1992 ZR1 Seems Sluggish

[KJL]

Happy to hear it worked out. I realized I have an Autoxray 6000 so I did a scan and the O2 sensors seemed to be reading like they are supposed to and cycle between .1 and .9 volts. The TPS ramps from .54 to 4.6 volts. Still having power issues. Now stumbles a bit upon acceleration. Next I will check the coil pack resistance which seems simple enough at the ECM harness and perform a fuel pressure test on both the primary and secondary pumps. If those turn out to be OK, my guess will be the injectors.

What is Wazoo?

[KJL]

Update:
Engine also seemed very hot tot he touch and running a bit on the hot side. The dip stick was so hot I couldn't even hold it. Both my valve cover emblems also came off although they seemed like they were in the process of doing so regardless. I am traveling this week and look forward to seeing how the fuel pump tests pan out.

[KJL]

I just finished checking some things and found the following:
Cyl 3 Primary Injector: 6.1 ohms
Cyl 5 Primary Injector: 9.9 ohms
Cyl 8 Secondary Injector: 9.9 ohms

All others 12.2 to 12.6 ohms

Coil Packs Secondary with Plenum installed cold:
1/6: 20.5 ohms
2/3: 20.8
4/7: 18.2
5/8: 20.6

FP-1: 40 psig
FP-2: 40 psig

AND, what ever GM engineer thought it was a good idea to put fuse blocks up under the passenger side dash with no access doors need to be fired. If he has already retired, they need to re-hire him so they can fire him.
KJL is offline Reply With Quote

[Paul Workman]

Originally Posted by KJL

I just finished checking some things and found the following:
Cyl 3 Primary Injector: 6.1 ohms
Cyl 5 Primary Injector: 9.9 ohms
Cyl 8 Secondary Injector: 9.9 ohms

All others 12.2 to 12.6 ohms

Coil Packs Secondary with Plenum installed cold:
1/6: 20.5 ohms
2/3: 20.8
4/7: 18.2
5/8: 20.6

FP-1: 40 psig
FP-2: 40 psig

AND, what ever GM engineer thought it was a good idea to put fuse blocks up under the passenger side dash with no access doors need to be fired. If he has already retired, they need to re-hire him so they can fire him.
KJL is offline Reply With Quote

As suspected, the injectors are NOT alcohol tolerant. Highly recommend you get the new, stainless injectors; the ZR-1 "kit" from Jon at FIC - he knows what you need, AND the kit includes gaskets and O-rings from Jerry's Gaskets.

Do you have an FSM? If NOT, my I suggest you contact WVZR-1 (Dave). He can provide you with a full .pdf file for, IIRC, $26. Ya can't beat that!

[KJL]

Thanks for the info. I def need a manual. I have a BISHKO CD for my 95 that is quite nice as well. Interestingly the car has been running better. I know the bad injectors still function but just not very well. I guess I will need to replace them this fall. The car is mostly stock with the cat-back Flow master system. Was thinking if I remove the plenum, I may as well do some porting and have Marc upgrade the chip. Now that it is exempt from emissions, was also thinking about removing the secondaries. Who does good porting at decent price? I know Marc offers that service and I am sure it is an amazing work of HP increasing art when he is done but I cant afford him at the moment. I just had him upgrade my 95 rear diff to 4.10's.

[Paul Workman]

Originally Posted by KJL

*...I know the bad injectors still function but just not very well. I guess I will need to replace them this fall. ...*

You might want to re-think that injector replacement schedule, especially if you are going to be driving the car in the interim!

I had a burnt valve in one of my cylinders that also had a bad primary injector.

It would idle a little rough, and die while idling sometimes. And, it too seemed to run best at moderate to WOT.

What do the knock counts look like? IF in fact the injector is not delivering enough fuel, resulting in a lean condition and knocking (and you don't always hear knocks), the ECM could be backing timing off - which would also make it seem sluggish! What is the timing at cruise?

[KJL]

That is a great observation and seems to make perfect sense to me. I guess my obd would tell me what the timing is a cruise. Although I am going to change out the injectors at this point regardless. I will also check the knock count.