Really in need of some advice

[Shane S.]

Ok I have a 98 svt & its had an issue between 1000-2000 rpms ever since ive had it. Its had a stumble & popping when decelerating but its gotten worse in the past couple of days. Last night it was really jerky when accelerating or decelerating between 1000-2000 & when decelerating it would pop out the exhaust a couple of times.The idle doesnt seem as smooth as it should be either. I studied the rpm range & if I held the throttle at 1500 rpms the engine would stumble right there & cough a bit but only right there. Thats where the jerking is when driving too. In the higher RPM range when driving its fine till you drop below 2500 ish those issues come up. I have replaced alot of parts since Ive bought the car, new fuel pump (whole spectra assembly from autozone) Ford TPS & ford IAC from rock auto, cleaned the MAF with the special cleaner, new PCV valve & tube, IMRC bushing replaced & working, Autolite app104 spark plugs gaped at the .54 the manual says, new duralast spark plug wires, new vacuum line from valve cover to intake, new O rings on the intake manifold vacuum lines & probably a few things im forgetting. 

Now some concerns, turns out autozone doesnt carry anything for the svt so the plug wires & fuel pump they gave me were for the SE v6 not the SVT model, is there any difference between those SE & SVT parts? Maybe the spectra brand wasnt a good choice but at the time its all I could afford cause the car decided to die right before christmas. Also maybe the duralast wires werent the best choice either. Another concern is when I was installing the new plugs I noticed the previous owner didnt hook up the ground strap to the coil pack & by the looks of the worn old plugs it had been disconnected for a while. Maybe that messed up the coil pack & is causing my issues? Also I noticed a post by Terry here that suggests the spark plug gap should be at .39 instead of the .54 to help solve misfires? I might give that a try. I dont have a CEL & I hooked up my code reader & had no stored or pending codes. I had the 420 code a while back but I cleared it after I got my new mufflers installed & its been a couple of months & it hasnt come back on. I have yet to replace the upper & lower intake gaskets but I sprayed starter fluid around it & no idle change. Still need to replace the O2 sensors but if one was bad Id have a CEL right? Any help on this subject would be greatly appreciated cause im at my wits end throwing money into this car. My Triumph spitfire is running better & costing me alot less money to maintain! I'll post more details if I think of anything else.

Thanks guys  

[Terry Haines]

...have you pulled any codes or checked EEC for pending codes?..

[Shane S.]

Yes there aren't any codes at all. I wish it were so I could pinpoint this. I'm thinking of making a smoke tester to make sure I didn't miss any rotten vacuum lines cause this car had a lot. Where do the lines on that egr sensor go? I was doing a check on my break at work and I can hear a hiss around that area somewhere so its probably more vacuum leaks but what are some other things to check?

[Shane S.]

well went down & sprayed all over the intake again & all over the place looking for vacuum leaks & no rpm change at all. I did notice that the upper intake manifold around the gasket has some brown residue around it. I sprayed it to see if it was leaking and nothing but im guessing that residue around the upper intake gasket points to a leak so Im going to replace it & see what happens. 

[Terry Haines]

...the 2 small tubes on the main egr tube go to the DPFE sensor..Be sure they are ok and in good condition. Brown marks round intake gasket etc sounds like gum/ PCV stain..If can be seen on the outside of the joint then chances are you have some bad gaskets..

[Shane S.]

Thanks terry, I inspected those EGR tubes & they're one of the only rubber hoses on this car still looking decent. I'll go ahead & order the intake gaskets then cause on the passengers side of the engine where the upper meets the lower its pretty stained brown. Advanced auto has the felpro ones now in stock but cant do anything else today cause its raining now.

[Shane S.]

How do you check the coil? I want to do a test on it before I spend more money on intake gaskets cause of that ground strap being unhooked.

[Shane S.]

Changed plug gap to .039 and nothing. Plugs and wires look good and normal

[Shane S.]

well I removed the upper intake, not to bad of a job. Every thing is filthy & some passages where the throttle body bolts up are blocked with crud. How do you clean the throttle plate? The back is coated with crud & there is a sticker on it that says do not clean cause of a special coating. The gaskets look like they've been leaking so this will hopefully fix my issues. Still have to remove the lower intake but it got dark out.

[Terry Haines]

...I would also look at the throttle plates on the lower intake manifold and do upper & lower at the same time. For the t/body I have found that Mac's carb, choke a throttle cleaner the best ,from napa I think or a throttle cleaner by crc.. For the manifolds  start of with acetone and a wooden handle wire brush..do this outside and in a large metal tray..acetone eats paint/plastic etc so take care with your hands and eyes..once you have the worst off a final finish clean with the mac's cleaner and it should be fine.

This will take some time ok...

[Shane S.]

Yea I figured it would take some time, the lower intake is just as filthy. I'm going to remove it too of course, it just got too dark out last night. I got the bolts loose, I just have to undo the fuel line and imrc linkage and it'll come out. Thanks for the info, I'll take some pics before I start cleaning and post them.

[Shane S.]

