car pulsates under load when in power mode

[zr1man@yahoo.ca]

Originally Posted by Mahogaraunch

I have the exact problem with mine! I have a 1990 ZR1 with 11,000km on it which was recently brought up from Florida. Needless to say, I got it out on the road after a long Ontario winter to find under the normal load the car drives perfectly. Under full power, the car shudders and there is no performance difference.

I have it going in this Monday for service, but I am not confident my garage has worked on a ZR1 before. What does anyone think the repair price for the injectors may run me? Does anyone have reservations about bringing a ZR1 to any garage? I am near the Peterborough area and am unaware of Corvette service shops in the area.

Thanks for the input.

Ive got a guy here in Bancroft (1hr away from Peterborough) that I trust to work on my ZR1 and going to use to help me re and re the plenum and install the injectors and coils. He is a perfectionist but not familiar with the lt-5. I think between this website for guidance and trouble shooting, and a skilled perfectionist like himself that I can use to help me do the install, we should be fine. Ill let you know how we make out with mine and if you want I can give you his number....he could come to Peterborough and give you a hand in your garage.

Also, in my travels i noted a Corvette specialty garage on the 401 somewhere between Oakville and cambridge...not sure where exactly but it was called Grand Sport Corvettes. Might be worth giving them a call and asking if they do service on lt5's.

[batchman]

Just to chime in and suggest starting with something easy. I didn't believe it could be this simple, but someone here insisted and they were absolutely right.

Tighten the battery connections.

Worth a shot. You will need the other stuff anyway, but it seems the 2ndary fuel pump and injectors are a significant electrical hit and these side terminal batteries are marginal at best.

Best of luck,
- Jeff

[Mahogaraunch]

Originally Posted by zr1man@yahoo.ca

Ive got a guy here in Bancroft (1hr away from Peterborough) that I trust to work on my ZR1 and going to use to help me re and re the plenum and install the injectors and coils. He is a perfectionist but not familiar with the lt-5. I think between this website for guidance and trouble shooting, and a skilled perfectionist like himself that I can use to help me do the install, we should be fine. Ill let you know how we make out with mine and if you want I can give you his number....he could come to Peterborough and give you a hand in your garage.

Also, in my travels i noted a Corvette specialty garage on the 401 somewhere between Oakville and cambridge...not sure where exactly but it was called Grand Sport Corvettes. Might be worth giving them a call and asking if they do service on lt5's.

I noticed when you quoted the part # from Summit for the secondaries, that the part appeared to be primaries only. I called Summit and the only secondaries they stated they had were for $180 per injector. Not sure if this part you quoted would work as secondaries?

Sorry guys, im not a handy tech guy like you all seem, and doing this job myself is out of my league by a long stretch. The references to Ohm's do confuse me. I have a good rapport with my garage in town but they have not worked on an LT5 before. I'm really not sure where to turn next as I brought the car to the garage and had the fuel filter replaced, the throttle body cleaned, and some injector cleaner placed in the tank. They thought if I drove it for a bit it would correct the problem. I took it out for a drive but as the weather has been crap have not had an opportunity to really drive it. I can hear the vaccuum pump running for several seconds when I turn the key to the accessory position, so that would not appear to be the problem.

Not sure if I want to invest $1400 for a set of 8 secondaries plus however long it takes the garage to install it without knowing for sure thats my problem with the car. With everything I read on this board I am confident the secondaries are my problem, but just not 100% sure.

Thanks for any input you guys have.

[jrd1990zr1]

Originally Posted by Mahogaraunch

I noticed when you quoted the part # from Summit for the secondaries, that the part appeared to be primaries only. I called Summit and the only secondaries they stated they had were for $180 per injector. Not sure if this part you quoted would work as secondaries?

Sorry guys, im not a handy tech guy like you all seem, and doing this job myself is out of my league by a long stretch. The references to Ohm's do confuse me. I have a good rapport with my garage in town but they have not worked on an LT5 before. I'm really not sure where to turn next as I brought the car to the garage and had the fuel filter replaced, the throttle body cleaned, and some injector cleaner placed in the tank. They thought if I drove it for a bit it would correct the problem. I took it out for a drive but as the weather has been crap have not had an opportunity to really drive it. I can hear the vaccuum pump running for several seconds when I turn the key to the accessory position, so that would not appear to be the problem.

Not sure if I want to invest $1400 for a set of 8 secondaries plus however long it takes the garage to install it without knowing for sure thats my problem with the car. With everything I read on this board I am confident the secondaries are my problem, but just not 100% sure.

