2.8 Issues
#1
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Car: 92 Z28
Engine: Ramjet 350
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2.8 Issues
Well I haven't been able to get my 88 2.8 T5 to run how I want. It runs like crap. When cold it just hesitates real bad jerks real bad. Acceleration sucks *****. It is not smooth whatsoever. It idles high, Jerks, and seems like its not getting fuel. I have brand new fuel pump, brand new IACV, brand new MAF. Doesn't throw any codes. Occasionally it throws MAF code. I cant figure it out. I'm thinking it might have bad intake manifold gaskets. Has anybody dealt with this type of issue before? I'm ordering a cable from moates to start datalogging. But I dont know what to look for.
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Car: 1985 Firebird
Engine: 3.4 turbo
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Re: 2.8 Issues
well intake manifold gaskets are cheap and easy to replace. try that first.
Also, trim the upper to middle pieces to fit the port holes, the felpro kits fit like crap.
Also, trim the upper to middle pieces to fit the port holes, the felpro kits fit like crap.
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Re: 2.8 Issues
Replaced anything in the dizzy? Mine was acting like that till I replaced all those parts. I think the module was on the way out. And the electric grease was long gone. Also if you are getting a code for maf, it may not be good. I went through a few "new" ones, and found a rebuilt gm unit on the bay for like 30 bucks and solved everything else. I still get code every now and then, but this is because I am boosted. I should have used fatter gauge wires when I extended it.
#5
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Re: 2.8 Issues
So now on my 2.8 T5. Dam thing clicks a million times before it decides to start LOL. I'm lazy so I wanna try the same fix but a little different. I want to hook up a 12v wire from battery to button, then from button to purple wire that goes on the S terminal to save me some time. Basically the same idea. But I want to splice into the purple wire from up top . Were can I find it? I know the manual cars have a neutral safety switch but not sure were.. I also found this wire not grounded to anything. Any idea what it could be? Maybe nothing
Last edited by maroe624; 01-10-2019 at 02:16 AM.
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Car: 1985 Firebird
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Re: 2.8 Issues
I'll let someone else address your starter issues,
but if doing a swap i'd look for a 3.4 block instead of the 3.1. They'll be newer, easier to find and make more torque.
but if doing a swap i'd look for a 3.4 block instead of the 3.1. They'll be newer, easier to find and make more torque.
#7
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Re: 2.8 Issues
and i'm confused because your OP said you had all kinds of issues, but now you say it runs ok once it warms up. Did something change since the OP?
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#8
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Re: 2.8 Issues
I don't think your issue is bad gaskets. It sounds electrical to me, something that will still be there after a longblock swap, and your starter issues kind of confirm that.
Last edited by Sierra6; 01-10-2019 at 09:19 AM.
#9
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Car: 92 Z28
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Re: 2.8 Issues
Replaced anything in the dizzy? Mine was acting like that till I replaced all those parts. I think the module was on the way out. And the electric grease was long gone. Also if you are getting a code for maf, it may not be good. I went through a few "new" ones, and found a rebuilt gm unit on the bay for like 30 bucks and solved everything else. I still get code every now and then, but this is because I am boosted. I should have used fatter gauge wires when I extended it.
#10
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Car: 92 Z28
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Re: 2.8 Issues
It runs like crap when cold. When warm it runs slightly better. Worse issue is it hesitates when cold and runs sluggish when warm but doesn't hesitate much just feels like its not running like it should. Maybe its the aftermarket prom I put in there.
#13
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Car: 92 Z28
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Re: 2.8 Issues
I can"t remember the chip part number at the moment, I have to dig up an old post but it was a jet performance chip thermo master. I think i had to switch to a lower thermostat or something. One thing I did notice when setting my IACV, the step were you have to wait for it to get into closed loop. I think it has to blink slowly for it to be into closed loop . But it never got there even when warm. Just bliking fast . Maybe that is the issue now that I think of it. Ive been trting to get a stock prom on here. I"m talking to a guy he just hasn't got back at me.
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Re: 2.8 Issues
The push to start should be fused out, with a relay. Just saying.
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Re: 2.8 Issues
I have had it on there almost 2 years without a relay and no problems. If for some reason my 3.1 had trouble starting, and long crank times then definately I would wire in a relay. But it starts up in 0.4 seconds haha.
#18
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Re: 2.8 Issues
Megasquirt is a standalong fuel injection system. It would come in and replace most (or all, depending if you want to upgrade to DIS) of your old 80s tech, and any issues would be easier to diagnose then. I had all kinds of issues with mine, and even an "auto-electric" shop in town gave up on mine. I paid about $1500 for the MSII and install, but I also got a dyno tune out of it. I know that's more than the car's worth, but I was so far into my project that I HAD to get it running properly.
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Re: 2.8 Issues
But before I went that route again, I'd just do a carb swap and swap to the edelbrock carb intake. the car would breathe much better than with the crappy mpfi intake we have. But I knew I was going turbo in the future and I didn't want to go blow through carb.
#20
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Car: 92 Z28
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Axle/Gears: 3.23 Torsen
Re: 2.8 Issues
Megasquirt is a standalong fuel injection system. It would come in and replace most (or all, depending if you want to upgrade to DIS) of your old 80s tech, and any issues would be easier to diagnose then. I had all kinds of issues with mine, and even an "auto-electric" shop in town gave up on mine. I paid about $1500 for the MSII and install, but I also got a dyno tune out of it. I know that's more than the car's worth, but I was so far into my project that I HAD to get it running properly.
Last edited by maroe624; 01-18-2019 at 03:19 AM.
#21
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Car: 92 Z28
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Re: 2.8 Issues
Hey so while back I swapped out my 2.8 injectors for a set of 3.1 injectors. Recently I read that the 3.1 flow quite more then the 2.8. So I thought to myself hey maybe that's why my car hesitates real bad. So I put the 2.8s back in today and took it for a drive and it was worse then before....this time it was different though. It just completely bogs down. So I was poking around and I disconnected the MAF sensor and took it for a spin.......Runs awesome no hesitating, beautiful acceleration like never before. I'm guessing my maf is bad? But why it's brand new from autozone. What should I check. I'm gonna toss the old one back in see if it makes a difference.
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