Hello I'm New to the forum, I have a 93 EB bronco w/ a 5.8 right when I accelerate the engine seems to hesitate then recovers quickly. This only happens right when I first hit the gas. The truck runs very strong even with 109k on it

 

Clogged cats? Have a muffler place check them. Also when was the last time you did the spark plug, air cleaner, oil, cap and rotor on it. It all contributes!

 

do you know if many shops perform the test for free?? becuase i would like to get mine tested as well?

 

Some will, some charge. I have a shop here in cali that does not charge. It take them like 2 mintues to do the test. Most should not charge. but who knows.

 

really?!, thats good that some don't charge. I think that I'll go have my cats looked at

 

Thank you all very much, My exhaust system is falling off as we speak so I won't be long before the problem is fixed

 

You may also get the codes read.....a hesitation before take off during acceleration can be a dirty of faulty EGR valve....

Clogged cats will render your engine powerless across all rpm ranges....

regards

 

oh wow, it can be the EGR?? i thought it only came on in higher rpms? my truck is doing the same things, when it is cold it starts but will not keep itself alive without my foot on the gas, and then it acts just slightly retarded at starting out but will feel a huge power jump once it gets to mid range. i know it has nothin to do with the exhaust becasue it was all replaced recently.

 

Like it was metioned, you may want to pull the codes, could be EGR, IAC, TPS. just some more stuff to check. good luck! DW

 

A car expert that I listen to on the radio gave me this technique for checking your exhaust restriction. All that you need is a vacuum gauge. I used the one on my might mite self bleeding brake tool that uses vacuum to bleed the brakes. Hook the vacuum gauge up to a manifold vacuum source when the engine is warm and check your vacuum reading at idle. Then hold the accelerator at 2500 rpms until the engine vacuum steadies. You should see an increase by at leasts a couple of points at the 2500 rpm range. I saw an increase from 20 hg" to 25 hg" with my 1990 351W. If the reading stays the same or drops, then there is a restriction.

 

I've allready replaced the EGR valve and my truck seems to be getting worse. In real Hot weather with the A/C on the truck bogs down thru all rpm ranges. and sometimes makes a chuging or coughing sound

 

In real Hot weather with the A/C on the truck bogs down thru all rpm ranges. and sometimes makes a chuging or coughing sound
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at night in full darkness, pop the hood and look for arcing spark plug cables
specifically on the EGR stovepipe that comes from the exh manifold...cables lean up against it and I had three cables cross firing....talk about a light show!!!

Take the TB assy off and clean the front and backside of the assy OFF the intake....I used a razor blade and a little bit of gojo hand cleaner....then
wiped it off with a clean rag wet with a little carb cleaner...

you will need a new TB to intake gasket

My truck had the surging idle, stalling and hesitation and I just went ahead and replaced the O2 sensor, Egr and all selenoids),TPS, air bypass valve, PCV, air temp inlet sensor(on top of lower intake), when fired up the truck ran silky smooth.

Lots of people argue to pull the codes, but I didn't want to muck with things for a while....a long while so I swapped alot of the stuff out anyway.

Also get your timing checked and get your fuel pump pressure, also running the AC will drain some power because it takes some hp to run the compressor.....

If the miles are high I would also perform a compression check to make sure all cylinders are within 5 lbs of eachother (or close to it)

Also check intake, and vac lines for leaks using a propane bottle and a small hose....at idle...if the engine speeds up, then you have aleak in that area...if no change in idle, then seals are good.

Then pull the spark plugs and check for fouling (some do go bad even though new) look for an offwhite to brownish ashy deposit....

If black ash, running too rich and O2 sensor may not be running properly...
If white and glazed, to lean and you may have a vacuum leak... (both of these can also be the fuel PSI reg)

Pull the codes man!!!it is a good place to start.

 

Anyone mention the fuel filter?