89 454 tbi wont run right

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ajd89

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Ok guys just picked up a 89 crew cab 454 tbi in it. Been sitting a few years got it home and got a battery in it and it started up. But didnt want to stay running and had the keep foot on the gas. Pulled the plugs and they were pretty bad so I replace them and the cap and rotor. Wires looked good. Found one boot was off and Laying on the frame plugged that one back in! Still running about the same now. Spitting and spudding wont rev above 2k. So I did some looking around and came up with the coolent temp sensor maybe a weak fuel pump. Maybe timing but the distributor is tight and I dont think it's that. When cranking it seems like it is dumping the fuel in not the fine mist as is talked about in other posts looked at my 87 tbi truck just to verify and this truck you can hardly see the gas going in at idle. So question is would I weak pump do that or is it the cts telling ecm to pump to much gas? Pulled the tbi apart last night make sure injectors wernt plugged seems ok going to clean and reassemble. Truck has all the egr crap a mild cam and headers if that makes a difference.
 

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Ok guys just picked up a 89 crew cab 454 tbi in it. Been sitting a few years got it home and got a battery in it and it started up. But didnt want to stay running and had the keep foot on the gas. Pulled the plugs and they were pretty bad so I replace them and the cap and rotor. Wires looked good. Found one boot was off and Laying on the frame plugged that one back in! Still running about the same now. Spitting and spudding wont rev above 2k. So I did some looking around and came up with the coolent temp sensor maybe a weak fuel pump. Maybe timing but the distributor is tight and I dont think it's that. When cranking it seems like it is dumping the fuel in not the fine mist as is talked about in other posts looked at my 87 tbi truck just to verify and this truck you can hardly see the gas going in at idle. So question is would I weak pump do that or is it the cts telling ecm to pump to much gas? Pulled the tbi apart last night make sure injectors wernt plugged seems ok going to clean and reassemble. Truck has all the egr crap a mild cam and headers if that makes a difference.

Replacing the CTS is always a must. Those things just wear out over time. You replaced the plugs and inspected the wires, but I would get a new cap and rotor and call it good on the ignition system for now. Also, check for vacuum leaks. Several smaller ones or one or two big ones really hurt. You can inspected the lines, boots, and connections and do the spraying of the aerosol combustible around key areas. Be mindful of the base gasket area and the EGR valve. The EGR valve can loose its ability to hold vacuum, or it'll stick open. You can test it by working the plunger to make sure it's not stuck, and you can also push the plunger up, cap your finger over the vacuum port, and let go to see if it stays up. If it falls down, it's no good. If you can't get it to stay running long enough to check for vacuum leaks, you can either wait until you make headway with the other issue or use smoke from a cigarette, cigar, or e-cig and blow it in backwards from the vacuum connections at the TBI to see if it wafts out from anywhere. I'm not encouraging you to smoke if you don't, but if you do, that's an option. Now the fuel issue. You absolutely have to check your pressure. You want to see thirteen pounds. If not, the pump's bad. Also change your fuel filter when you remove it to do the pressure test. If the filter and fuel pump tests have happened and still no fix, I'd rebuild the TBI (super easy). That'll ensure you have new, clean gaskets/seals, screens, and a new FPR diaphragm. All of this should work, and the only thing really left after that is a stuck open injector, but I suggest working your way up to that because there are a couple solutions, and that's the last thing you really ought to look at. I meant to ask you. What are you getting for trouble codes? Is your computer showing you an SES light at startup? You know to jump the A and B pins on the ALDL connector with the paper clip and count the flashes to collect the codes, yes? You should get three twelves, up to three different codes that are flashed three times, and a concluding set of three twelves. If nothing's happening when you try to interface with the ECM, the bulb for the light in the cluster is burnt, or if you're just getting a solid, unchanging light when you jump the pins, the ECM is bad. Sensors to really be mindful of while getting started with this project (already mentioned the EGR valve and the CTS) are the IACV, TPS, and MAP sensor. You should get codes if there's something wrong with any of them, though, especially if you can get it running long enough.
 

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Just to be sure you covered the basics, I didn't see anywhere in your post that you got rid of the old gas and put in fresh fuel.
 

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Fuel filter.

