Back to the 93 Gmc with the rattle

348tripower · June 05, 2012, 05:20:12 PM

I went back thru everything again. Seems I didn't reconnect the timing wire after setting the base timing. Big dummy. I re timed it and hooked up the wire. Cleared the check engine code but I have a TCC not unlocked and a high trans temp code now. I am thinking that the spark knock I am getting now is due to the converter not unlocking. I still have a rough idle and I don't know if they are related. Idle rmp about 675 in netural 475 to 500 in drive. Any suggestions?
Don

wayne petty · June 06, 2012, 10:20:29 AM

still got that scan tool you used on the L98 TPI motor.??

post some data...

can you check your reluctor for cracks

this is the rebuilt HEI with the far superior pick up and reluctor design..

how about the ignition coil...

can you verify that when you apply vacuum to the EGR valve that the engine stumbles... should die at idle when the EGR is applied... without EGR flow.. when under acceleration.. the system drops into open loop.. programmed fuel control... the lack of the EGR flow causes the oxygen content in the intake charge to be a higher percentage and this requires more fuel the system cannot calculate as its blind in open loop.. so it will ping do to the lean mixture under power..

can you TEE in a vacuum gauge to the hose between the EGR solenoid and the egr valve.. stick it to the windshield and take the truck for a test drive to verify the EGR is being commanded...

the reason i don't want you to test the EGR control solenoid wiring. its just easier to use the vacuum gauge.. to start the trouble shooting.

wayne petty · June 06, 2012, 10:35:30 AM

high trans temp is because the TCC is unlocked and there is too much heat being built up in the converter..

you might also want to take a test drive.. and then aim your infrared temp gun at the pair of lines into and out of the radiator.. see if its actually cooling.. if they are the same temp.. thats bad...

run the infrared along the lines.. perhaps there is no flow..

no flow from the transmission oil cooler will result in a transmission life of almost exactly 15 MILES... this is the amount of distance before the planetary gears have burned up in other overdrive transmissions with ZERO flow..

348tripower · June 06, 2012, 04:08:22 PM

I'll do the vacuum test and check flow later this weekend. Just got a buncch of work to do

I'll post scan data too.

348tripower · June 15, 2012, 10:49:44 AM

Ok fellas. This thing has hardly any oil to the overhead. Should be pumpin oil all over the fender wells. Just a little dribble out of a couple.

This would explain the rough running. Shows 50 lbs on the gauge. Wunder if a cam bearing turned?

348tripower · June 15, 2012, 04:45:53 PM

But, when I get looking I see a groove all the way around the rear cam bearing register. So a turned cam bearing shouldn't caus this. :?

wayne petty · June 16, 2012, 02:48:58 AM

does it have a remote oil cooler...

does it have a remote oil filter.

there is also a bypass valve pressed into the oil cooler adaptor or the block depending on where the filter is...

pickup the oil cooler adaptor gasket kit..

remove the filter.. remove the adaptor... disable the ignition or just do this with the key off...

crank the engine with the filter and or adaptor off.. using the remote starter .. how much oil flow do you get from the pump...

V6 motors.. have a pressed in oil pump pick up tube.. they can fall out.. probably NOT the problem as you show 50PSI..

you might also want to cut the filter open.. to verify that the media is intact...

this has happened on other motors

this is what GM uses to test the LS motors

ITEM 5 is the oil cooler bypass valve... they are around $5 bucks from what i can see online... i might be able to find the part number if you like..

wayne petty · June 16, 2012, 02:57:20 AM

one other thing...

i don't know if your 93 has a electronic EGR valve.. i just worked on a 98 4.3 astro that failed smog with high NOX..

everything pointed toward the EGR.. i used my OTC 4000 with the 98 pathfinder cartridge.. got into the OEM tests.. commanded the EGR open at idle... i got to 80 percent open before the engine stumbled.. at that point it died..

after that .. it worked every time instantly.. i ramped it to 100 and back to 0 a bunch of times..

thats all i did.. flew through the smog test..

while we were test driving after the EGR override testing.. it never got as far as i could see above about 45% open..

it idled a LOT better after words also.. no more spark knock on acceleration..

i realize that not all 93s have digital EGRs.. but its a great use for the scan tool on the later versions..

348tripower · June 16, 2012, 07:46:58 AM

Quote from: "wayne petty"one other thing...

i don't know if your 93 has a electronic EGR valve.. i just worked on a 98 4.3 astro that failed smog with high NOX..

everything pointed toward the EGR.. i used my OTC 4000 with the 98 pathfinder cartridge.. got into the OEM tests.. commanded the EGR open at idle... i got to 80 percent open before the engine stumbled.. at that point it died..

after that .. it worked every time instantly.. i ramped it to 100 and back to 0 a bunch of times..

thats all i did.. flew through the smog test..

while we were test driving after the EGR override testing.. it never got as far as i could see above about 45% open..

it idled a LOT better after words also.. no more spark knock on acceleration..

i realize that not all 93s have digital EGRs.. but its a great use for the scan tool on the later versions..

Code Select




No remote oil filter . Interesting about the EGR. No more testing this weekend. Taking the COE and following the fishing boat to Muskegon. Going to drop it in the drink and do the final tuning. Getting up tomorrow am and headed back to Hastings for a show. Metting the wife and the rest of the crew there.

348tripower · July 04, 2012, 06:46:49 AM

Update on this. I bought a reman long block roller motor and just finished the install. It runs perfectly. I have a lot of customer work to do right now so taking the old motor apart for inspection will have to wait a bit. I will follow up with what I find.

Crosley.In.AZ · July 04, 2012, 10:55:16 AM

Quote from: "348tripower"Update on this. I bought a reman long block roller motor and just finished the install. It runs perfectly. I have a lot of customer work to do right now so taking the old motor apart for inspection will have to wait a bit. I will follow up with what I find.

it will b interesting to see what was banging around insude the block of the old engine :T)