I NEED HELP!!!!!!!!!!!

[Guest]

Ok , lets start with saying I am new to the site. I have a 1988 gt 5.0 vert. For some reason I can not get this thing to run right. It is speed density, stock heads, E303 cam, 1 5/8 headers, 2 1/2" exhaust w/ flowmasters. I am getting a popping noise out of the intake at acceleration when cold, as well as idle surges. Took it to a shop and they told me I needed head gaskets. Changed them and no diff. any help is appreciated.

[BraMas]

What is your timing set at? Also sounds like you might have a intake leak/vacuum leak?

[Guest]

I did read last night that it needs to be at 10°, and I believe that we set it at 0. gonna play with that today and see what we come up with. Also I read some where that changing to the E303 cam may cause lower vacuum? If so, is there any way to establish stronger vacuum?

[Guest]

.....

[phrostygurl]

I have an 03 and i am having the same issue you are, kinda wierd... but i have to get the intake replaced and a new vacuum line and a new cam sensor. I think we are having a tech day coming up soon .

[loosenut41983]

I did read last night that it needs to be at 10°, and I believe that we set it at 0. gonna play with that today and see what we come up with. Also I read some where that changing to the E303 cam may cause lower vacuum? If so, is there any way to establish stronger vacuum?

there isnt any way to create more vacuum than the engine is putting out. one idea is to idle a little higher. what is your idle set at? also, are you getting any missfires? i know this is hard to determine on an 88, but you should be able to tell.

[Guest]

it doesnt seem to be misfiring, but I wouldn't rule it out either. what could cause a misfire other than the obvious( i have new coil, plugs and wire all are accel)

[loosenut41983]

there could be a couple if things. an injector failing, intake gasket leak, cylinder problems like rings, valves or head gasket. also you may just have some parts that dont match up timing wise. like an overlapping cam lobe

[Guest]

i have a E303 cam, and had stock heads redone with springs matched for that cam, I thought that the cam could be the issue but problem was there before switch. is there a way to tell if injector is failing.

[loosenut41983]

an easy way is to unplug one injector at a time. but the way i would go is to hook your engine up to a scanner, cut off one injector, and see if the problem still continues with each injector

[Guest]

jumped my timing to about 14-16 °. runs way better still seems to mis ? i guess, did try to unplug injectors, the ones able to be reached did not seem to make a difference when not hooked up? :*bonk(: Trying to get it smoothed out before 28th street.................

[Guest]

also is idling at 1500rpm to high?

[Danstang]

Yeah, just a bit. You should be 600-700 or so. I'm thinking TPS sensor needs the base idle reset. This seems to be a common issue in 86-93 'stangs.

Here is a link to something that may help you------> Mustang idle surge and base idle reset

[Guest]

tried the base idle reset. tps voltage was at .67 (in the holes pre drilled on tps) elongated the holes got .96 - .97. seemed to work great untill i plugged IAB back in, running about 1200 rpm now. also there alot of moisture out of the exhaust. Running RICH. First i thought head gasket, but no antifreeze smell.

[Guest]

pulled codes with key off got 31 54 63. idle just wont come down

[Danstang]

pulled codes with key off got 31 54 63. idle just wont come down

Have you found out what the codes are?

[Guest]

54 says iat too hot or out of range
31 egr ? Low voltage?
63 evp,low voltage

[Guest]

63 Throttle Position Sensor (TPS) signal too low TPS
54 Intake Air Temperature (IAT) or Vane Air Temperature (VAT) signal high - IAT VAT
31
(O,R,M)
EVP - EVP signal is/was out of range - EVP


(O,R,M)
EVR - EVP signal is/was low - EVR


(O,R,M)
PFE - PFE signal is/was low - PFE

but what does this mean..... also It would not let me run the key on engine on test code 98 kept coming on.... did not pass key on engine off test.........?????????? Can't wait for Friday....hopefully the car is running better by then.

[loosenut41983]

the moisture could just be condensation from starting and stopping your stang constantly. i can pull those codes up on identifix tomorrow and find out what they are. ill let you know what they come up as.

[loosenut41983]

ok... first off for code 63. replace the throttle position sensor. dont elongate the holes before you install it. this should fix the high idle.

code 54 is for the iat sensor. look at the connector on the sensor and make sure the terminal ends are ok. if not, replace both connector and sensor. if ok, just replace sensor.

code 31 is for the egr valve and evp sensor. there are apparently two different evp sensors on the egr valve. and both have different voltage specifications. but im pretty sure a new egr valve should have the correct sensor on it.

also, there is a 10 way connector on top rear of the intake manifoldnear the egr valve that could be loose or have a bad connection. this will cause a high idle and codes 31, 32. if loose, tighten them down with two tie straps.

i know this sounds like a lot. but i would check the 10 way connector first. if that doesnt help, then replace those sensors

[Guest]

ok changed all of the sensors mentioned. will check the connections. did not change actual egr but did change the sensor part. also did try to tighten the "salt and pepper shaker " 10 pin connectors, although I do have low vacuum, i cannot seem to find any leaks. Hopefully I will get to meet some of you at the metro cruise this weekend. and you will be able to see the ride......

[Danstang]

....and still no luck, huh? Not sure what to think of the low vacuum. How's it running now? Still missing and high idle? We'll all be at the Grand Rapids Brewing Co., I'm sure you'll see us.

[loosenut41983]

do you still have a high idle??

[Guest]

Yeah still high idle. Not really missing, I have noticed lower idle at lower temp. Maybe clutch is bad in fan? Not cooling enough? Not running real hot but is about to the O in normal.

[Danstang]

Your temp looks good from your description. Just need to figure out the idle. Anyone else out there got any ideas?

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