LT5 miss at all speeds - Page 2 - ZR-1 Net Registry Forums

Jagdpanzer · 06-17-2015

I like the MSD 8224 DIS coils.
Not that I notice any improved performance, I just like their red color
http://www.msdignition.com/Products/...wer_Style.aspx

Billy Mild · 06-17-2015

I bought mine from Advance Auto Parts. You can get MSD brand from them and usually have coupon deals to bring the cost down.

efnfast · 06-17-2015

Jerry supports the group. Buy them from Jerry.

Mystic ZR-1 · 06-17-2015

A couple months ago, I got 4 new AC/Delco coils from Amazon $100 and a few cents delivered.

Billy Mild · 06-17-2015

Quote:

Originally Posted by Mystic ZR-1

A couple months ago, I got 4 new AC/Delco coils from Amazon $100 and a few cents delivered.

DANG. That is a good deal. I paid a little more for the BWD brand.

Big D · 06-22-2015

Ok everyone, Got the plenum off with no problem. Way easier then what I had imagined with all the good info on the Registry. Took about 40 minutes and broke nothing. However, I tried a suggested method for anti-freeze removal, just drain the plenum, and I would not advise that method. After releasing the plenum, antifreeze began bubbling up from the two holes in the injector housing. Plugged the holes quickly and then drained the radiator. Saving ten minutes at first cost me hours in cleanup. Dang, I hate antifreeze. The valley was extremely clean, prior to the antifreeze dump and all connectors and hoses are in very good shape. Well, at least I know the valley drain works just fine.Tested the wires and they come in at 7.5-9 K ohms for all, well within spec. Also checked the coils, all 4 coil resistance within spec. Also did a visual of the coils and they all look good, no signs of heat deterioration or cracking so I am going to let them go and just change out the injectors. I may end up regretting this decision but I was going to go with stock coils anyway so I don't see the advantage at this point. This is a very low mileage car. Looking forward to installing the new FIC injectors and getting her back on the road.

Big D
69 L46, M21
90 ZR1
95 Suzuki 1200 Bandit
2014 Triumph Thruxton

Dynomite · 06-22-2015

Never heard of draining the coolant from the plenum

I would suggest blocking those two coolant passages in injector housings. That would then be an end to any messing with coolant when removing Plenum.

Oh. Just make sure when you get Plenum back on and coolant refilled that the two Injector Housing Coolant Manifolds are getting warm within a minute of firing up the engine

IMZZ · 06-27-2015

I'll be doing the same thing this week. Let us know how everything turns out. Let me know what you think of the FIC injectors.

Big D · 06-29-2015

got the new FIC injectors in. So far so good. They look high quality and I think they will do the trick. Ordered them on Tues, got them Weds. Easy install. I released the old injectors from the fuel rails first and then removed them from the injector housings. Watch for fuel leaks. Have rags available. Seemed to be the easier way. Then installed the new injectors to the fuel rails and then installed them into the injector housings. All went together real easy. Taking your time is the best advice and follow all of the good info on this site. Helped tons. Took it out for a test beat and it screamed to 6500. Like a whole different car. I do have one problem, I have a slight miss when at idle or just idling down the road. Anything off idle up to floored and it doesn't miss at all. Wasn't able to get new plugs for it on Sunday so I had to re-install the old ones. Hoping maybe it is a bad plug. Didn't have time to troubleshoot any further either. All coils and wires checked out within specs. Won't be able to get back to it until next weekend.

Big D · 07-17-2015

hi everyone, couldn't figure out the miss so i put in new coil packs, wires and plugs. Still missing at low idle and while idling down the road. Also, get a bad hesitation off idle. Still screams to 7 grand though. So tonight, after putting the new plugs in, i have isolated the miss to number 6. Pulled the wires on all other plugs and the idle changes noticeably except for number 6. Pulled the #6 plug and it is bone dry, never saw any fuel in the short time it was running. The injector ohms out correct. Fuel pressure is good also, holds after shutdown. Could the new primary injector at # 6 be questionable?

06-17-2015	#11
Jagdpanzer Join Date: Apr 2007 Location: Northern VA Posts: 2,651	Re: LT5 miss at all speeds I like the MSD 8224 DIS coils. Not that I notice any improved performance, I just like their red color http://www.msdignition.com/Products/...wer_Style.aspx __________________ Phil Wasinger 1994 Torch Red ZR-1 WAZOO Member George Braml Intake

06-17-2015	#12
Billy Mild Join Date: Aug 2014 Location: Kansas City, MO Posts: 838	Re: LT5 miss at all speeds I bought mine from Advance Auto Parts. You can get MSD brand from them and usually have coupon deals to bring the cost down. __________________ Looking for a ZR-1 1985 Yamaha RZ350-NOT STOCK 1971 Yamaha AT1-Middle of a restoration

06-17-2015	#13
efnfast Join Date: Nov 2011 Location: Dunbarton NH Posts: 7,334	Re: LT5 miss at all speeds Jerry supports the group. Buy them from Jerry.

