Intermittant start problem (crank, no start) -86 tpi
Thread Starter
Junior Member
Joined: Aug 2019
Posts: 10
Likes: 0
Intermittant start problem (crank, no start) -86 tpi
Ok, here we go. '86 TPI with a 350 swap crate motor sometime in the 90s but still (seemingly) using the standard TPI setup. Spider still there on top of the engine, fuel system all looks to be the same, etc.
I'm having an intermittent start problem that seems to occur when the engine is warm but not hot or when the car has been sitting out in the hot sun. Other than that I really can't diagnose when it occurs other than to say it's intermittent.
My SES light never comes on and never has. When I plug into the ALDL diagnostic terminals, the fans come on as if the car is going into diagnostic mode but nothing lights up.
The car, when it won't start, cranks healthy but just won't fire. At those times, I hear the fuel pump relay or something under the hood "click" but the fuel pump doesn't prime. So I tested the fuel pump by putting 12V on the "G" terminal of the ALDL under the dash - fuel pump runs right away and sounds normal. However, when I do that and then try to start the car, it still won't start.
Since I purchased the car last November I have replaced the fuel filter. I also replaced the fuel pump relay - or so I thought. I replaced the middle of the three relays on the firewall, driver's side. I'm now seeing internet videos saying it's the one closest to the master cylinder. How do I tell?
When it does start and drive - I think I'm developing a click that could be a knock or could just be the exhaust rattling. It sounds like a rattle and I know the transmission mount is broke (I will be putting the new one on shortly).
What could be the issue? Why won't it start sometimes and will others?
Thanks.
I'm having an intermittent start problem that seems to occur when the engine is warm but not hot or when the car has been sitting out in the hot sun. Other than that I really can't diagnose when it occurs other than to say it's intermittent.
My SES light never comes on and never has. When I plug into the ALDL diagnostic terminals, the fans come on as if the car is going into diagnostic mode but nothing lights up.
The car, when it won't start, cranks healthy but just won't fire. At those times, I hear the fuel pump relay or something under the hood "click" but the fuel pump doesn't prime. So I tested the fuel pump by putting 12V on the "G" terminal of the ALDL under the dash - fuel pump runs right away and sounds normal. However, when I do that and then try to start the car, it still won't start.
Since I purchased the car last November I have replaced the fuel filter. I also replaced the fuel pump relay - or so I thought. I replaced the middle of the three relays on the firewall, driver's side. I'm now seeing internet videos saying it's the one closest to the master cylinder. How do I tell?
When it does start and drive - I think I'm developing a click that could be a knock or could just be the exhaust rattling. It sounds like a rattle and I know the transmission mount is broke (I will be putting the new one on shortly).
What could be the issue? Why won't it start sometimes and will others?
Thanks.
Supreme Member
Joined: Jan 2008
Posts: 1,328
Likes: 560
Car: 1986 IROC Z
Engine: 5.0 TPI
Transmission: 700R4
Axle/Gears: 3.23 Posi
Re: Intermittant start problem (crank, no start) -86 tpi
Ok, here we go. '86 TPI with a 350 swap crate motor sometime in the 90s but still (seemingly) using the standard TPI setup. Spider still there on top of the engine, fuel system all looks to be the same, etc.
I'm having an intermittent start problem that seems to occur when the engine is warm but not hot or when the car has been sitting out in the hot sun. Other than that I really can't diagnose when it occurs other than to say it's intermittent.
My SES light never comes on and never has. When I plug into the ALDL diagnostic terminals, the fans come on as if the car is going into diagnostic mode but nothing lights up.
The car, when it won't start, cranks healthy but just won't fire. At those times, I hear the fuel pump relay or something under the hood "click" but the fuel pump doesn't prime. So I tested the fuel pump by putting 12V on the "G" terminal of the ALDL under the dash - fuel pump runs right away and sounds normal. However, when I do that and then try to start the car, it still won't start.
Since I purchased the car last November I have replaced the fuel filter. I also replaced the fuel pump relay - or so I thought. I replaced the middle of the three relays on the firewall, driver's side. I'm now seeing internet videos saying it's the one closest to the master cylinder. How do I tell?
When it does start and drive - I think I'm developing a click that could be a knock or could just be the exhaust rattling. It sounds like a rattle and I know the transmission mount is broke (I will be putting the new one on shortly).
What could be the issue? Why won't it start sometimes and will others?
Thanks.
I'm having an intermittent start problem that seems to occur when the engine is warm but not hot or when the car has been sitting out in the hot sun. Other than that I really can't diagnose when it occurs other than to say it's intermittent.
My SES light never comes on and never has. When I plug into the ALDL diagnostic terminals, the fans come on as if the car is going into diagnostic mode but nothing lights up.
The car, when it won't start, cranks healthy but just won't fire. At those times, I hear the fuel pump relay or something under the hood "click" but the fuel pump doesn't prime. So I tested the fuel pump by putting 12V on the "G" terminal of the ALDL under the dash - fuel pump runs right away and sounds normal. However, when I do that and then try to start the car, it still won't start.
Since I purchased the car last November I have replaced the fuel filter. I also replaced the fuel pump relay - or so I thought. I replaced the middle of the three relays on the firewall, driver's side. I'm now seeing internet videos saying it's the one closest to the master cylinder. How do I tell?
When it does start and drive - I think I'm developing a click that could be a knock or could just be the exhaust rattling. It sounds like a rattle and I know the transmission mount is broke (I will be putting the new one on shortly).
What could be the issue? Why won't it start sometimes and will others?
Thanks.
CE light on? Even if it isn't, the ECM may be storing trouble codes. Find out by following the procedure outlined here:
https://www.freeautomechanic.com/dia...blecodes5.html
Past that, basic troubleshooting of the ignition and fuel systems will further lead you. BTW, fix first what you know to be defective; what might seem to have no connection to the posted issue could, in fact, be the cause.
Thread Starter
Junior Member
Joined: Aug 2019
Posts: 10
Likes: 0
Re: Intermittant start problem (crank, no start) -86 tpi
Ok I figured out... Prior owner of my car pulled the SES bulb (I wonder why... 
Pulled these codes:
32 EGR system
33 MAP sensor or MAF sensor depending on engine
36 MAF Burn-off circuit
Pulled these codes:
32 EGR system
33 MAP sensor or MAF sensor depending on engine
36 MAF Burn-off circuit
Thread Starter
Junior Member
Joined: Aug 2019
Posts: 10
Likes: 0
Re: Intermittant start problem (crank, no start) -86 tpi
Now it has become a constant problem. No starting at all. My positive battery terminal has been coming loose and the battery was about 7 years old, the car sat for a while, so I replaced the battery and terminals. Just like before, car still cranks, I hear the fuel pump, I smell gas after a couple tries... no start.
Thread
Thread Starter
Forum
Replies
Last Post