Dilemma

[Brillo1990]

Well the temps were really nice for once here so I decided to take the car for a short spin last night but had a problem. I started it up and there was the normal squeaking from the belt or the idler (have to fix that problem) so I took it out on the highway to warm it up good, it ran fine. I stopped at home after the squeaking stopped and upon restarting it, it was like the engine was missing on 2 cylinders. Now at first I was thinking the injectors were acting up but when I changed the power key to normal then back a couple times nothing changed at all there even while driving kicking in the secondaries so I parked it again.

Upon starting it again it still missed so I headed to the garage to park it for the night to check it later. On the way there I switched the key back and forth just for the hell of it and about 2 blocks from the garage it came out of it and ran fine. Now after thinking about it I'm thinking it dropped a coil pack for a short time when it got warm maybe and came out of it, is this possible? I had the coil go bad on my pickup once and it just shut down when it got hot, then ran fine after it cooled off. Since there are 4 coil packs on the ZR-1 it may be possible? I'm thinking I should just pull the plenum now and replace the injectors, coil packs and maybe wires now before it gets any nicer out. Any ideas?

As an afterthought last week while some spirited on ramp entry I did have 2 quick lurches while at half throttle or so but it ran fine for the next 60 miles until I got home. This IS the warmest weather the car has seen since I bought it in January BTW.

[tccrab]

Sorry to be the bearer of bad news.
This is the classic failing injectors symptom and you're absolutely right that you should do the coils and wires while you're in there.
Be sure to check all the secondary vacuum components, PCV valves and hoses.
And don't forget to check/re-torque all the bolts for the injector housings and the oil mist box too.

TomC
'Crabs

Originally Posted by Brillo1990

Well the temps were really nice for once here so I decided to take the car for a short spin last night but had a problem. I started it up and there was the normal squeaking from the belt or the idler (have to fix that problem) so I took it out on the highway to warm it up good, it ran fine. I stopped at home after the squeaking stopped and upon restarting it, it was like the engine was missing on 2 cylinders. Now at first I was thinking the injectors were acting up but when I changed the power key to normal then back a couple times nothing changed at all there even while driving kicking in the secondaries so I parked it again.

Upon starting it again it still missed so I headed to the garage to park it for the night to check it later. On the way there I switched the key back and forth just for the hell of it and about 2 blocks from the garage it came out of it and ran fine. Now after thinking about it I'm thinking it dropped a coil pack for a short time when it got warm maybe and came out of it, is this possible? I had the coil go bad on my pickup once and it just shut down when it got hot, then ran fine after it cooled off. Since there are 4 coil packs on the ZR-1 it may be possible? I'm thinking I should just pull the plenum now and replace the injectors, coil packs and maybe wires now before it gets any nicer out. Any ideas?

As an afterthought last week while some spirited on ramp entry I did have 2 quick lurches while at half throttle or so but it ran fine for the next 60 miles until I got home. This IS the warmest weather the car has seen since I bought it in January BTW.

[Brillo1990]

Thanks Tom I kinda figured I would be doing the injectors and stuff this year, just my luck and the nature of the beast. I tried posting back earlier but I could not stay logged in when I hit reply. I closed the page and started over and it works fine now.

[mike100]

I just finished mine. parked it hot for 40 minutes and it was missing when I drove off. There's a procedure to check inj resistances as installed just in case you want to be absolutely sure before you take it apart.

mine ran a lot smoother after the new set of injectors went in.

[GrayZ]

Originally Posted by Brillo1990

Well the temps were really nice for once here so I decided to take the car for a short spin last night but had a problem. I started it up and there was the normal squeaking from the belt or the idler (have to fix that problem) so I took it out on the highway to warm it up good, it ran fine. I stopped at home after the squeaking stopped and upon restarting it, it was like the engine was missing on 2 cylinders. Now at first I was thinking the injectors were acting up but when I changed the power key to normal then back a couple times nothing changed at all there even while driving kicking in the secondaries so I parked it again.

Upon starting it again it still missed so I headed to the garage to park it for the night to check it later. On the way there I switched the key back and forth just for the hell of it and about 2 blocks from the garage it came out of it and ran fine. Now after thinking about it I'm thinking it dropped a coil pack for a short time when it got warm maybe and came out of it, is this possible? I had the coil go bad on my pickup once and it just shut down when it got hot, then ran fine after it cooled off. Since there are 4 coil packs on the ZR-1 it may be possible? I'm thinking I should just pull the plenum now and replace the injectors, coil packs and maybe wires now before it gets any nicer out. Any ideas?

As an afterthought last week while some spirited on ramp entry I did have 2 quick lurches while at half throttle or so but it ran fine for the next 60 miles until I got home. This IS the warmest weather the car has seen since I bought it in January BTW.

I am not a mechanic, but, symptom's relate to a problem i had a few years ago where the map sensor rubber hose was wore out, and very pliable, replaced it and my woes were cured. might try that first, a 2.00 fix.

where are you in eastern iowa? we caravan to BG every year, i'm in Missery.
you are welcome to meet up with us, if you plan on goin

keith

[Brillo1990]

Originally Posted by mike100

I just finished mine. parked it hot for 40 minutes and it was missing when I drove off. There's a procedure to check inj resistances as installed just in case you want to be absolutely sure before you take it apart.

mine ran a lot smoother after the new set of injectors went in.

Mike do you mean it was missing after you replaced the injectors when it was hot or you replaced them after it was parked hot and was missing?

[Brillo1990]

Originally Posted by ITLGO2

I am not a mechanic, but, symptom's relate to a problem i had a few years ago where the map sensor rubber hose was wore out, and very pliable, replaced it and my woes were cured. might try that first, a 2.00 fix.

where are you in eastern iowa? we caravan to BG every year, i'm in Missery.
you are welcome to meet up with us, if you plan on goin

keith

Keith I sure wish I was going to BG with you guys but I have made plans to go to South Dakota the same time to see all my old bike riding friends. If I could talk the wife into going to BG I would, I think it would be a blast, I also want to go on the Power Tour.

[mike100]

Originally Posted by Brillo1990

Mike do you mean it was missing after you replaced the injectors when it was hot or you replaced them after it was parked hot and was missing?

sorry- clarification-->It ran great after I changed the injectors. I just got this car in January and I pulled the plenum to fix a vacuum leak. That got fixed and I just reassembled it. Soon after that repair, it exibited the hot miss I described above. Then I pulled it all apart again to do the injectors (and port the injector housing and cyl head primaries for the easy hp gains). It's been fine since. A little more oomph on the top end too.