1987 mustang gt exhaust cracks and no power when you first step on the gas

shadow9055 · 06-24-2009

1987 mustang gt i ran the computer test engine off and on and got codes for my tab failing and my egr replaced both and im still having the same problem. when u get on it pretty hard in any gear it bogs down real bad and cracks come out of the exhaust and then the power kicks in. i recently replaced the fuel filter cleaned the upper intake, replaced the valve cover gaskets and put a new fender mount cold air kit on it, also put a high flow cat and 2 and a half in mac exhaust on it. it seems to be a little worst since i did that. i shouldn't need a mass air flow sensor with these minor upgrades right? any ideas im fresh out....

Mustangfreak196 · 06-25-2009

You wouldnt need to convert with thoes mods. I have almost the same set up as you and i still have the old system. Have you looked at your ignition system lately? Wires, Plugs, Coil, Distributor Cap/Rotor? Im no mechanic but thats where i would start since you already replaced the fuel filter.

shadow9055 · 06-25-2009

well i just got the car 2-3 months ago and i was told all that was new so i was gonna wait a little till i put good performance **** on it. also i did check the gapping on the plugs and they were at 42........ so i set them all at 52

**EagleAutosports** · 06-25-2009

You shouldn't need to upgrade to mass air until you get performance parts like camshaft and better heads.

First, disconnect the battery and clear the codes. Reconnect the battery and drive it, to see if those codes come back. Codes don't always clear themselves out when you fix the problem.

1Slo5oh · 06-25-2009

Quote:

Originally Posted by EagleAutosports

You shouldn't need to upgrade to mass air until you get performance parts like camshaft and better heads.

First, disconnect the battery and clear the codes. Reconnect the battery and drive it, to see if those codes come back. Codes don't always clear themselves out when you fix the problem.

+1

Also, what kind of ignition system are you running?

1Slo5oh · 06-25-2009

Quote:

Originally Posted by EagleAutosports

You shouldn't need to upgrade to mass air until you get performance parts like camshaft and better heads.

First, disconnect the battery and clear the codes. Reconnect the battery and drive it, to see if those codes come back. Codes don't always clear themselves out when you fix the problem.

Just noticed you were in Graham! Pretty cool, I'm right up the road from ya. You should give me a shout if you're ever going to any car shows in the area, maybe I'll tag along in my lowly 93 LX.. We can start a MUSTANG CONVOY

shadow9055 · 06-25-2009

i actually cleared the codes already and checked them, however i don't think i ran it long enough for them to come back. Im going to go check them right now to see what it gives me now. I have a stock ignition system, it was all stock when i got it and still is except for the few mods i mentioned... how bout a vacuum leak?

shadow9055 · 06-25-2009

haha, ok so i just ran the engine off test and i only got one code. its a new one this time "67" which lists like 5 different things "improper signals received from ; NDS neutral drive switch, NGS neutral gear switch, NPS neutral pressure switch, CS clutch switch, MLP manuel lever position, or ACC air conditioner clutch...
None of that means anything to me, any ideas?

shadow9055 · 06-25-2009

so i did the engine running test now and i got the same codes as before. 44 and 33. 44 is thermactor air system failure and 33 is egr sensor indicates valve is not opening. Since i just replaced the egr valve im now thinking its the egr sensor or solenoid. im thinking sensor, anyone have any ideas? Also, the thermactor thing has me confused since the engine off test said the solenoid was bad so i put new ones in. Although im still getting a failure while the engine is running with the key off test i don't get the bad solenoid code..... so confused

ttopstang · 06-25-2009

have you checked the timing?

shadow9055 · 06-25-2009

no, i just got the gun today from a guy i work with. however im not really sure how to do it. so thats what im searcing for online, how to check the timing. As a side note, it idles perfectly and after i drive it for a 10 mins or so it runs great.......

bookel · 06-25-2009

Mine wouldn't fire when it would get hot (running temperature). It would run fine then I turn it off and wouldn't fire a lick until about 0 minutes later and it was cool. I replaced the TFI module (no results). Today I put in a new distributor, cap, rotor button, plugs (gapped 0.05), plug wires and ignition coil. I set the timing to 14 degrees (running 93 octane fuel). It seem to firing up fine at operating temp now however I now have the same symptoms you describe. It cracks and backfires and has no power when I get into the accelerator hard. I'm not sure what is up with that. Mine's an 87 with auto trans. All stock.

shadow9055 · 06-25-2009

does yours clear up after awhile or does it run like that all the time?

bookel · 06-26-2009

I just did the tune up today so I haven't had a chance to give it a real run. I'm taking a trip on it tomorrow. It'll be about 100 miles each way. I can post tomorrow night and let you know. I've read the timing on my car should be about 12-14 btc. I'm not sure if that's right or not or if being an automatic it should be different.

shadow9055 · 06-26-2009

Im not positive but i think ur stock timing is 10. Ive read that it should only be turned up 2 or 3 degrees, and if you go more then that you will it start pinging. If you go over 3 degrees you should be running a higher octane fuel to make up for it. However you said you are running 93 so you should be golden. I don't think its anything different if you have an automatic.