New Life for a truck passed its prime

[flattopwill]

Maf is hooked up. Mufflers hooked up. Still running very rough but it's getting better. It got better after I drove it round the block but still bad. On the adventure around the block it died like 20 times cause it dies every time I let of the gas. Dunno what to do. Maybe the PCM needs to learn? If that's the only thing wrong with it then it's learning very very slow.

[flattopwill]

Well its definitely getting better. I drove it around the block some more and it seems the more I drive it the better it gets. Ill be suprised if the computer learning is the only problem. It has learned a lot and come a long way but still has a LONG way to go before it has any driveability. I dont have the scanner to look at the fuel trims or O2s anymore but it is definitely still very rich.

Also, I half-ass tried the "Idle Learn Procedure" listed in the Tuning section but my A/C isnt hooked up to the pcm. At least not that I know of. And I dont have a compressor which probably doesnt matter but still.

[keniff]

congrates im glad you got it on the road man, mine should be turning over tomorrow (Monday) i need a new battery an then the Tune. did you stay with a 2.5" exhaust or did you go 3"?
im running a 3" Y into a 3" flex with a bullet/magnaflow combo turned down by the axle. i want it to have a mean sound but at the same time not wake my neighbors like my CC does lol.

i didnt know you got the flex plate/spacer so cheap moat people want 100 just for the flex plate an only god knows for the spacer.

find you a set of used 3:73s an throw in there i wish i was closer i wanna race now

[flattopwill]

Ya I'm doin 3" y-ed into a single Flowmaster

Well it's no where near ready to race. It barely drives. I still wanna know what the problem is.

[keniff]

timing gear lined dot to dot with the crank gear for the timing chain? if its so far off itd run like poo. uh o2s arent working correctly. uh did you try u plugging MAF to see if thats the problem? are you getting a studder ou of it with a back fire or itll barely throttle up with light back fires?

i understand you saying it wont stay running but by that whats it actually doing? i sure wish you had the scanner to see exactly what its giving you an maybe someone with more knowledge can help.

oh pull a plug an see if they are geting burnt up, an recheck the grounds. sounds dumb but could have a loose wire, pinched wire.

[flattopwill]

timing gear lined dot to dot with the crank gear for the timing chain? if its so far off itd run like poo. uh o2s arent working correctly. uh did you try u plugging MAF to see if thats the problem? are you getting a studder ou of it with a back fire or itll barely throttle up with light back fires?

i understand you saying it wont stay running but by that whats it actually doing? i sure wish you had the scanner to see exactly what its giving you an maybe someone with more knowledge can help.

oh pull a plug an see if they are geting burnt up, an recheck the grounds. sounds dumb but could have a loose wire, pinched wire.

I made sure to line up the timing gear dot to dot and I think if I hadnt it wouldnt even run this well. Its just rich as hell. Not sure whats goin on with the O2s but they are brand new Bosch O2 sensors. We put mufflers on it so the O2s being so close to the end of the header shouldnt be a problem anymore. I first started the truck without the MAF but it didnt seem to make a difference when I put a brand new MAF on.

It doesnt really studder it just doesnt want to start and doesnt want to idle and wont handle a load very well. Also it doesnt want to idle after I rev it. Usually it surges and dies after I rev it. BUT, thats one of the things that got better last night when I was driving it around the block. I know the surging usually points to a vacuum leak but Ive checked for vacuum leaks and doesnt even seem like a vacuum leak type of surge. It does backfire a bit now that mufflers are on it.

Ill take a vid of it tonight to let yall see everything its doing. Also, my friend is bringing his scanner back over so we will be able to see what the sensors see again. I kinda thought with the info I posted on here from the scanner that some of the experts on here could tell me whats going on or atleast tell me what sensor is way off but Ive gotten no help. 93 views of my thread in the tuning section and only one reply.

Ill pull plug and check the ground tonight but I dont have to pull a plug to know that its stupid rich. I can tell by the smell and smoke. My friend Ed who is a service manager at a local GM service center said after hearing of the fuel trims that its the most rich that the computer can compensate for.

[flattopwill]

Well, looks like we figured it out. The mufflers were put on halfass just to make it work and it looks like one got sealed well but the other didnt. The short term fuel trims now show -3% on bank 1 and 45% on bank 2. And it kinda sounds dumb but if you look and listen closely you can tell one side of the motor is running good and the other is struggling. Permanent exhaust is going on either tomorrow or the next day and then the motor should be good to go.

The trans is a different story. It moves the truck but the computer is showing codes that would only be for a 4l60e and the trans that is in it is a 4l80e. I am awaiting reply from Allen to check which trans tune he put in.

BTW, sorry for my rant earlier. I was just very frustrated.

[RedHeartbeat]

refresh me on what wiring harness you have. If it is a 60e harness plugged directly into an 80e it will act retarded. Did the harness originally have two speedometer sensor connector for the 80e? If you have the 60e harness you would have to repin the main connector and add an ISS connector or add an 80e conversion adapter and a front input speed sensor connector.

[farmtruc]

I'll check your tune form and calibration today and let you know, if the trans is setting codes, I would drive it until we figure it out.

[flattopwill]

I have a 60e harness. My friend Tim repinned the main connector for 4l80e configuration. He said that I only needed one speed sensor? The trans is definitely acting retarded and inconsistent.

Allen, you say you WOULD drive it?? Im not sure it would drive if I wanted to. Tim said that it wouldnt drive right. He said somethin about not having downshift and TC lockup. ??


Oh and I forgot, we got the speedo, tach, cooling fan and SES light hooked up. After taking out the gauge cluster it was still very hard to access the wires for the gauges. For the speedo we just spliced in the old VSS wires (1 purple w/white and 1 green w/black intertwined) with the new VSS wires. For the tach, we just sent the rpm signal from the new ecm to the coil signal wire from my aftermarket Sunpro tach. Ive read that aftermarket tachs have to be set to 4 cylinder mode to correctly recieve the rpm signal from the new ecm but I didnt change anything on my tach and it works fine. For my cooling fan we hooked it up so that I can turn on a switch to turn it on or leave the switch off and let the ecm turn it on at the correct coolant temp. For the SES light we just ran the wire from the new ecm to the SES light wire from the old harness. Since it was hard to get to the wires behind the cluster we just found the right wire (using an ecm connector diagram) on the old ecm connector, cut it off and connected the new SES wire. BTW, the SES wire is pin A10 brown on the A connector for the old ecm. Still have to configure cruise control.