use one lead of the meter on one tooth of injector and same for the other. They should read around 16 ohm each +/- 1 or 2 ohms.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
NOTE: When I stated "do the same as in bold", you will need to prime the pump by turning the key on and then turn the key off and pinch the line directly after. Sorry, no excuse for misleading info.
Burning Brakes
Joined: Aug 2004
Posts: 1,174
Likes: 125
From: Dunstable MA
St. Jude Donor '05
On the topic of a clogged cat. My 87 had a clog in the rear Y-pipe due to the cat. The ceramic had broken up and a big chunk had lodged in the crotch of the Y. The car would decelerate when I would have expected it to coast. It was like that from the time I bought it, and I only discovered it last year when mounting a new cat-back. So I got more HP boost out of installing a new cat-back than I had a right to expect. It seems the same thing can happen if the pre-cats crumble and clog the main cat.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Originally Posted by Rich Silvestris
On the topic of a clogged cat. My 87 had a clog in the rear Y-pipe due to the cat. The ceramic had broken up and a big chunk had lodged in the crotch of the Y. The car would decelerate when I would have expected it to coast. It was like that from the time I bought it, and I only discovered it last year when mounting a new cat-back. So I got more HP boost out of installing a new cat-back than I had a right to expect. It seems the same thing can happen if the pre-cats crumble and clog the main cat.
Originally Posted by CentralCoaster
Until I read your description I thought you had a tampon wedged in there.
Thread Starter
Instructor
Joined: May 2006
Posts: 182
Likes: 1
From: Metairie Louisiana
Just checked all the fuel injectors along with fuel pressure. All injectors are at 17.5 and the fuel pressure holds with no leaks. There is no gas in the lines. While checking the injectors I noticed coolant by a few of the intake bolts, which means the intake gaskets now need to be replaced. I am told that alone is about a 6 hour job.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Originally Posted by my87vet
Just checked all the fuel injectors along with fuel pressure. All injectors are at 17.5 and the fuel pressure holds with no leaks. There is no gas in the lines. While checking the injectors I noticed coolant by a few of the intake bolts, which means the intake gaskets now need to be replaced. I am told that alone is about a 6 hour job.
Thread Starter
Instructor
Joined: May 2006
Posts: 182
Likes: 1
From: Metairie Louisiana
Originally Posted by RRT vette
Indeed it is a 6 hr job. Sounds like the injectors and fuel pressure are good. Did you find out what the problem was?
The car seems to be running better now that the fuel injection cleaner has run through, still has a small miss at idle but not bad at all. Now I need to to focus on that coolant leak, just glad I found it when I did.