Lower intake is off, going to remove the injectors & rail before I start cleaning so I dont run the risk of damaging them. I just ordered the parts & made sure to order new O rings for them. Any tips or anything in particular I should  know about removal & installation of the injectors besides greasing the O rings?

[00CSVT150]

Just be careful removing them so you don't break the tips or anything. I've never had a problem on a Contour but have on other vehicles. Just take your time and make sure everything is good and clean. You may want to consider replacing plugs, wires, PCV valve and possibly valve cover gaskets while you have it all torn apart.

[Shane S.]

It came out fairly easy. I got the lower intake clean but that took a whole afternoon so I'll do the upper tomorrow. There was a thick buildup of crap in there and a thick layer of black on the back of the throttle body. This car should run so much better. What's safe to clean the fuel injectors with? They got a little dirty and I just want to make sure they're really clean before I install them. I was thinking just gas and a rag. I already replaced all that stuff csvt150 Before i removed the intake a month ago lol its funny.

Edited April 22, 2014 by Shane S.

[00CSVT150]

I've sprayed them down with carb cleaner before and never had an issue with it. Gas should work as well.

[Shane S.]

Ok thanks! I'll just wipe them down good with gas, they just got a little dirt on the outside. I was thinking of using a pressure washer to blast the inside of the upper intake clean since you cant clean the inside really good. Whats the intake made of? If I get the inside wet is there a chance it might rust or trap water somewhere? I just thought it would really get the inside clean.

[Terry Haines]

Standard upper and lower intakes are ally so once off the engine you can clean them well.Pay attention to the secondary butterflies ,they gunk up very bad.

[Shane S.]

Oh yea I saw all that gunk on the secondaries. I think it built up evern worse cause the secondaries werent opening for who knows how long cause of that plastic bushing that broke. What do you think of pressure washing the upper intake clean?

[Terry Haines]

..pressure wash is not a solvent,you need products like carb cleaners etc to dissolve the brown gasoline/oil gum and the carbon.

[Shane S.]

i know that, I have cleaned the lower intake thoroughly already but what about deep inside the upper intake where you cant reach? You can scrub where the throttle body bolts on & the under side ports but no where else. I figured I could spray cleaner inside & let it sit then hit the inside with the pressure washer to blast out what I cant reach with a wire brush. Im not going to do this to the lower intake of course cause everything is accessible. Im talking about the deep insides of the upper intake you cant reach. 

[Shane S.]

Ok got it back together, fired it up & it was misfiring & I had a flashing CEL. I shut it down & checked the codes, I had a multiple random misfire code & a cylinder number five misfire. I thought maybe the injector wasnt as clean as I thought, I checked all the wiring & it was fine. Before I put the UIM on I checked all the wiring on the injectors thoroughly & it was all connected & tight. I didnt touch any ignition wires or remove the plugs when the intake was off. Every wire connected & every nut & bolt was tight. I started it back up & it was still misfiring so I reved the engine a few times & let it idle for a min & it smoothed out. Cleared the codes & went for a ride & no more misfire or CEL. Maybe a plug got dirty when it was apart or that injector was not as clean as I thought & it cleared itself out? Maybe fuel hadnt quite reached the proper pressure or maybe air was in the line & it just needed to run for a min? Im going to drive it & see if it comes back. Still need to do a thorough test drive to see if the original issue is resolved. Seems to idle the same as before not 100% smooth but maybe Im being too picky. Seemed to drive through the entire RPM range well now though. What do you guys think? Im going to fill up & run some lucas injector cleaner after work today.  

[Shane S.]

Oh and my pressure washer idea worked great. I soaked and scrubbed all I could then blasted every port clean with the pressure washer after letting it soak in Carb cleaner. No one has any thoughts about my previous post? I drove the car yesterday & no more miss or cel. I should reset the computer though since fixing the leaks.

[Shane S.]

Last night I took it for a ride on a back road & decided to give it a work out. I got the rpms up to about 5000 then took it out of gear & drifted for a min to watch the rpms & it dropped very quick like it was going to stall then came back up to normal. Its idling at between 710 and 750 rpms according to my scanner. Drove it around for a while & it didnt do it again. Any ideas or thoughts about this? The major stumble seems to be gone though.

[2000SVTC]

If the ECU was reset due to being powered down - or if things are changed due to cleanup etc - it's going to take a little while to relearn proper settings for idle etc so as long as it keeps improving you're probably good.

[Shane S.]

Thanks for the input! Yea I drove it about 25 miles today and things seemed to smooth out a little but there is still a little popping when decelerating but its much better than it was & the stumble & jerking seems to be gone. When i got off the highway (cruising at 70 for 15 min) & came to a stop the rpms seemed to hang at 1200 for a while before dropping to 700 ish. It did that a good bit, first thing that comes to mind is the IAC but I just replaced that. Also when I got home I noticed some smoke coming out of the hood so I checked it out & its coming from the back of the engine somewhere. I couldnt really tell exactly where cause it was dark out but is definitely from the rear of the engine somewhere. It smelled like something burning, Im assuming a leaky valve cover gasket dripping on the exhaust or something like that. Its done that before so I know its not related to the gasket job I just did, just another issue to add to the list.