Possible "follower" problem?

[Paul Workman]

Keep in mind that I'm new to the ('90) LT5...

I may have been maligning the injector(s) for my occational rough idle. Yesterday I noticed a faint "ticking" sound that was in sync with the one cylinder that was not exactly missing, but just not running smooth.

Perhaps it will work itself out...I hope. Fortunately it doesn't do it all the time, and when it does, it goes away after it warms up good, or after a quick 7000 trip thru a couple gears. (I've rounded up a fuel pressure gauge and am poised to do a leak down test. However, I checked w/ the dealer where I bought it, and they confirmed it as 16 new injectors. Yeah, I know. Trust...But, verify!)

Which raises a question...(I almost hate to ask)...How much trouble is it to change one??? (Gosh...I hope there is simple solution to a sticking "lifter" (follower).

While I'm at it, and y'all don't mind another question, I am wondering about the cranking characteristic of these LT5s: The starter rolls quickly over what sounds like several compression strokes, maybe 4-5 rapidly, and then it is as tho it drags on one cylinder (starter RPM drops quite noticably) before resuming its normal quick cranking speed. (I'll try to describe it this way.. It makes a sound like, ye-ye-ye-ye-yer-ye-ye-ye-ye-yer-ye-ye-ye-ye-yer...) When it is cold (beit 40º or 3ºF so far) it runs thru 3 "yer" cycles - about 3 seconds of cranking before it fires. Is this typical? It has me .

Neither of these items are putting my panties in a wad. They just make me wanna say Hmmmmm...for now. But, I've got all winter to tinker if need be and I just thought I'd ask the experts here what comes to mind on these (I won't call them "issues") things.

TIA,

P.

[tomtom72]

Okay, I'll try to offer something........till Jeff sees this!

Starter behavior......check the battery, if it isn't up over 12v @ rest then it may be the root. Seems these cars need a resting state over 13.?+ volts for the car to be happy. Secondly, all the wiring that is obvious in the starter circuit for corrosion and looseness. Third, it is a characteristic of our ignition system for the motors to crank for a long time before firing. It seems that it takes a few revolutions for the electronics to orient themselves....know where I think #6 cyl is...I may be wrong on the cyl #...but it takes awhile before a spark is sent because of this "searching for the right cyl" thing. Tyler Townsley has some great stuff on our ignition systems here. Remember our stuff is primative, now vs the modern stuff, but was out there back when.

Ticking in time with a particular cylinder could be yes the lifter looosing it's prime. It could be that the oil seal is weak or stiff and that could prodouce the ticking that goes away with time & operating temp. I would ask if you kno what kind of injectors the dealer used in the r & r job? I would not think that the OEM disc type would make a ticking noise. I am fairly certain that my RC's in my 90 as they are Lucas derrived can make a ticking as the pintel closes & opens.

I would venture a guess that changing out one lifter is fairly major surgery. Re-timming the cams on that bank & all. Ugh, I would be lost if I had to do that job....so I'll keep my mis-information to myself!


Tom

[HIZNHRZ]

Not sure how close you are to Marc Haibecks shop but you have to be closer than I am. I spent 2 years tinkering over similiar "nagging" type problems. I finally decided to hire an expert.

I'd drive the car over to Marc's and get his opinion. He's great about offering useful advice, even if you are determined to fix it yourself.

Changing one injector is do-able but I'm not sure I would take that approach. If the injectors are new, it's not out of the question but highly unlikely that one is bad. Perhaps someone smarter than I can offer an opinion on this.

Visually, there is a clear difference between Lucas injectors and the OE versions. I still have my (bad) OE injectors. I'd be happy to give you one for comparison. Since it's winter and if you don't use the car as a DD, you might consider removing the plenum (Marc sells a detailed DVD on the how too's) and see if your injectors are OE. If they are, I picked up a set of Accel injectors from Marc and had them in 2 days (he keeps several sets in stock). I got some expert help for Aurora40 and they were changed out in a day. If they are OE, I'd highly recommend changing them out. After tearing apart an OE injector, there is clearly a metallurgic incompatibility condition taking place. I don't know the cause but I'm working on it.

The only problem I found is while my car only has 10K miles it still is 16 years old. I had two vacuum leaks I just could not find. It took Marc about an hour.

[Paul Workman]

Originally Posted by tomtom72

Okay, I'll try to offer something........till Jeff sees this!

Starter behavior......check the battery, if it isn't up over 12v @ rest then it may be the root. Seems these cars need a resting state over 13.?+ volts for the car to be happy. Secondly, all the wiring that is obvious in the starter circuit for corrosion and looseness. Third, it is a characteristic of our ignition system for the motors to crank for a long time before firing. It seems that it takes a few revolutions for the electronics to orient themselves....know where I think #6 cyl is...I may be wrong on the cyl #...but it takes awhile before a spark is sent because of this "searching for the right cyl" thing. Tyler Townsley has some great stuff on our ignition systems here. Remember our stuff is primative, now vs the modern stuff, but was out there back when.

Ticking in time with a particular cylinder could be yes the lifter looosing it's prime. It could be that the oil seal is weak or stiff and that could prodouce the ticking that goes away with time & operating temp. I would ask if you kno what kind of injectors the dealer used in the r & r job? I would not think that the OEM disc type would make a ticking noise. I am fairly certain that my RC's in my 90 as they are Lucas derrived can make a ticking as the pintel closes & opens.

I would venture a guess that changing out one lifter is fairly major surgery. Re-timming the cams on that bank & all. Ugh, I would be lost if I had to do that job....so I'll keep my mis-information to myself!


Tom

Thanks for the replys!

I suspected the LT5 starting characteristic was "normal" for the exact reasons you stated, but wanted to be sure. (The Opti-spark on my '95 LT1 would tend to spoil me rotten! It fired up on the first or second cylinder hit, warm or after sitting in winter cold for weeks!)

The battery checks out good.

Thanks,

P.

P.

[Paul Workman]

Originally Posted by HIZNHRZ

Not sure how close you are to Marc Haibecks shop but you have to be closer than I am. I spent 2 years tinkering over similiar "nagging" type problems. I finally decided to hire an expert.

I'd drive the car over to Marc's and get his opinion. He's great about offering useful advice, even if you are determined to fix it yourself.

Mark's shop is only an hour away which is "close", by Chicago drive time standards. I need to catch my breath (financially) as I just bought the Z, and just put $1400 worth of new skins on her. But, I'm already scheming ways to afford the P&P and head work, plus the SSW headers...Gotta keep up with the "Jones'" (aka C6s) doancha know! If these items don't become full blown issues before then, I'll have Mark take a look at it then, if he will.

Thanks for the tip(s).

P.