Check for codes.

My next thought involved questioning the FIRING ORDER.
1-8-4-3-6-5-7-2 around the cap.
Then I'm at module without improvement.
Report results here.
 

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Thanks for the suggestions guys! I did change the cap and rotor forgot to say that. Old one didn't look to bad but can't hurt right? One tank didn't have much gas in it so i put a couple gallons on fresh gas in it with some Lucas in there too. And the firing order I double and tripled checked I was hoping it that was all it was lol. So plan now since I have the tbi off i will rebuild it. New cts and fuel filter. And will check the fuel pressure at the same time. And egr along with vacuum leaks! As for the ses it dont light up not sure why i guess something i should look at and pull the codes off. It should light up soild when the key is on right? Maybe bad bulb? Once again thank you for the help. Going to try to work on it this weekend and I will let you know!
 

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Yes, the SES should illuminate for a couple seconds for bulb check when the key is cycled to the on position.
 

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Yeah, see if the bulb is bad. Also check your two ECM fuses. If all that looks good, then the diagnostic circuit in your ECM burned up in addition to likely other things needed to make it run right.
 

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If it is bad im guessing the answer is no but can I swap one from a 87 5.7 parts truck? Maybe I can swap the chips too? Idk
 

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If it is bad im guessing the answer is no but can I swap one from a 87 5.7 parts truck? Maybe I can swap the chips too? Idk

Yes, you can. Both use the 1227747 ECM. As you said, you need to swap the PROM chips.
 

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2 other questions on the passenger head there is a sensor like the one that runs the temp gauge on the drivers side whats the other one for just one wire might be green that goes to it. It was unhooked so just wondering. And how come it has a adapter I guess not sure what to call it under the tbi (not a spacer for more air it has that also) with coolent lines goes to it. Dont you want colder air in your engine more dence and hold more gas right? Almost looking like you could take that off and bolt a carb to it. Dont know much about these bbc always had small blocks.
 

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Guess I should have done some googling before I asked those questions. Answers were pretty easy to find sorry. The wire is for the electric fan in front of radatior. And the adapter with the coolent pass though can be removed but it was to prevent ice up in the throttle body when it's cold! Got my fuel filter and coolent sensor today had to order the tbi rebuild kit it will be in tomorrow
 

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Guess I should have done some googling before I asked those questions. Answers were pretty easy to find sorry. The wire is for the electric fan in front of radatior. And the adapter with the coolent pass though can be removed but it was to prevent ice up in the throttle body when it's cold! Got my fuel filter and coolent sensor today had to order the tbi rebuild kit it will be in tomorrow

Did you check that bulb and those two fuses to see what your ECM situation is?
 

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Yeah... Hard stop at the SES light.
No further progress is possible. Go ahead with the little monies you got there, but we have to fix the light? and pull codes... That's actually the starting place for your '87.
 

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Ok so you guys will love this finally got time to work on the truck this weekend i did check the ecm fuses both were good. Didn't get to the ses bulb yet though. Egr valve was good. Vacuum line were ok but wouldn't hurt to replace some of them. I put new fuel filter on and all new gaskets on the tbi and new cts. Pulled the plugs they were dirty already so cleaned them again. And checked compression got 140 150 in all but 1 2 and 7 couldnt get the same reading twice as low as 25 and up to 150. Figured valves or rings. So i Got it running better with the clean plugs and started hearing a ta-ting from the front of engine was looking thinking fan hitting shroud but couldnt see where so pulled plug wires and 1 and 2 didn't make any difference but when i pulled 2 the noise went away...so I pulled both valve covers 2 had a bent rod and 1 and 7 were missing push rods. Great! All on the intake valves. Not sure how tight the rockers should be but they were just more then finger tight. One of the owners who I went and talked to put roller rockers in it and a cam. Idk if that has something to do with it or not? I'm getting a lot of different answers on why and where the other push rods are so i guess i need to do some looking online see what I find. Maybe some one here will have some helpful thoughts also.
 

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Wut.

Huh.

If you're missing PUSHRODS , it's because somebody chose to remove them.
That is a VERY short list of suspects!

You are better off trusting the strangers on the internet you crossed paths with in the GMSB forum.
 

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