06-17-2015	#14
Mystic ZR-1 Join Date: Jan 2010 Location: Mystic CT Posts: 2,616	Re: LT5 miss at all speeds A couple months ago, I got 4 new AC/Delco coils from Amazon $100 and a few cents delivered.

06-22-2015	#16
Big D Join Date: Jun 2014 Location: Washington state Posts: 17	Re: LT5 miss at all speeds Ok everyone, Got the plenum off with no problem. Way easier then what I had imagined with all the good info on the Registry. Took about 40 minutes and broke nothing. However, I tried a suggested method for anti-freeze removal, just drain the plenum, and I would not advise that method. After releasing the plenum, antifreeze began bubbling up from the two holes in the injector housing. Plugged the holes quickly and then drained the radiator. Saving ten minutes at first cost me hours in cleanup. Dang, I hate antifreeze. The valley was extremely clean, prior to the antifreeze dump and all connectors and hoses are in very good shape. Well, at least I know the valley drain works just fine.Tested the wires and they come in at 7.5-9 K ohms for all, well within spec. Also checked the coils, all 4 coil resistance within spec. Also did a visual of the coils and they all look good, no signs of heat deterioration or cracking so I am going to let them go and just change out the injectors. I may end up regretting this decision but I was going to go with stock coils anyway so I don't see the advantage at this point. This is a very low mileage car. Looking forward to installing the new FIC injectors and getting her back on the road. Big D 69 L46, M21 90 ZR1 95 Suzuki 1200 Bandit 2014 Triumph Thruxton

06-22-2015	#17
Dynomite Join Date: Aug 2009 Location: South Dakota/California Posts: 3,791	Re: LT5 miss at all speeds Never heard of draining the coolant from the plenum I would suggest blocking those two coolant passages in injector housings. That would then be an end to any messing with coolant when removing Plenum. Oh. Just make sure when you get Plenum back on and coolant refilled that the two Injector Housing Coolant Manifolds are getting warm within a minute of firing up the engine __________________ Left Clickable links -Solutions- LT5 Modifications/Rebuild Tricks Low Mileage ZR-1 Restoration 1990 Corvette (L98) Modifications LT5 Eliminated Systems LT5 Added Systems LT5/ZR-1 Fluids 1995 LT5 SPECIFIC TOP END REBUILD TRICKS Last edited by Dynomite; 06-22-2015 at 09:21 PM.

06-27-2015	#18
IMZZ Join Date: May 2015 Location: Oregon Posts: 32	Re: LT5 miss at all speeds I'll be doing the same thing this week. Let us know how everything turns out. Let me know what you think of the FIC injectors. __________________ Ken "IMZZ" 1991 ZR-1 Corvette 1990 MX-5 Miata

06-29-2015	#19
Big D Join Date: Jun 2014 Location: Washington state Posts: 17	Re: LT5 miss at all speeds got the new FIC injectors in. So far so good. They look high quality and I think they will do the trick. Ordered them on Tues, got them Weds. Easy install. I released the old injectors from the fuel rails first and then removed them from the injector housings. Watch for fuel leaks. Have rags available. Seemed to be the easier way. Then installed the new injectors to the fuel rails and then installed them into the injector housings. All went together real easy. Taking your time is the best advice and follow all of the good info on this site. Helped tons. Took it out for a test beat and it screamed to 6500. Like a whole different car. I do have one problem, I have a slight miss when at idle or just idling down the road. Anything off idle up to floored and it doesn't miss at all. Wasn't able to get new plugs for it on Sunday so I had to re-install the old ones. Hoping maybe it is a bad plug. Didn't have time to troubleshoot any further either. All coils and wires checked out within specs. Won't be able to get back to it until next weekend.

07-17-2015	#20
Big D Join Date: Jun 2014 Location: Washington state Posts: 17	Re: LT5 miss at all speeds hi everyone, couldn't figure out the miss so i put in new coil packs, wires and plugs. Still missing at low idle and while idling down the road. Also, get a bad hesitation off idle. Still screams to 7 grand though. So tonight, after putting the new plugs in, i have isolated the miss to number 6. Pulled the wires on all other plugs and the idle changes noticeably except for number 6. Pulled the #6 plug and it is bone dry, never saw any fuel in the short time it was running. The injector ohms out correct. Fuel pressure is good also, holds after shutdown. Could the new primary injector at # 6 be questionable?