1987 chevy truck wont start

[heehawracing]

i have a 1987 chevy truck 350 throttle body all orginal it will not crank it will fire.. but the injectors will not work i have power on the hot side but it has no ground and i have changed the module thanks to any one with any info

[Eyegore]

Need further explanation, it will not crank it will fire? If its not cranking then check battery, starter, cables to start with

[heehawracing]

it turns over the spark plugs fire but no ground to the injectors
thanks

[Goldfinger]

Fuel,air, ignition. If you are getting power and air but it won't crank check the fuel etc. just trace it throughout the system ruling out possibilities

[heehawracing]

for the fuel injectors to work there is a positive and a ground it works off the ground the positive stays hot it is not getting a ground i am trying to find what to test next and how to test it the most common cause of this problem is the module i have replaced that so i dont know what to test next
thanks

[lindstromjd]

Buddy of mine has a 90 Camaro with TBI that did almost the same thing. He could get it to fire up, but not stay running without gunning it the entire time. Turned out when we took his dash apart, we forgot to plug his anti-theft module back in. Does your truck have an anti theft in it?

[sandorjoben]

How long have you had the truck? I had the same problem when I got mine and found out a mystery unmarked switch I'd thrown in the truck a couple days after I bought it cut the power to the injector pod as an anti-theft feature added by a previous owner.

[rwhit57]

There is a pickup coil in the distributor, sounds possible, but too little info to be sure.

[heehawracing]

it could be the pick up coil but im not sure if that would keep the injectors from working i think i have an extra distrubuter i will try it tomorrow because that will not cost anything

[Hoods69BadBowTie]

Have you made sure your fuel pump is working correctly yet? If your getting spark the pickup coil should be good.

[heehawracing]

fuel pump is fine

[rfmaster]

Make sure that SES light goes from solid on - blink off - solid on as you move ignition key into run position ( before cranking). If SES does not come on check EFI fuse - very common problem. If ECM does not have +12 during cranking it will never fire injectors.

//RF

[skeebo23]

same issue with mine last week, we replaced ignition module and map sensor and that fixed the problem

[lurch115]

if the ignition module or pickup coil is bad the injectors will not work. if i remember correctly you can follow the wiring for the injectors and they plug directly into the ignition module.


sorry, i was thinking backwards. the coil plugs directly into the ignition module, not the injectors

[skeebo23]

the ignition module is located right under the distributor cap, remove cap (2 screws), and the module is along the backside held on by two bolts and 3 connections. very simple, just a little stretching to reach. Part is around $25.00

[jchav62]

Originally Posted by rfmaster

Make sure that SES light goes from solid on - blink off - solid on as you move ignition key into run position ( before cranking). If SES does not come on check EFI fuse - very common problem. If ECM does not have +12 during cranking it will never fire injectors.

//RF

I agree with this 100%. I had the same problem some years back in a Nevada D.O.T. survey rig ('90 GMC TBI 350).

[Don SC]

Actually, heehawracing, you should be seeing if the truck is throwing any codes so you can troubleshoot it more properly. Do you have an OBD1 code reader?
http://www.amazon.com/Equus-3123-GM-...9305208&sr=8-9

[rfmaster]

Originally Posted by Don SC

Actually, heehawracing, you should be seeing if the truck is throwing any codes so you can troubleshoot it more properly. Do you have an OBD1 code reader?
http://www.amazon.com/Equus-3123-GM-...9305208&sr=8-9

You do not need code reader - codes can be pulled by shorting pins A&B of ALDL connector. This will put ECM into diagnostic mode and if there are stored DTC's ECM will cause SES light to blink stored DTC code number.

//RF

[Tonio327]

Ok reading this and I have a 87 that's not starting but the injectors are working what can I rule out if the injectors are fine could it still be the ignition module r anything like that
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[Don SC]

You guys can throw parts at your trucks all day long and still not fix it. Why not just read what rfmaster and I are suggesting for you to do? Either a code reader for @ $25 or a FREE paper clip jumper at the ALDL connector under the dash -left hand side- .Jumper pin A to B with ignition on and watch the "check engine" light. It gives a flash, followed by 2 more flashes. That is a code 12. It tells you that the ecm is ok. Then if any other codes are stored in the ecm, they will flash also. Each code flashes 3 times. Write the code down and do a search on your computer at the following site.
http://www.extreme-check-engine-ligh...%20Decoder.htm

At least this way you'll be headed in the right direction for a fix.
On edit, remember, when you disconnect the battery you wipe out any codes that are store in the ecm.

[Tonio327]

Will try this out I just got this one after my 82 was stolen it has the original motor but the dash has some issues will c if the egine light even lights up first I'm at square one again almost feel like saving for a crate and start from there hate learning everyone else rigged up stuff with a blind eye truck was starting find when I got it now I'm home and nothing
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[Tonio327]

Odd thing I just went to try the hold the gas padle down and start it and it turned over I turned it off and tried it again and nothing the injectors are working but I'm thinking it's still the throttle body
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[heehawracing]

I tried to check codes but could not get any anyway I put a new distributor in it and that fixed it
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