Should I be getting better gas mileage? Improvements?

[Schurkey]

To old for Obd2

??? there are plenty of scanners and APPs for laptops that work well with OBDI ECM/PCMs

Here's an example of TunerPro RT on a laptop logging a 1227747 ECM in an 88 C1500...

But good scan tools can still give you access to the datastream

There's a truly astounding number of folks who've been brainwashed by advertising for cheap-junk "Generic OBD2-only" scan tools who think that the prior years can't be connected to a scan tool, and can't have the sensors interrogated or the outputs analyzed.

94 k2500 no low end power and horrible fuel mileage - Automotive Forums .com Car Chat

94 k2500 no low end power and horrible fuel mileage C/K

www.automotiveforums.com

 

[cheetahranger]

Okay loads to unpack here, never thought I'd get so much info, so thanks everyone!
#1: Gearing. I've decided when I get the money to build the truck into a daily-able trail rig as is my plan I'm going to go with 4.56 gears. I would do 4.10 if staying with stock height, but I'll be putting a 4 inch lift and keeping the 33s, so I figure with the extra height and air resistance 4.56 would be nice. The 3.42s ******* suck right now, takes so much throttle to get going. Going to add a suburban sway bar and put in ¾ ton leafs and torsion bars as well, because I haul enough to make it worth it.
#2: ALDL Cable. I'll be purchasing one to monitor my timing/knock count and engine temp. I'll adjust the timing to what best suits my truck and also try to hunt down my idle rpm problem. Can you adjust the timing curve without a new chip?
#3: Various Improvements. I already aired up my tires to 50psi and fixed the EGR vacuum hose today, one autozone trip later. Someday in the future I'll probably put in a better cam than the piece of **** stock one. I'm gonna keep the flat tappet, as since its a newer than 93 block I don't want to go through the $ of having it converted to roller style. I'll also run direct-fit shorty headers, put in a heated O2 sensor, better flowing cat, a better y-pipe, and a mandrel bent elbow for my side exit. After all that I'll probably order a chip to take advantage of all the improvements.

 

[Nad_Yvalhosert]

There's a truly astounding number of folks who've been brainwashed by advertising for cheap-junk "Generic OBD2-only" scan tools who think that the prior years can't be connected to a scan tool

Theres also a lot of us who dont see '95 and older vehicles on a daily basis...or even monthly. And as such, have never bought archaic connectors for our expensive scanners.

Then theres the backyard mechanic who never uses a scanner.

Remember, the most expensive tool in a toolbox is the one used only once.

 

[MarkZ28]

Install a proper thermostat. Lose the bigass tires and any excess weight.

Connect a scan tool, find out what the computer is trying to tell you.
Fuel trims, knock sensor, spark advance--verify all the sensors and computer outputs. There's a reason the idle is way too high, and that's why it jerks when you put it in gear.

No functional EGR probably means the knock sensor is going nuts, and you have mega-retarded timing. Fix the EGR.

Make sure the brakes don't drag

Its a 93, it doesnt have the obd2 connector to plug into. Egr removed will not affect knock srnsors or fuel mileage, my 89 has it removed and it gets up to 22 mpg. None of the many cars that had the egr removed I had had worse fuel mileage.

 

[Supercharged111]

Its a 93, it doesnt have the obd2 connector to plug into. Egr removed will not affect knock srnsors or fuel mileage, my 89 has it removed and it gets up to 22 mpg. None of the many cars that had the egr removed I had had worse fuel mileage.

1: you can scan a 93

2: a malfunctioning EGR can induce knock.

3: I've personally not seen my fuel economy affected by EGR deletion.

 

[Schurkey]

Its a 93, it doesnt have the obd2 connector to plug into.

Of course it does not have an OBD2 connector.

There's a truly astounding number of folks who've been brainwashed by advertising for cheap-junk "Generic OBD2-only" scan tools who think that the prior years can't be connected to a scan tool, and can't have the sensors interrogated or the outputs analyzed.

94 k2500 no low end power and horrible fuel mileage - Automotive Forums .com Car Chat

94 k2500 no low end power and horrible fuel mileage C/K

www.automotiveforums.com

Get an OBD1-capable scan tool, along with the appropriate connector, and interrogate that computer. It's got a story to tell.

See my previous links (quoted above in this post) for the diagnostic info and tests available with a proper scan tool, on an '88 K1500.
[EDIT] Sometimes links don't show up in this forum due to ad-blockers. The less-fancy link is www.automotiveforums.com/vbulletin/showthread.php?t=1146067

The info I'm pointing you towards starts at Post 14, but the back-story is relevant. The photos are there and they work, if you don't see 'em it's your ad blocker or browser.[/EDIT]

GM has scan-tool compatible computers going back to 1980 1/2. That's how these vehicles were fixed when they were new.

Egr removed will not affect knock srnsors or fuel mileage, my 89 has it removed and it gets up to 22 mpg. None of the many cars that had the egr removed I had had worse fuel mileage.

EGR reduces peak combustion temperature. In the process, it's an effective anti-detonation system. Removing the EGR promotes detonation. The knock sensor is tuned to respond to detonation and then reduce timing advance.

 

[L31MaxExpress]

1: you can scan a 93

2: a malfunctioning EGR can induce knock.

3: I've personally not seen my fuel economy affected by EGR deletion.

Malfunctioning EGR can, deleted will not as long as it is deleted in the tuning. As we both know the PCM adds timing when the EGR is flowing to help compensate for the slower burn.

My MPG got better deleting EGR function.

 

[Supercharged111]

Malfunctioning EGR can, deleted will not as long as it is deleted in the tuning. As we both know the PCM adds timing when the EGR is flowing to help compensate for the slower burn.

My MPG got better deleting EGR function.

Yep, and I'm treating a physically deleted EGR with no alteration to the tune as a malfunctioning EGR.

 

[L31MaxExpress]

Yep, and I'm treating a physically deleted EGR with no alteration to the tune as a malfunctioning EGR.

The exception to that is the Vortec linear EGR. When it is unplugged with codes present, the PCM treats the EGR as disabled.

 

[Ron88]

Having read all this i would suggest finding and fixing the 1100 rpm in park or neutral issue before doing anything else.