Engine 1987 GT wont rev past 2000 rpm? Help?!

vBlox

New Member
Jul 26, 2022
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Okay so I bought this car a little over a week ago not running and the owner said it needed a new fuel pump. Bought a new fuel pump slapped it in and bam it fired right up, killed the engine went to check oil, coolant, etc and when i went to fire it back up crank but no start. I replaced the spark plugs, coil, distributor cap & rotor, tfi module, fuel pump relay, tried another known working distributor, starter solenoid, and the pcm relay. The pcm relay was corroded really badly and when i slapped the new one in it started up. Now the problem I’m having is the engine is idling at 1k and will not rev past 2000 no matter how slow or fast i press the gas pedal. Timing does not seem to be the issue as I’m at TDC on the compression stroke and retarding/ advancing the timing does not change how the car idles it still wont rev past 2000. I also tried to pull codes using an OBD1 Scanner and the wire jumper method neither worked. Any ideas? Will upload a video to youtube and post the link here in a bit.
 
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General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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#1 that engine is not hitting on all cylinders or the firing order is not correct
#2 if you can't pull codes from the computer it's likely the computer has problems.
What else do you know about this car?
 

rednotch

Founding Member
Aug 14, 2000
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If you can't pull code first thing I would check after the normal stuff like fuel pressure, timing compression etc would be the signal voltage on the sensors... Easy to check the tps Or mass air to see if its there is an issue, if its way out of range crack open the ecu and look for burnt traces on the back side of the board, then go over the mass air swap they did on it chance are that's what killed it... Lots of info on the site how to check it if you search. Rebuilds run about 120 ish from ecu exchange , vs people asking stupid money for 30yr old ecus. I don't know how long it sat or how nasty the tank was but for the $100 a replacement tank costs I just replace them, seen too many that sat to long get a new pump only for the rotted tank to kill it shortly after
 

Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
39,477
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It's misfiring badly which is why it won't rev.

I'd probably go ahead and change the fuel filter. You'll have to go to basics and check things like the firing order, the timing, the fuel pressure.

I'd keep working on pulling those codes. 1987's don't have a functional check engine light, so someone wired that light up. Who knows if it was done correctly. I see a mass air swap, so i would double check if that wiring is correct and what ECU number you are using.

Are you trying to get the CEL to blink? I would use the below scanner and pull the actual number codes.

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View: https://www.amazon.com/INNOVA-3145-Ford-Digital-Reader/dp/B000EW0KHW/ref=asc_df_B000EW0KHW?tag=bingshoppinga-20&linkCode=df0&hvadid=80195681205772&hvnetw=o&hvqmt=e&hvbmt=be&hvdev=c&hvlocint=&hvlocphy=&hvtargid=pla-4583795269552441&psc=1
 
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