95 firebird bogs down when it gets warm

[nascar24aa]

HELP!! I have a 95 Firebird been working on. Just had the top end rebuilt. EGR valve replaced,plugs and wires,oil pressure sensor . Cut off the Cat because it glowed and started the inside of the car on fire. It was bogging down prior to cutting the cat. There is no check engine light so no codes. Smells like it is running rich. Check fuel pressure and it looks good.Throttle Position sensor is good.Next is to check the MAP which is a bear to get to. Any one have any suggestions??

[Markgc]

Have you run a compression test on it - sticking or open exhaust valve might heat up your cat a bit.


Mark

[Markgc]

Is the ignition timing good?

I bought a scan tool - it is a joy to be able to read sensor readings from the screen. You would be able to read the MAP sensor output without getting you hands dirty - just a suggestion

[nascar24aa]

are you referring to the scan tool for the OBD I/ OBD II??? I don't have a check engine light so that won't work if that is what you are referring too.

[Markgc]

The beauty of a scan tool is that apart from reading error codes it can read some of the actual data coming off the on-board computer. I am doing this with my 89 Blazer which doesn't have a working check engine light. I can read the voltage coming off the TPS and watch it change as I press on the accelerator pedal. I can also read the voltage coming off the MAP sensor. These are just a few off the sensors that I can access. Your OBD II system will have more data availble than I have on my older OBD I system. With a scan tool you would be able to see what your MAP sensor is telling the ECM


Mark

[OverBoardProject]

Welcome to Automotive Forums nascar24aa

This is the Blazer board, but we'll help you out as much as possible.

The firebird board is located here
http://www.automotiveforums.com/vbul...play.php?f=384
and the comaro board is located here
http://www.automotiveforums.com/vbul...splay.php?f=11

To me it sounds like a timing problem.

I don't know about with your car, but some Blazers require some wire disconected to set the timing properly. My guess is that this is where your problem is.

Someone here will probably know more about it than I do

Good Luck

[Im3good4u]

hey man i was having similar problems and after i changed the EGR, and IAC it got better but i had to take it to Pep Boys an although i had no light on they said they found some vaccums leaks and it fixed the problem.....Good Luck

[nascar24aa]

compression test was good. Gonna hook it up to the scanner and see what I can find. This goofy car has an OBD I computer with and OBD II hook up to the computer so you have to take it someplace of pay $300 for the whole kit and kaboodle. Thanks for your help mark

[Markgc]

I got a really good deal on my OBD I tool but the OBD II tools are much more expensive. I would do a little research on the web first. You might find a better deal out there than shopping locally.

Another trick is to attach some wire to a sewing needle - you can use heatshrink tubing to hold the wire in contact with the needle. You can use the needle to probe wires by pushing the needle through the insulation and into the copper wire. When you remove the needle the small hole in the insulation will close back up.

[nascar24aa]

thank you all for your help. It ended up being the MAP. Now I can get the exhaust put back on and we will be back in business.

[Hairytoad]

Originally Posted by nascar24aa

thank you all for your help. It ended up being the MAP. Now I can get the exhaust put back on and we will be back in business.

Was this hard to replace? Would i be able to do this by myself, im having the same problems with my car. Also, is there a good site to show this step by step? Thanks.

[nascar24aa]

You can get it in the Haynes manual. It will be either in the electrical or emission section of the book. It took about 5 minutes to change.