Thanks for any input you guys have.

I had similar problems with both my 1990s. Was bad secondary injectors caused by the E10 in gas.

FWIW, I bought a set of 16 injectors from Jon Banner (Fuel Injector Connection) for under $400. http://fuelinjectorconnection.com/shop/

http://www.corvetteinjectors.com/sho....php?groupid=3

Replaced them myself. I am definately not a tech guy. This was the first time I ever tried to do a repair such as this. If you use the instructions here on the registry and have a new set of primary o-rings and a spare set of plenum gaskets from Jerry's gaskets the job isn't that difficult. http://jerrysgaskets.com/store2/root/

Just make sure to drain the coolant down enough and use the procedure to refill coolant. This is probabily the most difficult part.

[A26B]

Awhile back, I started making up gasket & seal kits for the most commonly done procedures, in response to many emails asking "What all do I need?". Here's a link for the Fuel Injector Maintenance Kits, 90~92. The only choice you need to make, pertains to which type of seals you want.

Basically, Buna-N is best for 100% gasoline and also happens to be the least expensive. Viton is the best for Ethanol/Gasoline blends, but is more expensive.

90~92 Buna-N kit
http://jerrysgaskets.com/store2/root...roducts_id=458

90~92 Viton kit
http://jerrysgaskets.com/store2/root...roducts_id=459


Please note that virtually all new injectors come with o-rings installed already. That particular o-ring seal is PN1712222. If you are using new injectors, save some $'s, refer to the kit contents list on the website & get everything separately, except the 17112222 o-ring seals.

[zr1man@yahoo.ca]

Originally Posted by Mahogaraunch

I noticed when you quoted the part # from Summit for the secondaries, that the part appeared to be primaries only. I called Summit and the only secondaries they stated they had were for $180 per injector. Not sure if this part you quoted would work as secondaries?

Sorry guys, im not a handy tech guy like you all seem, and doing this job myself is out of my league by a long stretch. The references to Ohm's do confuse me. I have a good rapport with my garage in town but they have not worked on an LT5 before. I'm really not sure where to turn next as I brought the car to the garage and had the fuel filter replaced, the throttle body cleaned, and some injector cleaner placed in the tank. They thought if I drove it for a bit it would correct the problem. I took it out for a drive but as the weather has been crap have not had an opportunity to really drive it. I can hear the vaccuum pump running for several seconds when I turn the key to the accessory position, so that would not appear to be the problem.

Not sure if I want to invest $1400 for a set of 8 secondaries plus however long it takes the garage to install it without knowing for sure thats my problem with the car. With everything I read on this board I am confident the secondaries are my problem, but just not 100% sure.

Thanks for any input you guys have.

now you have me wondering if i bought the right injectors from summit racing? i got the part number from this reference by a zr1 specialist.
http://www.zr1specialist.com/HAT%20W...eplacement.pdf

he states that accel 150821 is a dirrect fit for the 91 zr1 and he uses this brand often on customers vehicles.

Can anybody confirm if purchased the right injectors for my secondary injectors? acc-150821 8-pack 21 lb/hr $300 from summit.

[lbszr]

Originally Posted by Mahogaraunch

I noticed when you quoted the part # from Summit for the secondaries, that the part appeared to be primaries only. I called Summit and the only secondaries they stated they had were for $180 per injector. Not sure if this part you quoted would work as secondaries?
Thanks for any input you guys have.

I don't know which ones those are, but 150121 $40 each from summit 21# is what I used for prim. and sec. 8 Of them need a plastic tab removed so the electical connector will plug in, forget whether it was sec. or pri.

I would have to look, but I thought mine were yellow though.

[lbszr]

Originally Posted by zr1man@yahoo.ca

http://www.zr1specialist.com/HAT%20W...eplacement.pdf

he states that accel 150821 is a dirrect fit for the 91 zr1 and he uses this brand often on customers vehicles.

Can anybody confirm if purchased the right injectors for my secondary injectors? acc-150821 8-pack 21 lb/hr $300 from summit.

That website is as good as the factory maintance manual. Looks like the same as 150121, only packaged with 8 and saves a little money.

[Mahogaraunch]

Well, just ordered a set of 16 from Corvetteinjectors and the gasket set from jerry'sgaskets..

Anything else I need that anyone can think of? Spoke to my shop and they quoted about 3.5 hours to do the job.

Thanks.

[zr1man@yahoo.ca]

just installed the parts i had mentioned before...secondary injectors and coil packs and it fixed the car! thanks guys for all the help and now i can enjoy the extra 200hp