94 Quad 4 starting/idle problems

[BadBerettaZ26]

I'm having some weird running issues with my Z26 all of a sudden. When I first start it after not running for a while it will start but run roughly and miss for a bit, but will smooth out and run fine once I'm going. If I try to start it after running for any amount of time at all it will only start with 3/4 to full throttle down, and then it runs realllly rough for a minute til I can get it goin alright with the pedal. Even then it has a hesitation juuuust as I hit the gas, causing me to have to rev it up before releasing the clutch so it won't quit (people must think it's my first day with a stick haha). Also have to mention that during these startup times, the idle will randomly rev to between 2000-3000 rpm, then drop down eventually to around 1500, usually. It's been kinda hit or miss on how it will eventually run, but it usually runs like a top while driving. It hasn't given me a single CEL though, and yes the bulb does work

Plugs looked good, IAC was gunked up but cleaned thoroughly, changed fuel filter, FI cleaner, And I reset the computer tonight at work and did the idle relearn. It still started hard and stumbled for a bit til I got going, but it worked superb on the way home, no hesitation at all,and purred like a kitten while idling at home. Then I tried to start it again and same thing, no start unless I'm givin it lots of gas. And just now as I was typing this, I went out and tried it and it started like a charm and idled perfectly with no hesitation or miss. Shut it off and tried it again, no start.

TL;DR: 94 Quad has intermittent hard/rough starting issues, high idle, and hesitation. No codes. Any ideas before I start throwing parts at it? I know this place knows their Retta's, hope you can help!

[GTZryda]

Sounds like your fuel pressure regulator is bad. Pull the vacuum hose off the FPR, if gas is coming out of it then its bad.

[BadBerettaZ26]

Thanks for the reply gtz... i just went out and pulled the hose both while running and not running but had no fuel come out of it. It did start without giving it gas every time i tried it but still has a miss, but the miss goes away after idling for a minute or 2... It is quite random about how its gonna run, coming home from work this morning it worked bad, stalled on me at tim hortons drive thru (had to do some emergency flirting with the girl working to avoid embarrassment lol), and it had really high idle the whole way home to the point where it was basically driving itself, kinda like the cruise was on.... its hard to pinpoint what it might be cause its so random, but it just started doing this unexpectedly afer stopping at a store a few days ago so that leads me to believe its something relatively simple.... PITA for sure

Oh, also: its had a fairly bad exhaust rattle for about a month that i assumed was a piece of pipe behind the cat that the PO must have put in there, but yesterday while frigging around with the car i noticed the sound had changed, and while revving it i heard something go thru the exhaust and out the back. Still sounds to be a couple pieces of something in there but the rattle is nearly gone. Im wondering if the contents of my cat are coming apart and maybe its plugging it up or messing with the O2 sensor or something, but it sure doesnt seem like its plugged at least... just puttin all the info i can out there. Thanks again!




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[SuzukiGhostRider]

Sounds like your Cat is falling apart causing back pressure. Take it in and get the Cat removed.

[scd88ga]

I have the same car and my catalytic did the same thing... That's a good starting point for ya at least!

[BadBerettaZ26]

Take it in and get the Cat removed.

You spelled 'jack it up' wrong SGR

I wondered if this could be the issue but it runs so good while driving that i cant see it being the problem... regardless, i will be pullin off that piece of pipe and having a look inside the cat, if it would ever stop raining here... Do these quads really sound as bad with a hollow cat as I have read? The car is too quiet as it is so i was planning on putting a diff muffler on it but i dont want it to sound ricey. This will of course be after i have this problem fixed though...




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[SuzukiGhostRider]

It's a matter of opinion. I think it gives them a nice throaty note, with a hint of thush without the Cat in them. Other people disagreee.

As to the cat being clogged, when that crap that's falling apart in there (the "honeycomb") shifts just right, the car can flow half assed decent. When it shifts the OTHER way it's back logging exhaust into the motor, killing the engine. Had one go EXACTLY the same way on the woman's Achieva Quad. It finally just stalled her out completely one day coming off of I-40 and I had to go whack the Cat a few times (ROFL) and get it started and went STRAIGHT to the exhaust guy and had it cut out and replaced with a 22" Walker glass pack. Here's what the old cat looked like right after coming off:

[BadBerettaZ26]

Nice cat SGR! Last time i saw a cat like that was years ago on an old camaro i had, but that was after i had spent 10 minutes driving a jack handle up through it...

I'm kinda hoping it is that but still not completely convinced yet. Its gonna be nice for the next few days so i will have a chance to check it out. Think im also gonna pick up a set of plugs and wires (well, boots i guess), what do you recommend for the quad?


