A few Questions

[Jbabycsx]

This is my first post so I will explain my problem and hope that someone can help!

I have a 90 GT 5-speed car that is completely stock(not even a cold air intake). The car has not been molested or hacked to pieces. I just bought it two days ago, though I did own it a few years back as well.

My problem is I notice under moderate to hard acceleration that I lose oil pressure. Under normal cruising the gauge reads around the "A" in NORMAL. When the pressure drops it falls to 0psi. Any ideas? My only thoughts were that the oil pump is going out or maybe a cam bearing?

 

[87AODGT]

i would put a mechanical gauge on it to see what's really happening, can't put too much faith in the stock sender

 

[Jbabycsx]

Thats good advice. I have an extra gauge in my shop. My car had a miss during acceleration when I bought it so I cleaned the MAF, throttle body and IAC. After doing this the car wont idle down. It stays at high RPM when you rev the engine. I bought a new IAC today and put it on, still will not idle down. Any ideas?

 

[ttopstang]

Check the linkage, could be hung up.

 

[Lawbreaker5.0]

Do a base idle reset and then check tps voltage.

 

[Jbabycsx]

Ok thanks guys I will try that stuff in the morning. I ran a diagnostic on the EEC and found a few codes so maybe that will help. It is showing the following codes.
51-Engine coolant temp sensor voltage
23-TPS voltage
54-Air charge temp sonsor voltage
85-Canister purge solonoid

 

[liljoe07]

You have 3 codes that share the same circuit. 51 23 and 54. All 3 share the same ground source.

I would clean the larger 10 PIN connectors behind the intake first. Then re-run the codes. Those codes indicate an open in the wiring or a bad connection.

 

[mob]

Like others have said, before you assume anything or do anything, put a real gauge on there to find out what it is truley at. The stock oil pressure gauge is HORRIBLE, I was having the same problem until I put an electric autometer gauge in and some how the gauge fixed my problem! But really put a real gauge on it, and if the problem persists, you may be looking at an oil pump or bearing issue.

It would suck if you put the gauge on and you are still having the problems, but it will not be a waste of money, being able to accurately read what your car is doing is priceless.

 

[kingmeirl]

i have the same problem recently with the oil pressure. stock gauge. 93 gt with a few minor mods. I noticed that between 3000 and 3250 rpms it drops to zero psi. It really worries me. Please let us know what you find out, and ill do the same. have you tried a new gauge? I was thinking today it would have to be low on oil to do this, but I have not had a chance to check it out..