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[SuzukiGhostRider]

I run Autolite Iridiums in every Quad I own. Just updated the SCX and the woman's S (both Achieva's) to the Iridium. I won't run anything else anymore. Noticed, as per usual, an IMMEDIATELY smoother idle, snappier throttle response , and the MPG usually picks up 1-3 mpg. They'll run you anywhere from $5 to $8 apiece dependent upon where you get them from.

[BadBerettaZ26]

Well, I just went out and started it up to warm up for a minute before heading to the parts store, and the CEL finally came on! Downside is that I can't seem to check it with the jumper wire trick, is this one of the dreadful changeover years between obd1 and obd2? I suppose there's no way to check it on my own right? I have my jumper wire for obd1 and my scanner for obd2, but nothing for 1.5....

edit: Started off on my drive, made it about 10 minutes and it just intermittently lost all power and wouldn't pull itself. If I shove the clutch in and rev it, it will rev up good still. I had to keep doing that or droppin it down a gear to get me home. Also seemed to be a lot quieter too, but I dunno if that's real or you just planted a bug in my head that the cat is clogged. I've never had one clog up before so I dunno exactly how they act. So scratch the trip for plugs and stuff for now, as soon as the exhaust cools off I'm gonna investigate that cat.

[3X00-Modified]

You need an OBDI reader to pull the codes. It works on 94-95 OBDI.5 Beretta's

[BadBerettaZ26]

Well I have a diagnosis, I think these pics speak for themselves





It was plugged solid right at the outlet, I couldn't dislodge it with my fingers. So I got my trusty ol jackhandle and beat the crap out of it, start and rev, beat more crap out, start and rev again.... I got it all broke up and blown out, but the honeycomb must be in 2 halves inside the cat, front and rear if you will. I can see that there is still half of it in there but it is a nice perfectly flat surface that looks to be a complete full half. I left it like that for now at least, so I still have some cat efficiency there. I have to get a new piece of pipe for behind it so I may knock the rest out then.

Works a hundred times better now! Sound has maybe increased a bit, but I haven't driven it enough yet to notice much difference. Wife says it louder though. I still get an occasional miss or stumble at high rpm, with CEL coming on (which has never been on since I've had the car), but I'm hoping an ECM reset and new plugs will fix that. I imagine they got pretty fouled in the last couple days I've driven it, especially today when it plugged up completely.

So you guys were right, I've never had a clogged cat and never thought it would make it work like that! I expected power loss etc, but not all the high idle/hard starting, etc. Now I know! Thanks for your help! I'll let ya know how it works tomorrow after I take it for a good drive and get some parts

[SuzukiGhostRider]

Don't leave that cat in there with crap still in it. Remove it. You're going to wind up with the same issue again sooner or later otherwise. Trust me. That's why you still have issue sometimes now.

Glad to help.

[BadBerettaZ26]

ya I think I'm probably gonna punch the rest out when I take it back apart to put the new piece of pipe on it. It's in there correctly like it should be, but I figure it'll eventually get broken up as well. Gonna go get some plugs later today and do it all after that. My CEL comes and goes as of now, it's usually off when I first start it but then comes on after a few minutes of driving. Car is still working good however and pulls harder than I ever remember, for good reason I guess

3X00, what type of obd1 scanner would I need? A full scanner type of deal, or would one of those little code reader boxes from walmart suffice? I've always thought they were just basically a jumper wire in a case, cause they usually have only 4 prongs in em, 2 in the top right corner(for the A&B terminals), and 2 in bottom left corner, so it wouldn't matter which way it was plugged in...

[BadBerettaZ26]

Well I picked up some plugs, got the Autolite Iridiums like you suggested, ~9 bucks a piece. They only had 2 boots in stock so never got them yet. Came home and let er cool off before changing the plugs, and I also pulled the exhaust back apart and punched the rest of the honeycomb out of the cat. It had slid back in the cat about 4 inches so I figured I better get it out of there. Had a hell of a time breaking up one piece that was too big to come out, but I got it eventually. Car is working A1 now, no miss, starts right up and idles fine. The CEL is still coming on after ~ 5 mins of driving every time I drive it. Not sure what's causing that.

It got noticeably louder after punching the rest of the cat out, it's got a 'tinny, hollow' rasp to it now, along with that braaaapp noise when shifting. Sounds kinda like a beat up old civic atm :/ I'm thinking about either putting a cherry bomb glasspack in place of the cat, or picking up an $80 universal magnaflow cat at canadian tire. I like the louder sound but want to deepen the tinny sound down a bit, would a glasspack in place of the cat sound decent? I don't care about having a cat on it, just would like a nice deep tone to it without sounding too japanese

Should work like a 900hp Cup car with these in it!


old plugs a little fouled, Bosch Platinums


Noticed these tiny lines that looked like cracks on the coil housing, but you can see where I rubbed it off with my finger. Are these indicative of pending cracks, or just random dirt?


I looked at this code reader but it doesn't list anything for 94-95 Berettas, so I assume it doesn't handle obd 1.5...